| nuclear dynamics in arabidopsis thaliana. | the nucleus is a definitive feature of eukaryotic cells, comprising twin bilamellar membranes, the inner and outer nuclear membranes, which separate the nucleoplasmic and cytoplasmic compartments. nuclear pores, complex macromolecular assemblies that connect the two membranes, mediate communication between these compartments. to explore the morphology, topology, and dynamics of nuclei within living plant cells, we have developed a novel method of confocal laser scanning fluorescence microscopy u ... | 2000 | 10930466 |
| possible his to asp phosphorelay signaling in an arabidopsis two-component system. | we have so far cloned a cdna encoding a hybrid-type histidine kinase (athk1), three cdnas encoding phosphorelay intermediates (athp1-3), and four cdnas encoding response regulators (atrr1-4) from arabidopsis thaliana. to determine which molecules constitute a his to asp phosphorelay pathway, we examined protein-protein interactions between them using a pairwise yeast two-hybrid analysis, as an initial step. we detected a specific interaction between athk1 and athp1. we further examined protein-p ... | 2000 | 10930573 |
| sequence diversification of the fk506-binding proteins in several different genomes. | sequences of fk506-binding proteins (fkbps) from four genomes of the following organisms were compared: the prokaryote escherichia coli, the lower eukaryote saccharomyces cerevisiae, the plant arabidopsis thaliana, the nematode caenorhabditis elegans and a composite of 14 unique fkbps from two mammalian organisms homo sapiens (man) and mus musculus (domestic mouse). a singular fk506-like binding domain (fkbd) has about 12 kda and occurs in the form of archetypal fkbp-12 and as a part of differen ... | 2000 | 10931176 |
| the dihydrolipoyl acyltransferase (bce2) subunit of the plant branched-chain alpha-ketoacid dehydrogenase complex forms a 24-mer core with octagonal symmetry. | little is known of the plant branched-chain alpha-ketoacid dehydrogenase complex. we have undertaken a detailed study of the structure of the dihydrolipoyl acyltransferase (bce2) subunit that forms the core of the complex, to which two other enzymes attach. mature arabidopsis thaliana bce2 was expressed in escherichia coli. the soluble recombinant protein was purified using a superose 6 size-exclusion column to >90% homogeneity and was catalytically active. the recombinant protein formed a stabl ... | 2000 | 10933498 |
| complex formation between potyvirus vpg and translation eukaryotic initiation factor 4e correlates with virus infectivity. | the interaction between the viral protein linked to the genome (vpg) of turnip mosaic potyvirus (tumv) and the translation eukaryotic initiation factor eif(iso)4e of arabidopsis thaliana has previously been reported. eif(iso)4e binds the cap structure (m(7)gpppn, where n is any nucleotide) of mrnas and has an important role in the regulation in the initiation of translation. in the present study, it was shown that not only did vpg bind eif(iso)4e but it also interacted with the eif4e isomer of a ... | 2000 | 10933678 |
| a glycoconjugate from corms of saffron plant (crocus sativus l.) inhibits root growth and affects in vitro cell viability. | a glycoconjugate has been characterized from saffron corms (crocus sativus l.) that inhibits the growth of roots of nicotiana tabacum and arabidopsis thaliana, at concentrations ranging from 1-100 micrograms m-3. roots of seedlings grown in the presence 0.1 microgram m-3 glycoconjugate showed bulging of epidermal cells, whereas at 10 micrograms m-3, roots were completely devoid of hairs. at 100 micrograms m-3 glycoconjugate the cell walls of the root vascular tissues were thicker and, overall, t ... | 2000 | 10938865 |
| a novel ubiquitous family of putative efflux transporters. | we describe a novel family of putative efflux transporters (pet) found in bacteria, yeast and plants. none of the members of the pet family has been functionally characterized. the bacterial and yeast proteins display a duplicated internal repeat element consisting of an n-terminal hydrophobic sequence of about 170 residues, exhibiting six putative transmembrane alpha-helical spanners (tmss), followed by a large (230 residue), c-terminal, hydrophilic, cytoplasmic domain. the plant proteins exhib ... | 2000 | 10939244 |
| cdna-aflp display for the isolation of peronospora parasitica genes expressed during infection in arabidopsis thaliana. | to identify genes from the obligatory biotrophic oomycete peronospora parasitica that are expressed during infection in arabidopsis thaliana we employed cdna-amplified fragment length polymorphism (aflp) display. cdna-aflp fragments from infected and non-infected leaves were separated in parallel by gel electrophoresis and displayed by autoradiography. most differential gene fragments were derived from p. parasitica. | 2000 | 10939263 |
| expression of threonine synthase from solanum tuberosum l. is not metabolically regulated by photosynthesis-related signals or by nitrogenous compounds. | although the control of carbon fixation and nitrogen assimilation has been studied in detail, little is known about the regulation of carbon and nitrogen flow into amino acids. in this paper the isolation of a cdna encoding threonine synthase is reported (ts; ec 4.2.99.2) from a leaf lambda zap ii-library of solanum tuberosum l. and the transcriptional regulation of the respective gene expression in response to metabolic changes. the pattern of expression of ts by feeding experiments of detached ... | 2000 | 10940468 |
| genomic and functional characterization of the oas gene family encoding o-acetylserine (thiol) lyases, enzymes catalyzing the final step in cysteine biosynthesis in arabidopsis thaliana. | the final step of cysteine biosynthesis in plants is catalyzed by o-acetylserine (thiol) lyase (oas-tl), which occurs as several isoforms found in the cytosol, the plastids and the mitochondria. genomic dna blot hybridization and isolation of genomic clones indicate single copy genes (oasa1, oasa2, oasb and oasc) that encode the activities of oas-tl a, b and c found in separate subcellular compartments in the model plant arabidopsis thaliana. sequence analysis reveals that the newly discovered o ... | 2000 | 10940562 |
| clonal analysis of the arabidopsis root confirms that position, not lineage, determines cell fate. | the cellular organization of the arabidopsis thaliana (l.) heynh. root meristem suggests that a regular pattern of cell divisions occurs in the root tip. deviations from this pattern of division might be expected to disrupt the organization of cells and tissues in the root. a clonal analysis of the 3-d-old primary root meristem was carried out to determine if there is variability in division patterns, and if so to discover their effect on cellular organization in the root. clones induced in the ... | 2000 | 10945213 |
| molecular cloning and characterization of a cdna encoding proline transporter in rice. | a cdna encoding a proline (pro) transporter (prot) was isolated and characterized from a cdna library prepared from 14-d-old seedlings of oryza sativa cv. akibare. the deduced amino acid sequence of the rice prot protein (osprot) had 68.8% homology to the prot protein 1 from arabidopsis thaliana and 59.6% homology to that from lycopersicon esculentum. northern blot analysis revealed that the gene for osprot (osprot) was expressed in all organs examined, comparatively strongly in leaf sheath and ... | 2000 | 10945345 |
| expression of bra r 1 gene in transgenic tobacco and bra r 1 promoter activity in pollen of various plant species. | bra r 1 encodes a ca2+-binding protein specifically expressed in anthers of brassica rapa. in this study, we isolated a genomic clone of bra r 1 and found sequences similar to pollen box core motifs and lat56/59 box, pollen-specific cis-acting element, in the 5' upstream region of bra r 1. reporter gene fusion revealed that the bra r 1 promoter directs male gametophytic expression in nicotiana tabacum, arabidopsis thaliana and b. napus, showing strong expression in mature pollen grains similar t ... | 2000 | 10945346 |
| a method for expression cloning of transporter genes by screening yeast for uptake of radiolabelled substrate. | a method has been developed for the cloning of plasma membrane transporters by screening yeast transformed with a cdna library for the accumulation of radiolabelled substrate. the applicability of the method is demonstrated by cloning the amino acid permease aap1. a yeast mutant defective in proline uptake was transformed with an arabidopsis thaliana cdna library and plated on medium supplemented with l-[u-(14)c]proline. yeast colonies accumulating radiolabelled proline were identified by autora ... | 2000 | 10948222 |
| phytobilin biosynthesis: the synechocystis sp. pcc 6803 heme oxygenase-encoding ho1 gene complements a phytochrome-deficient arabidopsis thalianna hy1 mutant. | the phytobilin chromophores of phycobiliproteins and phytochromes are biosynthesized from heme in a pathway that begins with the opening of the tetrapyrrole macrocycle of protoheme to form biliverdin ixalpha, in a reaction catalyzed by heme oxygenase. an arabidopsis thaliana hy1 mutant was previously shown to be deficient in phytochrome responses, and these responses were regained when the plants were administered biliverdin ixalpha. a heme oxygenase-encoding gene, ho1, was recently cloned from ... | 2000 | 10949378 |
| characterization of two sulfurtransferase isozymes from arabidopsis thaliana. | sulfurtransferases transfer a sulfane atom from a donor substrate to a thiophilic acceptor molecule. recently a sulfurtransferase specific for the substrate 3-mercaptopyruvate was isolated from arabidopsis thaliana [papenbrock, j. & schmidt, a. (2000) eur. j. biochem. 267, 145-154]. in this study a second sulfurtransferase from arabidopsis was characterized and compared to the enzyme described previously. sequences of the mature proteins had an identity of 77.7%. the plant sulfurtransferases for ... | 2000 | 10951216 |
| the restoration of fertility in male sterile tobacco demonstrates that transgene silencing can be mediated by t-dna that has no dna homology to the silenced transgene. | male sterile tobacco plants expressing a pathogenesis-related (pr) beta-1,3-glucanase gene driven by the arabidopsis thaliana a3 or a9 tapetum-specific promoter, were partially restored to fertility by retransformation with a range of pa9-driven sense and antisense pr glucanase fragments. the restored plants exhibited improved seed set. pr glucanase protein was undetectable in the anthers of these plants and there was an associated increase in microsporocyte callose, the structural target of the ... | 2000 | 10951693 |
| transgenic trifolium repens with foliage accumulating the high sulphur protein, sunflower seed albumin. | with the aim of increasing the rumen-protected level of the sulphur amino acids cysteine and methionine in trifolium repens, we introduced the coding sequence of the sunflower seed albumin (ssa) into t. repens by agrobacterium tumefaciens-mediated transformation. the ssa gene was modified such that the protein would be localised to the endoplasmic reticulum (er). four different t-dna constructions all containing the ssa gene driven by either the promoter of a gene encoding the small subunit of r ... | 2000 | 10951694 |
| intercodon dinucleotides affect codon choice in plant genes. | in this work, 710 cdss corresponding to over 290 000 codons equally distributed between brassica napus, arabidopsis thaliana, lycopersicon esculentum, nicotiana tabacum, pisum sativum, glycine max, oryza sativa, triticum aestivum, hordeum vulgare and zea mays were considered. for each amino acid, synonymous codon choice was determined in the presence of a, g, c or t as the initial nucleotide of the subsequent triplet; data were statistically analysed under the hypothesis of an independent assort ... | 2000 | 10954603 |
| promoter analysis of pyk20, a gene from arabidopsis thaliana. | the gene pyk20 which has been isolated from arabidopsis thaliana encodes a protein with a glutamine-rich domain in the c-terminal region. the transcription of this gene was shown to be induced in feeding sites of root-parasitic nematodes (heterodera schachtii), in roots infected by a fungus-like organism (plasmodiophora brassicae), by plant hormone treatment, and by wounding. in order to identify functional promoter regions seven different 5' and 3' pyk20 promoter (ppyk20) deletion fragments wer ... | 2000 | 10960738 |
| auxin transport: providing a sense of direction during plant development. | auxins are key regulators of plant development. plants employ a specialized delivery system termed polar auxin transport to convey indole-3-acetic acid from source to target tissues. auxin transport is mediated by the combined activities of specialized influx and efflux carriers. mutational approaches in the model plant, arabidopsis thaliana, have led to the molecular genetic characterization of putative auxin influx and efflux carrier components, aux1 and atpin1. both genes belong to distinct g ... | 2000 | 10961944 |
| trypanosoma cruzi: a putative vacuolar atp synthase subunit and a caax prenyl protease-encoding gene, as examples of gene identification in genome projects. | an international genome program has been initiated to increase the knowledge about the trypanosoma cruzi genome and thereby find effective tools to treat chagas' disease. we here report the molecular characterization of two novel genes found in the course of this project. two of the open reading frames (orf) identified in the sequencing of the third smallest chromosome of the cl brener strain of t. cruzi were selected for further molecular characterization due to their similarity to genes with i ... | 2000 | 10964645 |
| cre/lox-mediated recombination in arabidopsis: evidence for transmission of a translocation and a deletion event. | cre recombinase was used to mediate recombination between a chromosomally introduced loxp sequence in arabidopsis thaliana (35s-lox-cre) and transferred dna (t-dna) originating from agrobacterium tumefaciens (plox-npt), carrying a single loxp sequence. constructs were designed for specific cre-mediated recombination between the two lox sites, resulting in restoration of neomycin phosphotransferase (nptii) expression at the target locus. kanamycin resistant (km(r)) recombinants were obtained with ... | 2000 | 10968257 |
| abscisic aldehyde oxidase in leaves of arabidopsis thaliana. | abscisic acid (aba) is a plant hormone involved in seed development and responses to various environmental stresses. oxidation of abscisic aldehyde is the last step of aba biosynthesis and is catalysed by aldehyde oxidase (ec 1.2.3.1). we have reported the occurrence of three isoforms of aldehyde oxidase, aoalpha, aobeta and aogamma, in arabidopsis thaliana seedlings, but none oxidized abscisic aldehyde. here we report a new isoform, aodelta, found in rosette leaf extracts, which efficiently oxi ... | 2000 | 10972874 |
| analysis of the g-overhang structures on plant telomeres: evidence for two distinct telomere architectures. | telomeres are highly conserved structures essential for maintaining the integrity of eukaryotic genomes. in yeast, ciliates and mammals, the g-rich strand of the telomere forms a 3' overhang on the chromosome terminus. here we investigate the architecture of telomeres in the dicot plants silene latifolia and arabidopsis thaliana using the pent (primer extension/nick translation) assay. we show that both arabidopsis and silene telomeres carry g-overhangs longer than 20-30 nucleotides. however, in ... | 2000 | 10972889 |
| the human trna(m(2)(2)g(26))dimethyltransferase: functional expression and characterization of a cloned htrm1 gene. | this paper presents the first example of a complete gene sequence coding for and expressing a biologically functional human trna methyltransferase: the htrm1 gene product trna(m(2)(2)g)dimethyltransferase. we isolated a human cdna (1980 bp) made from placental mrna coding for the full-length (659 amino acids) human trm1 polypeptide. the sequence was fairly similar to saccharomyces cerevisiae trm1p, to caenorhabditis elegans trm1p and to open reading frames (orfs) found in mouse and a plant (arab ... | 2000 | 10982862 |
| transcriptional activation by the phd finger is inhibited through an adjacent leucine zipper that binds 14-3-3 proteins. | the phd finger, a cys(4)-his-cys(3) zinc finger, is found in many regulatory proteins from plants or animals which are frequently associated with chromatin-mediated transcriptional regulation. we show here that the phd finger activates transcription in yeast, plant and animal cells. in plant homeodomain transcription factors the phd finger is combined with an upstream leucine zipper. both domains together form a highly conserved 180 amino acid region called the zip/phdf motif and transcriptional ... | 2000 | 10982874 |
| a quadruple photoreceptor mutant still keeps track of time. | time measurement and light detection are inextricably linked. cryptochromes, the blue-light photoreceptors shared between plants and animals, are critical for circadian rhythms in flies and mice [1-3]. wc-1, a putative blue-light photoreceptor, is also essential for the maintenance of circadian rhythms in neurospora [4]. in contrast, we report here that in arabidopsis thaliana the double mutant lacking the cryptochromes cry1 and cry2, and even a quadruple mutant lacking the red/ far-red photorec ... | 2000 | 10985392 |
| the x-ray structure of the fmn-binding protein athal3 provides the structural basis for the activity of a regulatory subunit involved in signal transduction. | the arabidopsis thaliana hal3 gene product encodes for an fmn-binding protein (athal3) that is related to plant growth and salt and osmotic tolerance. athal3 shows sequence homology to schal3, a regulatory subunit of the saccharomyces cerevisae serine/threonine phosphatase ppz1. it has been proposed that athal3 and schal3 have similar roles in cellular physiology, as arabidopsis transgenic plants that overexpress athal3 and yeast cells that overexpress schal3 display similar phenotypes of improv ... | 2000 | 10986463 |
| arabidopsis thaliana germin-like proteins: common and specific features point to a variety of functions. | germin-like proteins (glps) are ubiquitous plant proteins encoded by diverse multigene families. it is not known whether they share germin's unusual biochemical properties and oxalate oxidase activity. using specific antibodies, we have studied three glps (atger1. atger2 and atger3) in arabidopsis thaliana (l.) heynh. as well as in transgenic tobacco (nicotiana tabacum l.) plants overexpressing these proteins. like wheat ( triticum aestivum l.) germin, these arabidopsis glps are associated with ... | 2000 | 10987552 |
| variation and phylogenetic utility of the arabidopsis thaliana rps2 homolog in various species of the tribe brassiceae. | our objective was to analyze the evolutionary paths of cultivated diploid brassica species and a few related wild species (tribe brassiceae) in relation to arabidopsis thaliana (tribe arabidae), using the rps2 sequence. rps2 confers resistance to pseudomonas syringae in a. thaliana. we found that similar to arabidopsis, the rps2 homolog in brassica species is present in a single copy. primers based in the rps2 sequence amplified rps2 homologs from the other species. maximum-parsimony analysis ba ... | 2000 | 10991796 |
| glutathione biosynthesis in arabidopsis trichome cells. | in arabidopsis thaliana, trichome cells are specialized unicellular structures with uncertain functions. based on earlier observations that one of the genes involved in cysteine biosynthesis (atcys-3a) is highly expressed in trichomes, we have extended our studies in trichome cells to determine their capacity for glutathione (gsh) biosynthesis. first, we have analyzed by in situ hybridization the tissue-specific expression of the genes atcys-3a and sat5, which encode o-acetylserine(thio)lyase (o ... | 2000 | 10995473 |
| abolishment of proton pumping and accumulation in the e1p conformational state of a plant plasma membrane h+-atpase by substitution of a conserved aspartyl residue in transmembrane segment 6. | the plasma membrane h(+)-atpase aha2 of arabidopsis thaliana, which belongs to the p-type atpase superfamily of cation-transporting atpases, pumps protons out of the cell. to investigate the mechanism of ion transport by p-type atpases we have mutagenized asp(684), a residue in transmembrane segment m6 of aha2 that is conserved in ca(2+)-, na(+)/k(+)-, h(+)/k(+)-, and h(+)-atpases and which coordinates ca(2+) ions in the serca1 ca(2+)-atpase. we describe the expression, purification, and biochem ... | 2000 | 10995773 |
| fap1, a homologue of human transcription factor nf-x1, competes with rapamycin for binding to fkbp12 in yeast. | the immunosuppressive drug rapamycin binds to the peptidyl-prolyl cis-trans isomerase fkbp12, and this complex arrests growth of yeast cells and activated t lymphocytes in the g1 phase of the cell cycle. in yeast, loss-of-function mutations in fpr1, the gene encoding fkbp12, or dominant gain-of-function mutations in tor1 and tor2, the genes encoding the physical targets of the fkbp12-rapamycin complex, confer rapamycin resistance. here, we report the cloning and characterization of a novel gene, ... | 2000 | 10998178 |
| cre-lox site-specific recombination between arabidopsis and tobacco chromosomes. | to create hybrid chromosomes, we tested the cre-lox system to mediate recombination between arabidopsis thaliana and nicotiana tabacum chromosomes. protoplasts of the two plants were fused to allow site-specific recombination to join a promoter from tobacco to a hygromycin resistance coding-region from arabidopsis. the expected recombination junction was detected in hygromycin-resistant calli. analysis of one hybrid suspension cell line revealed the presence of markers corresponding to the north ... | 2000 | 10998183 |
| arabidopsis thaliana and saccharomyces cerevisiae nhx1 genes encode amiloride sensitive electroneutral na+/h+ exchangers. | sodium at high millimolar levels in the cytoplasm is toxic to plant and yeast cells. sequestration of na(+) ions into the vacuole is one mechanism to confer na(+)-tolerance on these organisms. in the present study we provide direct evidence that the arabidopsis thaliana at-nhx1 gene and the yeast nhx1 gene encode low-affinity electroneutral na(+)/h(+) exchangers. we took advantage of the ability of heterologously expressed at-nhx1 to functionally complement the yeast nhx1-null mutant. experiment ... | 2000 | 10998367 |
| cloning and expression of cdnas encoding plant v-atpase subunits in the corresponding yeast null mutants. | complementation of yeast null mutants is widely used for cloning of homologous genes from heterologous sources. we have used this method to clone the relevant v-atpase genes from lemon fruit and arabidopsis thaliana cdna libraries. the ph levels are very different in the vacuoles of the lemon fruit and the a. thaliana, yet both are the result of the activity of the same enzyme complex, namely the v-atpase. in order to investigate the mechanism that enables the enzyme to maintain such differences ... | 2000 | 11004467 |
| functional identification of the glycerol permease activity of arabidopsis thaliana nlm1 and nlm2 proteins by heterologous expression in saccharomyces cerevisiae. | nlm proteins (nod26-like major intrinsic proteins) from plants contain amino acid sequence signatures which can be found in aquaporins including plant plasma membrane intrinsic proteins and tonoplast intrinsic proteins and glycerol permeases such as the escherichia coli glpf and the yeast fps1 proteins. heterologous expression of two members of the nlm subgroup from arabidopsis thaliana (atnlm1 and atnlm2) in baker's yeast demonstrated the glycerol permease activity in addition to the previously ... | 2000 | 11007982 |
| transposition of maize ac/ds transposable elements in the yeast saccharomyces cerevisiae. | excision by transposons is associated with chromosome breaks; generally, host-cell proteins repair this damage, often introducing mutations. many transposons also use host proteins in the transposition mechanism or in regulation. transposition in systems lacking host factors that influence the behaviour of these transpositions is useful in determining what those factors are and how they work. in addition, features of transposition and regulation intrinsic to the element itself can be determined. ... | 2000 | 11017074 |
| a comparison of peronospora parasitica (downy mildew) isolates from arabidopsis thaliana and brassica oleracea using amplified fragment length polymorphism and internal transcribed spacer 1 sequence analyses. | amplified fragment length polymorphism (aflp) fingerprints and internal transcribed spacer 1 (its1) sequences from 27 peronospora parasitica isolates (collected from arabidopsis thaliana or brassica oleracea), 5 albugo candida isolates (from the same hosts and from capsella bursa-pastoris), and 1 bremia lactucae isolate (from lactuca sativa) were compared. the aflp analysis divided the isolates into five groups that correlated with taxonomic species and, in most cases, with host origin. the only ... | 2000 | 11017765 |
| ceo1, a new protein from arabidopsis thaliana, protects yeast against oxidative damage. | the saccharomyces cerevisiae strain wyt, deficient in the yap1 transcription factor, was used in a molecular screen to identify genes from arabidopsis thaliana that could overcome the oxidative stress-sensitive phenotype of these yeast cells. a cdna named ceo1 increased the tolerance to oxidative damage caused by tert-butylhydroperoxide of both the yap1(-) mutant and the wild-type yeast. additionally, in yap1(-) yeast, ceo1 also induced cross-tolerance to oxidative damage caused by hydrogen pero ... | 2000 | 11018516 |
| is plant biotin holocarboxylase synthetase a bifunctional enzyme? | holocarboxylase synthetases (hcss) catalyse the biotinylation of biotin-dependent carboxylases in both prokaryotes and eukaryotes. in escherichia coli and bacillus subtilis, the protein also acts as a transcriptional repressor that regulates the synthesis of biotin. previously, we isolated and characterized a cdna encoding an arabidopsis thaliana hcs and subsequently assigned this enzyme form to the chloroplast compartment. to investigate whether or not the arabidopsis protein may function as a ... | 2000 | 11019362 |
| substrate-dependent mutant complementation to select fatty acid desaturase variants for metabolic engineering of plant seed oils. | we demonstrate that naturally occurring c(14) and c(16)-specific acyl-acyl carrier protein (acp) desaturases from plants can complement the unsaturated fatty acid (ufa) auxotrophy of an escherichia coli faba/fadr mutant. under the same growth conditions, c(18)-specific delta(9)-stearoyl (18:0)-acp desaturases are unable to complement the ufa auxotrophy. this difference most likely results from the presence of sufficient substrate pools of c(14) and c(16) acyl-acps but a relative lack of c(18) ac ... | 2000 | 11027301 |
| coordinated plant defense responses in arabidopsis revealed by microarray analysis. | disease resistance is associated with a plant defense response that involves an integrated set of signal transduction pathways. changes in the expression patterns of 2,375 selected genes were examined simultaneously by cdna microarray analysis in arabidopsis thaliana after inoculation with an incompatible fungal pathogen alternaria brassicicola or treatment with the defense-related signaling molecules salicylic acid (sa), methyl jasmonate (mj), or ethylene. substantial changes (up- and down-regu ... | 2000 | 11027363 |
| characterization of five new low-molecular-mass trypsin inhibitors from white mustard (sinapis alba l.) seed. | five new low-molecular-mass trypsin inhibitors belonging to the rti/mti-2 family were identified from white mustard (sinapis alba l. ; mti-2) seed. purified mti-2 consisted of a peptide mixture, displaying ile or arg at position 43, trp or kynurenine (kyn) at position 44, and c-terminal ragged ends. the occurrence of ile or arg at position 43 suggested that mti-2 inhibitors originated from different genes. the presence of 5-oxo-proline (pyroglutamic acid; 5-oxopro1) and kyn44 reflected post-tran ... | 2000 | 11029593 |
| arabidopsis dna ligase iv is induced by gamma-irradiation and interacts with an arabidopsis homologue of the double strand break repair protein xrcc4. | rejoining of single- and double-strand breaks (dsbs) introduced in dna during replication, recombination, and dna damage is catalysed by dna ligase enzymes. eukaryotes possess multiple dna ligase enzymes, each having distinct roles in cellular metabolism. double-strand breaks in dna, which can occur spontaneously in the cell or be induced experimentally by gamma-irradiation, represent one of the most serious threats to genomic integrity. non-homologous end joining (nhej) rather than homologous r ... | 2000 | 11029705 |
| cytokinin and gibberellin activate samads a, a gene apparently involved in regulation of the floral transition in sinapis alba. | in plants of sinapis alba induced to flower by one long day, the mads box gene, samads a, is expressed initially in the central corpus (l3 cells) of the shoot apical meristem (sam), about 1.5-2 days before initiation of the first floral meristem. we have combined a physiological approach by testing the effects of three putative floral signals on samads a expression in the sam of s. alba plants with a transgenic approach using arabidopsis thaliana plants. a single application of a low dose of a c ... | 2000 | 11029708 |
| active oxygen species as mediators of plant immunity: three case studies. | a burst of active oxygen species (aos) is known to be involved in local cell death as part of plant defence against pathogens. it is, however, under dispute to what extent aos can induce pathogen resistance and immunity throughout the plant. three experimental strategies that reveal a primary role for aos and a surprisingly low chemical and spatial specificity are now described for tobacco and arabidopsis thaliana plants. ozone is a gaseous aos that was applied to non-transgenic plants. hydrogen ... | 2000 | 11030422 |
| species-specific double-strand break repair and genome evolution in plants. | even closely related eukaryotic species may differ drastically in genome size. while insertion of retroelements represents a major source of genome enlargement, the mechanism mediating species- specific deletions is fairly obscure. we analyzed the formation of deletions during double-strand break (dsb) repair in arabidopsis thaliana and tobacco, two dicotyledonous plant species differing >20-fold in genome size. dsbs were induced by the rare cutting restriction endonuclease i-sce:i and deletions ... | 2000 | 11032823 |
| arabidopsis thaliana defense-related protein eli3 is an aromatic alcohol:nadp+ oxidoreductase. | we expressed a cdna encoding the arabidopsis thaliana defense-related protein eli3-2 in escherichia coli to determine its biochemical function. based on a protein database search, this protein was recently predicted to be a mannitol dehydrogenase [williamson, j. d., stoop, j. m. h., massel, m. o., conkling, m. a. & pharr, d. m. (1995) proc. natl. acad. sci. usa 92, 7148-7152]. studies on the substrate specificity now revealed that eli3-2 is an aromatic alcohol: nadp+ oxidoreductase (benzyl alcoh ... | 1996 | 11038530 |
| plant initiation factor 3 subunit composition resembles mammalian initiation factor 3 and has a novel subunit. | eukaryotic initiation factor 3 (eif3) is a multisubunit complex that is required for binding of mrna to 40 s ribosomal subunits, stabilization of ternary complex binding to 40 s subunits, and dissociation of 40 and 60 s subunits. these functions and the complex nature of eif3 suggest multiple interactions with many components of the translational machinery. recently, the subunits of mammalian and saccharomyces cerevisiae eif3 were identified, and substantial differences in the subunit compositio ... | 2001 | 11042177 |
| [phenotypic changes in transgenic tobacco plants with an antisense form of the hmg1 gene]. | tobacco plants were genetically transformed with the arabidopsis thaliana heterologous hmg1 gene encoding 3-hydroxy-3-methylglutaryl-coa reductase, a key enzyme involved in the metabolism of terpenoid compounds. the hmg1 gene was inserted under the control of the 35s rna double promoter from the cauliflower mosaic virus (camv 35s) both in direct and reverse orientation relative to the promoter. dna analysis by polymerase chain reaction (pcr) and southern blotting confirmed the transgenic nature ... | 2000 | 11042806 |
| [effect of chronic irradiation on the genetic structure of natural populations of arabidopsis thaliana (l.) heynh]. | the genetic structure of arabidopsis thaliana populations from in the chernobyl zone of radioactive contamination was studied. the dynamics of genotypic and allele frequencies of eight polymorphic loci were described. analysis of the results obtained and earlier data revealed selection for loci per1 and acp2. sharp fluctuations of allele frequencies were observed in consecutive generations of chronically irradiated a. thaliana populations. these fluctuations led to replacement of the most freque ... | 2000 | 11042811 |
| a second t-region of the soybean-supervirulent chrysopine-type ti plasmid ptichry5, and construction of a fully disarmed vir helper plasmid. | agrobacterium tumefaciens chry5, which is particularly virulent on soybeans, induces tumors that produce a family of amadori-type opines that includes deoxyfructosyl glutamine (dfg) and its lactone, chrysopine (chy). cosmid clones mapping to the right of the known oncogenic t-region of ptichry5 conferred amadori opine production on tumors induced by the nopaline strain c58. sequence analysis of dna held in common among these cosmids identified two 25-bp, direct repeats flanking an 8.5-kb segment ... | 2000 | 11043469 |
| susceptibility and symptom development in arabidopsis thaliana to tobacco mosaic virus is influenced by virus cell-to-cell movement. | to identify host factors that regulate susceptibility to tobacco mosaic virus (tmv), 14 arabidopsis thaliana ecotypes were screened for their ability to support tmv systemic movement. the susceptibility phenotypes observed included one ecotype that permitted rapid tmv movement accompanied by symptoms, nine ecotypes that allowed a slower intermediate rate of systemic movement without symptoms, and four ecotypes that allowed little or no systemic tmv movement. molecular comparisons between ecotype ... | 2000 | 11043475 |
| purification of recombinant arabidopsis thaliana dehydrins by metal ion affinity chromatography. | in this study we describe a novel method for purification of arabidopsis thaliana dehydrins overproduced in escherichia coli. the cdnas corresponding to the four dehydrin genes rab18, lti29, lti30, and cor47 were inserted into a bacterial expression vector under an isopropyl beta-d-thiogalactopyranoside (iptg) inducible bacterial promoter. after iptg induction all four proteins accumulated in high amounts. the recombinant proteins were efficiently purified to over 95% purity with a three-step pu ... | 2000 | 11049741 |
| expression, purification, and characterization of the protein repair l-isoaspartyl methyltransferase from arabidopsis thaliana. | protein l-isoaspartate (d-aspartate) o-methyltransferase (ec 2.1.1. 77) is a repair enzyme that methylates abnormal l-isoaspartate residues in proteins which arise spontaneously as a result of aging. this enzyme initiates their conversion back into the normal l-aspartate form by a methyl esterification reaction. previously, partial cdnas of this enzyme were isolated from the higher plant arabidopsis thaliana. in this study, we report the cloning and expression of a full-length cdna of l-isoaspar ... | 2000 | 11049748 |
| novel scamps lacking npf repeats: ubiquitous and synaptic vesicle-specific forms implicate scamps in multiple membrane-trafficking functions. | in vertebrates, secretory carrier membrane proteins (scamps) 1-3 constitute a family of putative membrane-trafficking proteins composed of cytoplasmic n-terminal sequences with npf repeats, four central transmembrane regions (tmrs), and a cytoplasmic tail. scamps probably function in endocytosis by recruiting eh-domain proteins to the n-terminal npf repeats but may have additional functions mediated by their other sequences. we now demonstrate that scamps form a much larger and more heterogeneou ... | 2000 | 11050114 |
| purification, molecular cloning, and sequence analysis of sucrose-6f-phosphate phosphohydrolase from plants. | sucrose-6(f)-phosphate phosphohydrolase (spp; ec ) catalyzes the final step in the pathway of sucrose biosynthesis and is the only enzyme of photosynthetic carbon assimilation for which the gene has not been identified. the enzyme was purified to homogeneity from rice (oryza sativa l.) leaves and partially sequenced. the rice leaf enzyme is a dimer with a native molecular mass of 100 kda and a subunit molecular mass of 50 kda. the enzyme is highly specific for sucrose 6(f)-phosphate with a k(m) ... | 2000 | 11050182 |
| root hairiness: effect on fluid flow and oxygen transfer in hairy root cultures. | the effect of root hairiness on fluid flow and oxygen transfer in hairy root cultures was investigated using wild-type, transgenic and root-hair mutants of arabidopsis thaliana. the root hair morphologies of the a. thaliana lines were hairless, short hairs, moderately hairy (wild-type) and excessively hairy, and these morphologies were maintained after transformation of seedlings with agrobacterium rhizogenes. filtration experiments were used to determine the permeability of packed beds of roots ... | 2000 | 11051417 |
| increased leakiness of the tetracycline-inducible triple-op promoter in dividing cells renders it unsuitable for high inducible levels of a dominant negative cdc2aat gene. | a tetracycline-inducible promoter system was used to generate transgenic tobacco plants that confer inducible expression of the wild type or a dominant negative allele of the gene coding for the cyclin-dependent kinase (cdk) of arabidopsis thaliana cdc2aat. although the total extractable cdk activity was doubled, the induced expression of the wild-type cdc2aat did not correlate with any change of the cell cycle kinetics. an increase of cdk activity upon cdc2aat expression was only seen in dividi ... | 2000 | 11053453 |
| cef, a sec24 homologue of arabidopsis thaliana, enhances the survival of yeast under oxidative stress conditions. | budding yeast strains that produced the arabidopsis thaliana protein cef or its amino-terminal proline-rich domain were more tolerant to hydroperoxides. cef is homologous to animal and yeast sec24 proteins. these data suggest that cef plays a protective role through protein transport during growth under pro-oxidant conditions. | 2000 | 11053466 |
| oxidative stress, heat shock and drought differentially affect expression of a tobacco protein phosphatase 2c. | a protein phosphatase 2c (pp2c)-homologous cdna was isolated from nicotiana tabacum (ntpp2c1). the deduced protein sequence of 416 amino acids showed the highest degree of similarity to the pp2c of arabidopsis thaliana (atpp2ca) implicated in abscisic acid signalling. the expression of ntpp2c1 was strongly induced by drought, but repressed by oxidative stress and heat shock. it is suggested that ntpp2c1 operates at the junction of drought, heat shock and oxidative stress. | 2000 | 11053467 |
| molecular cloning, functional complementation in saccharomyces cerevisiae and enzymatic properties of phosphatidylinositol synthase from the protozoan parasite toxoplasma gondii. | the obligate intracellular parasite toxoplasma gondii, the causative agent of toxoplasmosis, switches between the rapidly dividing tachyzoite and the slowly replicating bradyzoite in intermediate hosts such as humans and domestic animals. we have recently identified a bradyzoite cdna encoding a putative phosphatidylinositol (ptdins) synthase using a subtractive library [yahiaoui, b., dzierszinski, f., bernigaud, a., slomianny, c., camus, d., and tomavo, s. (1999) mol. biochem. parasitol. 99, 223 ... | 2000 | 11054108 |
| molecular evidence of a unique lipoamide dehydrogenase in plastids: analysis of plastidic lipoamide dehydrogenase from arabidopsis thaliana. | lipoamide dehydrogenase is a subunit of the alpha-ketoacid dehydrogenases and the glycine decarboxylase complex in mitochondria, and the pyruvate dehydrogenase complex in plastids. we report here the unexpected finding of two plastidic isoforms of lipoamide dehydrogenase from arabidopsis thaliana that are different from the mitochondrial form of the enzyme. the cdna clones were confirmed by sequence alignment analysis and their location verified by chloroplast import assay. they are single copy ... | 2000 | 11056213 |
| effects of halone 1301 on lepidium sativum, petunia hybrida and phaseolus vulgaris. | halone 1301 belongs to a group of widely used fire repellants. although banned in several countries, the production has still not been discontinued, and thus hazards due to use or spill can be expected. the study reports on effects of the halone 1301 on three plant species frequently used for bioindication studies: lepidium sativum (mouse-ear cress), phaseolus vulgaris (bush bean) and petunia hybrida. plants were exposed to 1 ppbv of the gas in ambient air under controlled conditions for 18 days ... | 2000 | 11057687 |
| molecular characterisation of recq homologues in arabidopsis thaliana. | members of the recq family of dna helicases are involved in processes linked to dna replication, dna recombination and gene silencing. recq homologues of various animals have been described recently. here, for the first time for plants, we characterised cdnas of all in all six different recq-like proteins that are expressed to different extents in arabidopsis thaliana. surprisingly, three of these proteins are small in size [atrecql1, atrecql2, atrecql3-606, 705 and 713 amino acids (aa), respect ... | 2000 | 11058127 |
| identification of eukaryotic peptide deformylases reveals universality of n-terminal protein processing mechanisms. | the n-terminal protein processing pathway is an essential mechanism found in all organisms. however, it is widely believed that deformylase, a key enzyme involved in this process in bacteria, does not exist in eukaryotes, thus making it a target for antibacterial agents such as actinonin. in an attempt to define this process in higher eukaryotes we have used arabidopsis thaliana as a model organism. two deformylase cdnas, the first identified in any eukaryotic system, and six distinct methionine ... | 2000 | 11060042 |
| the arabidopsis thaliana isogene nit4 and its orthologs in tobacco encode beta-cyano-l-alanine hydratase/nitrilase. | nitrilases (nitrile aminohydrolases, ec ) are enzymes that catalyze the hydrolysis of nitriles to the corresponding carbon acids. among the four known nitrilases of arabidopsis thaliana, the isoform nit4 is the most divergent one, and homologs of nit4 are also known from species not belonging to the brassicaceae like nicotiana tabacum and oryza sativa. we expressed a. thaliana nit4 as hexahistidine tag fusion protein in escherichia coli. the purified enzyme showed a strong substrate specificity ... | 2001 | 11060302 |
| comparative analysis of tmv-cg and tmv-u1 detection methods in infected arabidopsis thaliana. | the common strain of the tobacco mosaic virus (tmv-u1), and the crucifer-infecting tobacco mosaic virus (tmv-cg), both members of tobamovirus genus, infect efficiently the solanaceous plants such as tomato and tobacco. the crucifer-infecting tobacco mosaic virus (tmv-cg) also infects arabidopsis thaliana plant, spreading systemically without causing severe symptoms. in contrast, arabidopsis is a poor host for tmv-u1 infection. within the past 10 years, arabidopsis has developed into a powerful m ... | 2000 | 11064114 |
| ccme, a nuclear-encoded heme-binding protein involved in cytochrome c maturation in plant mitochondria. | the maturation of c-type cytochromes requires the covalent attachment of the heme cofactor to the apoprotein. for this process, plant mitochondria follow a pathway distinct from that of animal or yeast mitochondria, closer to that found in alpha- and gamma-proteobacteria. we report the first characterization of a nuclear-encoded component, namely atccme, the arabidopsis thaliana orthologue of ccme, a periplasmic heme chaperone in bacteria. atccme is targeted to mitochondria, and its n-terminal s ... | 2001 | 11069919 |
| taube nuss is a novel gene essential for the survival of pluripotent cells of early mouse embryos. | the cells of the inner cell mass constitute the pluripotent cell population of the early embryo. they have the potential to form all of the tissues of the embryo proper and some extra-embryonic tissues. they can be considered a transient stem cell population for the whole of the embryo, and stem cells maintaining the same capacity can be isolated from these cells. we have isolated, characterised and mutated a novel gene, taube nuss (tbn), that is essential for the survival of this important cell ... | 2000 | 11076765 |
| structure and mechanism of activity of the cyclic phosphodiesterase of appr>p, a product of the trna splicing reaction. | the crystal structure of the cyclic phosphodiesterase (cpdase) from arabidopsis thaliana, an enzyme involved in the trna splicing pathway, was determined at 2.5 a resolution. cpdase hydrolyzes adp-ribose 1",2"-cyclic phosphate (appr>p), a product of the trna splicing reaction, to the monoester adp-ribose 1"-phosphate (appr-1"p). the 181 amino acid protein shows a novel, bilobal arrangement of two alphabeta modules. each lobe consists of two alpha-helices on the outer side of the molecule, framin ... | 2000 | 11080166 |
| evolution of the 14-3-3 protein family: does the large number of isoforms in multicellular organisms reflect functional specificity? | 14-3-3 proteins constitute a family of eukaryotic proteins that are key regulators of a large number of processes ranging from mitosis to apoptosis. 14-3-3s function as dimers and bind to particular motifs in their target proteins. to date, 14-3-3s have been implicated in regulation or stabilization of more than 35 different proteins. this number is probably only a fraction of the number of proteins that 14-3-3s bind to, as reports of new target proteins have become more frequent. an examination ... | 2000 | 11080367 |
| identification of two catalytic subunits of trna splicing endonuclease from arabidopsis thaliana. | trna splicing endonuclease is essential for the correct removal of introns from precursor trna molecules of archaea and eucarya. the only well-characterized eucaryotic enzyme until now is the endonuclease from yeast (saccharomyces cerevisiae). this protein has a heterotetrameric structure. two of the four subunits, i.e. sen34 and sen44, contain the active sites for cleavage at the 3'- and 5'-splice sites, respectively. we have identified three novel genes from arabidopsis thaliana, encoding puta ... | 2000 | 11080584 |
| genomic cloning and characterization of mitochondrial elongation factor tu (ef-tu) gene (tufm) from maize (zea mays l.). | we have cloned and characterized a mitochondrial elongation factor tu (ef-tu) gene (tufm) in maize (zea mays l.). this maize tufm gene encoded a polypeptide of 452 amino acid residues, consisting of a putative transit peptide of 55 residues and a mature ef-tu of 397 residues. the coding region was composed of 12 exons and 11 introns that ranged from 76 to 1673bp in length. the deduced amino acid sequence showed 85.9% and 61.2% identity with arabidopsis mitochondrial ef-tu and arabidopsis chlorop ... | 2000 | 11080589 |
| molecular cloning and functional characterization of cdnas encoding cysteine synthase and serine acetyltransferase that may be responsible for high cellular cysteine content in allium tuberosum. | the plants belonging to the genus allium are known to accumulate sulfur-containing secondary compounds that are derived from cysteine. here, we report on molecular cloning and functional characterization of two cdnas that encode serine acetyltransferase and cysteine synthase from a. tuberosum (chinese chive). the cdna for serine acetyltransferase encodes an open reading frame of 289 amino acids, of which expression could complement the lacking of cyse gene for endogenous serine acetyltransferase ... | 2000 | 11080593 |
| characterization of cax-like genes in plants: implications for functional diversity. | transporter-mediated ca(2+) efflux from the cytoplasm is an important component of plant signal transduction. to elucidate the diversity and role of ca(2+)/h(+) in controlling plant cytosolic ca(2+) concentrations, homologs of cax (for calcium exchanger) genes were cloned from zea mays and arabidopsis thaliana cdna libraries. the a. thaliana homolog of cax (athcx1) is 77% identical to cax1 while the z. mays homolog of cax (zmhcx1) is 64% identical to cax1 in amino acid sequence. athcx1 transcrip ... | 2000 | 11080595 |
| isolation and characterization of recombinant antibody fragments against cdc2a from arabidopsis thaliana. | in order to obtain recombinant antibody fragments that bind the cell-cycle protein cdc2a from arabidopsis thaliana (cdc2aat), two phage display libraries of single-chain variable (scfv) fragments were constructed. one library was derived from mice immunized with recombinant cdc2aat n-terminally fused to a his6-tag (his-cdc2aat) and the other was made out of an anti-pstaire hybridoma cell line. six specific his-cdc2aat-binding phage clones (3d1, 3d2, 3d10, 3d25, 4d21 and 4d47) were isolated by pa ... | 2000 | 11082187 |
| high-accuracy dna sequence variation screening by dhplc. | genetic maps based on biallelic single-nucleotide polymorphisms amenable to microarray-based genotyping have significantly accelerated the mapping of mono- and multigenic traits in model organisms such as saccharomyces cerevisiae and arabidopsis thaliana. this advance needs to be matched by highly accurate, inexpensive and robust methodology for fine-structure mapping of the candidate region(s) and the eventual identification of the causative mutation(s). to establish the usefulness of denaturin ... | 2000 | 11084871 |
| mutants of arabidopsis defective in a sequence-specific mrna degradation pathway. | one of the ways a cell can rapidly and tightly regulate gene expression is to target specific mrnas for rapid decay. a number of mrna instability sequences that mediate rapid mrna decay have been identified, particularly from multicellular eukaryotes, but pinpointing the cellular components that play critical roles in sequence-specific decay in vivo has been more difficult. in contrast, general pathways of mrna degradation in yeast have been well established through the analysis of mutants affec ... | 2000 | 11087822 |
| differential expression of four genes encoding 1-aminocyclopropane-1-caroboxylate synthase in lupinus albus during germination, and in response to indole-3-acetic acid and wounding. | 1-aminocyclopropane-1-carboxylate (acc) synthase (acs; ec 4.4.1.14) is the key regulatory enzyme of the ethylene biosynthetic pathway and is encoded by a multigene family in arabidopsis thaliana, tomato, mung bean and other plants. southern blot analysis revealed the existence of at least five acs genes in white lupin (lupinus albus l.) genome. four complete and one partial sequences representing different acs genes were cloned from the lupin genomic library. the levels of expression of two of t ... | 2000 | 11089679 |
| genes encoding nitrilase-like proteins from tobacco. | nitrilase (nitrile aminohydrolase, ec 3.5.5.1) catalyzes the hydrolysis of indole-3-acetonitrile (ian) to indole-3-acetic acid (iaa). arabidopsis thaliana genome has four nitrilase genes (nit1, nit2, nit3 and nit4). three (nit1, nit2 and nit3) of the four genes have high similarity. we have cloned two nit4 homologs (tnit4a and tnit4b) from tobacco (nicotiana tabacum). genomic southern hybridization, among other experiments, strongly suggests that tobacco has nit4 homologs but not nit1 to nit3 ho ... | 2000 | 11089910 |
| the late flowering phenotype of fwa mutants is caused by gain-of-function epigenetic alleles of a homeodomain gene. | the transition to flowering in arabidopsis thaliana is delayed in fwa mutant plants. fwa was identified by loss-of-function mutations in normally flowering revertants of the fwa mutant, and it encodes a homeodomain-containing transcription factor. the dna sequence of wild-type and fwa mutant alleles was identical in the genomic region of fwa. furthermore, the fwa gene is ectopically expressed in fwa mutants and silenced in mature wild-type plants. this silencing is associated with extensive meth ... | 2000 | 11090618 |
| automated sample-preparation technologies in genome sequencing projects. | a robotic workstation system (biorobot 96oo, qiagen) and a 96-well uv spectrophotometer (spectramax 250, molecular devices) were integrated in to the process of high-throughput automated sequencing of double-stranded plasmid dna templates. an automated 96-well miniprep kit protocol (qiaprep turbo, qiagen) provided high-quality plasmid dna from shotgun clones. the dna prepared by this procedure was used to generate more than two mega bases of final sequence data for two genomic projects (arabidop ... | 2000 | 11092729 |
| cdna cloning, expression and functional characterization of an arabidopsis thaliana homologue of the escherichia coli dna repair enzyme endonuclease iii. | reactive oxygen species (ros) are ubiquitous dna-damaging agents, and the repair of oxidative dna lesions is essential to prevent mutations and cell death. escherichia coli endonuclease iii is the prototype repair enzyme for removal of oxidized pyrimidines from dna. a database homology search identified a genomic sequence in arabidopsis thaliana encoding a predicted protein with sequence similarity to e. coli endonuclease iii. we cloned, sequenced and expressed the corresponding cdna, which enco ... | 2000 | 11094978 |
| overexpression of mitochondrial citrate synthase in arabidopsis thaliana improved growth on a phosphorus-limited soil. | the gene for mitochondrial citrate synthase (cs) was isolated from daucus carota (dccs) and introduced into arabidopsis thaliana (strain ws) using agrobacterium tumefaciens-mediated transformation. characteristics of citrate excretion were compared between t3 transgenic plants, which were derived from the initial transgenic plants by self-fertilization and homozygous for dccs, and the control plants that had no dccs. the highest cs activity 0.78 micromol protein min(-1) exhibited by the transgen ... | 2000 | 11100775 |
| are plant formins integral membrane proteins? | the formin family of proteins has been implicated in signaling pathways of cellular morphogenesis in both animals and fungi; in the latter case, at least, they participate in communication between the actin cytoskeleton and the cell surface. nevertheless, they appear to be cytoplasmic or nuclear proteins, and it is not clear whether they communicate with the plasma membrane, and if so, how. because nothing is known about formin function in plants, i performed a systematic search for putative ara ... | 2000 | 11104517 |
| rbp45 and rbp47, two oligouridylate-specific hnrnp-like proteins interacting with poly(a)+ rna in nuclei of plant cells. | introns in plant nuclear pre-mrnas are highly enriched in u or u + a residues and this property is essential for efficient splicing. moreover, 3'-untranslated regions (3'-utrs) in plant pre-mrnas are generally ua-rich and contain sequences that are important for the polyadenylation reaction. here, we characterize two structurally related rna-binding proteins (rbps) from nicotiana plumbaginifolia, referred to as rbp45 and rbp47, having specificity for oligouridylates. both proteins contain three ... | 2000 | 11105760 |
| the pseudomonas syringae avrrpt2 gene product promotes pathogen virulence from inside plant cells. | several bacterial avr genes have been shown to contribute to virulence on susceptible plants lacking the corresponding resistance (r) gene. the mechanisms by which avr genes promote parasitism and disease, however, are not well understood. we investigated the role of the pseudomonas syringae pv. tomato avrrpt2 gene in pathogenesis by studying the interaction of p. syringae pv. tomato strain pstdc3000 expressing avrrpt2 with several arabidopsis thaliana lines lacking the corresponding r gene, rps ... | 2000 | 11106023 |
| novel features of the xrn-family in arabidopsis: evidence that atxrn4, one of several orthologs of nuclear xrn2p/rat1p, functions in the cytoplasm. | the 5'-3' exoribonucleases xrn1p and xrn2p/rat1p function in the degradation and processing of several classes of rna in saccharomyces cerevisiae. xrn1p is the main enzyme catalyzing cytoplasmic mrna degradation in multiple decay pathways, whereas xrn2p/rat1p functions in the processing of rrnas and small nucleolar rnas (snornas) in the nucleus. much less is known about the xrn-like proteins of multicellular eukaryotes; however, differences in their activities could explain differences in mrna d ... | 2000 | 11106401 |
| evidence for two distinct effector-binding sites in threonine deaminase by site-directed mutagenesis, kinetic, and binding experiments. | a three-dimensional structure comparison between the dimeric regulatory serine-binding domain of escherichia coli d-3-phosphoglycerate dehydrogenase [schuller, d. j., grant, g. a., and banaszak, l. j. (1995) nat. struct. biol. 2, 69-76] and the regulatory domain of e. coli threonine deaminase [gallagher, d. t., gilliland, g. l., xiao, g., zondlo, j., fisher, k. e., chinchilla, d. , and eisenstein, e. (1998) structure 6, 465-475] led us to make the hypothesis that threonine deaminase could have t ... | 2000 | 11106492 |
| cloning and characterization of a putative human glycerol 3-phosphate permease gene (slc37a1 or g3pp) on 21q22.3: mutation analysis in two candidate phenotypes, dfnb10 and a glycerol kinase deficiency. | using multiple exons trapped from human chromosome 21 (hc21)-specific cosmids with homology to a putative arabidopsis thaliana glycerol 3-phosphate permease, we have determined the full-length cdna sequence of a novel hc21 gene encoding a putative sugar-phosphate transporter (hgmw-approved symbol slc37a1, aka g3pp). the predicted protein has 12 putative transmembrane domains and is also highly homologous to bacterial glpt proteins. the transcript was precisely mapped to 21q22.3 between d21s49 an ... | 2000 | 11112347 |
| an alternative cytokinin biosynthesis pathway. | studies of de novo cytokinin biosynthesis in isopentenyltransferase (ipt)-transformed arabidopsis thaliana, involving in vivo deuterium labeling and mass spectrometry, showed that the biosynthetic rate of zeatinriboside-5'-monophosphate was around 66-fold higher than that of isopentenyladenosine-5'-monophosphate (ipmp), the proposed primary product of the agrobacterium ipt. double tracer analysis, using [(2)h(6)] isopentenyladenosine and deuterium oxide, provided evidence for an alternative, ipm ... | 2000 | 11114204 |
| a member of a novel arabidopsis thaliana gene family of candidate mg2+ ion transporters complements a yeast mitochondrial group ii intron-splicing mutant. | autocatalytic activity of some group ii introns has been demonstrated in vitro, but helper functions such as the yeast mrs2 protein are essential for splicing in vivo. in our search for such helper factors in plants, we pursued the cloning of two arabidopsis thaliana homologues, atmrs2-1 and atmrs2-2. atmrs2-1, but not atmrs2-2, complements the yeast deletion mutant of mrs2, and this is congruent with the prediction of two adjacent transmembrane stretches in atmrs2-1 and yeast mrs2 but not in at ... | 2000 | 11115130 |
| enhanced multispecificity of arabidopsis vacuolar multidrug resistance-associated protein-type atp-binding cassette transporter, atmrp2. | recent investigations have established that arabidopsis thaliana contains a family of genes encoding atp-binding cassette transporters belonging to the multidrug resistance-associated protein (mrp) family. so named because of the phenotypes conferred by their animal prototypes, many mrps are mgatp-energized pumps active in the transport of glutathione (gs) conjugates and other bulky amphipathic anions across membranes. here we show that arabidopsis mrp2 (atmrp2) localizes to the vacuolar membran ... | 2001 | 11115509 |
| functional analysis of a rpd3 histone deacetylase homologue in arabidopsis thaliana. | histone acetylation is modulated through the action of histone acetyltransferase and deacetylase, which play key roles in the regulation of eukaryotic gene expression. we have screened the expressed sequence tag database with the yeast histone deacetylase rpd3 sequence and identified two arabidopsis homologues, atrpd3a and atrpd3b. the deduced amino acid sequences of atrpd3a and atrpd3b show high overall homology (55% identity) to each other. atrpd3a encodes a putative protein of 502 amino acids ... | 2000 | 11117260 |
| arabidopsis transcription factors: genome-wide comparative analysis among eukaryotes. | the completion of the arabidopsis thaliana genome sequence allows a comparative analysis of transcriptional regulators across the three eukaryotic kingdoms. arabidopsis dedicates over 5% of its genome to code for more than 1500 transcription factors, about 45% of which are from families specific to plants. arabidopsis transcription factors that belong to families common to all eukaryotes do not share significant similarity with those of the other kingdoms beyond the conserved dna binding domains ... | 2000 | 11118137 |
| functional conservation of phosphorylation-specific prolyl isomerases in plants. | the phosphorylation-specific peptidyl prolyl cis/trans isomerase (ppiase) pin1 in humans and its homologues in yeast and animal species play an important role in cell cycle regulation. these ppiases consist of an nh(2)-terminal ww domain that binds to specific phosphoserine- or phosphothreonine-proline motifs present in a subset of phosphoproteins and a cooh-terminal ppiase domain that specifically isomerizes the phosphorylated serine/threonine-proline peptide bonds. here, we describe the isolat ... | 2001 | 11118438 |
| rice salt promoter is activated in papaver somniferum and nicotiana tabacum transgenic cells in the absence of exogenous aba. | with the aim of modifying secondary metabolism in opium poppy (papaver somniferum) and tobacco (nicotiana tabacum) cells, gene transfer was performed using the sam1 gene from arabidopsis thaliana under the control of the salt promoter. this promoter is induced by aba in rice and in tobacco and we have shown that it is also induced in poppy cells (gus gene). putatively transformed poppy and tobacco cell lines with the sam1 gene were obtained. in the absence of exogenous inducer we noticed the exp ... | 2001 | 11118604 |