| effects of weightlessness on photosynthesizing cells structure of plant. | it was established early that the signs of accelerated aging of both plant leaves and of moss chloronema were observed in seedlings of high plants and in funaria hygrometrica protonema under long term growing under weightlessness. it was observed the structure changing of photosynthesizing cells in arabidopsis thaliana, epidendrum radicans and pisum sativum leaves. authors found out the extension and vesiculation of thylakoids between chloroplast granas. they observed thylakoids partly destroyin ... | 1997 | 11540707 |
| biological investigations aboard the biosatellite cosmos-1129. | experiments on insects, higher plants and lower fungi were carried out aboard the biological satellite cosmos-l129, in earth orbit, from 25 september to 14 october 1979. the main objective of these experiments was to gain more profound knowledge of the effect of weightlessness on living organisms and to study the mechanisms by which these various organisms with different life cycles can adjust and develop in weightlessness. experiments on insects (drosophila melanogaster) were made with a view t ... | 1981 | 11541724 |
| genomic analysis of synaptotagmin genes. | i used tblastn to probe dna sequence databases with a consensus peptide sequence corresponding to the most highly conserved region of the rodent synaptotagmin (syt) gene family, which is within the c2b domain. i found human homologues for all known rodent genes, and found six further human genomic loci which encode potential family members. i found eight potential family members in caenorhabditis elegans, six in drosophila melanogaster, and four in arabidopsis thaliana. the c. elegans syt1 homol ... | 2001 | 11543631 |
| functional analysis of the arabidopsis thaliana mismatch repair gene msh2. | the arabidopsis thaliana msh2 (atmsh2) gene encodes a protein that belongs to a family of highly conserved proteins (muts homologues (msh)) involved in dna mismatch repair. sequence analysis strongly suggests that this single copy gene is indeed a homologue of msh2, a gene known to play a central role in eukaryotic mismatch repair. in this report, we show that the atmsh2 protein has functional attributes characteristic of previously described mismatch repair proteins. first, over-expression of t ... | 2001 | 11550901 |
| differential activity and structure of highly similar peroxidases. spectroscopic, crystallographic, and enzymatic analyses of lignifying arabidopsis thaliana peroxidase a2 and horseradish peroxidase a2. | anionic arabidopsis thaliana peroxidase atp a2 was expressed in escherichia coli and used as a model for the 95% identical commercially available horseradish peroxidase hrp a2. the crystal structure of atp a2 at 1.45 a resolution at 100 k showed a water molecule only 2.1 a from heme iron [ostergaard, l., et al. (2000) plant mol. biol. 44, 231-243], whereas spectroscopic studies of hrp a2 in solution at room temperature [feis, a., et al. (1998) j. raman spectrosc. 29, 933-938] showed five-coordin ... | 2001 | 11551197 |
| the large subunit of the mammalian mitochondrial ribosome. analysis of the complement of ribosomal proteins present. | identification of all the protein components of the large subunit (39 s) of the mammalian mitochondrial ribosome has been achieved by carrying out proteolytic digestions of whole 39 s subunits followed by analysis of the resultant peptides by liquid chromatography and mass spectrometry. peptide sequence information was used to search the human est data bases and complete coding sequences were assembled. the human mitochondrial 39 s subunit has 48 distinct proteins. twenty eight of these are homo ... | 2001 | 11551941 |
| plant adenosine 5'-phosphosulfate reductase is a novel iron-sulfur protein. | adenosine 5'-phosphosulfate reductase (apr) catalyzes the two-electron reduction of adenosine 5'-phosphosulfate to sulfite and amp, which represents the key step of sulfate assimilation in higher plants. recombinant aprs from both lemna minor and arabidopsis thaliana were overexpressed in escherichia coli and isolated as yellow-brown proteins. uv-visible spectra of these recombinant proteins indicated the presence of iron-sulfur centers, whereas flavin was absent. this result was confirmed by qu ... | 2001 | 11553635 |
| two types of mgdg synthase genes, found widely in both 16:3 and 18:3 plants, differentially mediate galactolipid syntheses in photosynthetic and nonphotosynthetic tissues in arabidopsis thaliana. | in arabidopsis, monogalactosyldiacylglycerol (mgdg) is synthesized by a multigenic family of mgdg synthases consisting of two types of enzymes differing in their n-terminal portion: type a (atmgd1) and type b (atmgd2 and atmgd3). the present paper compares type b isoforms with the enzymes of type a that are known to sit in the inner membrane of plastid envelope. the occurrence of types a and b in 16:3 and 18:3 plants shows that both types are not specialized isoforms for the prokaryotic and euka ... | 2001 | 11553816 |
| beta-d-glycan synthases and the cesa gene family: lessons to be learned from the mixed-linkage (1-->3),(1-->4)beta-d-glucan synthase. | cellulose synthase genes (cesas) encode a broad range of processive glycosyltransferases that synthesize (1-->4)beta-d-glycosyl units. the proteins predicted to be encoded by these genes contain up to eight membrane-spanning domains and four 'u-motifs' with conserved aspartate residues and a qxxrw motif that are essential for substrate binding and catalysis. in higher plants, the domain structure includes two plant-specific regions, one that is relatively conserved and a second, so-called 'hyper ... | 2001 | 11554469 |
| chloroplast targeting of chloroplast division ftsz2 proteins in arabidopsis. | plant nuclear genomes encode chloroplast division proteins homologous to the eubacterial cell division protein ftsz. in higher plants, ftsz genes constitute a small gene family that consists of two subgroups, ftsz1 and ftsz2. it was previously hypothesized that members of one family (ftsz1) targeted chloroplasts, while members of the other family (ftsz2) localized in the cytoplasm. we determined the full-length cdna sequences of two ftsz2 genes from arabidopsis thaliana (atftsz2-1 and atftsz2-2) ... | 2001 | 11554751 |
| crystal structures of human gephyrin and plant cnx1 g domains: comparative analysis and functional implications. | the molybdenum cofactor (moco) consists of a unique and conserved pterin derivative, usually referred to as molybdopterin (mpt), which coordinates the essential transition metal molybdenum (mo). moco is required for the enzymatic activities of all mo-enzymes, with the exception of nitrogenase and is synthesized by an evolutionary old multi-step pathway that is dependent on the activities of at least six gene products. in eukaryotes, the final step of moco biosynthesis, i.e. transfer and insertio ... | 2001 | 11554796 |
| type iii secretion in plant growth-promoting pseudomonas fluorescens sbw25. | in vivo expression technology (ivet) analysis of rhizosphere-induced genes in the plant growth-promoting rhizobacterium (pgpr) pseudomonas fluorescens sbw25 identified a homologue of the type iii secretion system (ttss) gene hrcc. the hrcc homologue resides within a 20-kb gene cluster that resembles the type iii (hrp) gene cluster of pseudomonas syringae. the type iii (rsp) gene cluster in p. fluorescens sbw25 is flanked by a homologue of the p. syringae ttss-secreted protein avre. p. fluorescen ... | 2001 | 11555282 |
| the roles of mucd and alginate in the virulence of pseudomonas aeruginosa in plants, nematodes and mice. | we are exploiting the broad host range of the human opportunistic pathogen pseudomonas aeruginosa strain pa14 to elucidate the molecular basis of bacterial virulence in plants, nematodes, insects and mice. in this report, we characterize the role that two pa14 gene products, mucd and algd, play in virulence. mucd is orthologous to the escherichia coli periplasmic protease and chaperone degp. degp homologues are known virulence factors that play a protective role in stress responses in various sp ... | 2001 | 11555287 |
| toxicological relevance of the multidrug resistance protein 1, mrp1 (abcc1) and related transporters. | the 190 kda multidrug resistance protein 1 (mrp1/abcc1) is a founding member of a subfamily of the atp binding cassette (abc) superfamily of transport proteins and was originally identified on the basis of its elevated expression in multidrug resistant lung cancer cells. in addition to its ability to confer resistance in tumour cells, mrp1 is ubiquitously expressed in normal tissues and is a primary active transporter of gsh, glucuronate and sulfate conjugated and unconjugated organic anions of ... | 2001 | 11557126 |
| lignification induced by pseudomonads harboring avirulent genes on arabidopsis. | the responses of arabidopsis thaliana ecotypes to the bacterial pathogen pseudomonas syringae pv. maculicola 4326 (psm4326) harboring cloned avirulence genes avrb and avrrpt2 from p. syringae pv. glycinea were examined. psm4326 containing avirulent genes, avrb and avrrpt2 induced lignification and peroxidase activities in the bacteria infiltrated leaves of col-o only and not in mt-o, bla-2 and po-1. however, arabidopsis ecotypes infiltrated with psm4326 harboring with and without avirulent genes ... | 2001 | 11561727 |
| the tomato mosaic tobamovirus movement protein interacts with a putative transcriptional coactivator kelp. | viral movement through plasmodesmata in host plants likely depends on the interaction between virus-encoded movement protein (mp) and host proteins. in order to search for mp-interacting protein (mip), we carried out far-western screening of a brassica campestris cdna library using a recombinant mp of tomato mosaic tobamovirus (tomv) as a probe. one of the positive clones, designated mip102, was found to be a putative orthologue for a transcriptional coactivator kelp of arabidopsis thaliana. in ... | 2001 | 11561731 |
| structural determinants of ca2+ transport in the arabidopsis h+/ca2+ antiporter cax1. | ca(2+) levels in plants, fungi, and bacteria are controlled in part by h(+)/ca(2+) exchangers; however, the relationship between primary sequence and biological activity of these transporters has not been reported. the arabidopsis h(+)/cation exchangers, cax1 and cax2, were identified by their ability to suppress yeast mutants defective in vacuolar ca(2+) transport. cax1 has a much higher capacity for ca(2+) transport than cax2. an arabidopsis thaliana homolog of cax1, cax3, is 77% identical (93 ... | 2001 | 11562366 |
| putative dna-(amino)methyltransferases in eucaryotes. | by computer analysis of the known data bases, we have established that the open reading frames (orf) coding for proteins that possess high degree of homology with procaryotic dna-(amino)methyltransferases are present in the genomes of leishmania major, saccharomyces cerevisiae, schizosaccharomyces pombe, arabidopsis thaliana, drosophila melanogaster, caenorhabditis elegans, and homo sapiens. conservative motifs typical for bacterial dna-(amino)methyltransferases are detected in the amino acid se ... | 2001 | 11563955 |
| functional reconstitution of arabidopsis thaliana plant uncoupling mitochondrial protein (atpump1) expressed in escherichia coli. | the arabidopsis thaliana uncoupling protein (ucp) gene was expressed in escherichia coli and isolated protein reconstituted into liposomes. linoleic acid-induced h+ fluxes were sensitive to purine nucleotide inhibition with an apparent k(i) (in mm) of 0.8 (gdp), 0.85 (atp), 0.98 (gtp), and 1.41 (adp); the inhibition was ph-dependent. kinetics of atpump1-mediated h+ fluxes were determined for lauric, myristic, palmitic, oleic, linoleic, and linolenic acids. properties of recombinant atpump1 indic ... | 2001 | 11566183 |
| identification of a monofunctional aspartate kinase gene of arabidopsis thaliana with spatially and temporally regulated expression. | we screened a gene trap library of arabidopsis thaliana and isolated a line in which a gene encoding a homologue of monofunctional aspartate kinase was trapped by the reporter gene. aspartate kinase (ak) is a key enzyme in the biosynthsis of aspartate family amino acids such as lysine, threonine, isoleucine, and methionine. in plants, two types of ak are known: one is ak which is sensitive to feedback inhibition by threonine and carries both ak and homoserine dehydrogenase (hsd) activities. the ... | 2001 | 11569502 |
| dual targeting properties of the n-terminal signal sequence of arabidopsis thaliana thi1 protein to mitochondria and chloroplasts. | thi1 has been recently isolated from arabidopsis thaliana and is probably involved in both thiamine biosynthesis and as protection of organellar dna from damage. studies of thiamine biosynthesis in plants suggests a plastid location for the pathway, which is in agreement with the predicted thi1 n-terminal chloroplastic transit peptide (tp). on the other hand, thiamine is synthesized in mitochondria in yeast cells. interestingly, a. thaliana thi1 cdna complements a yeast strain disrupted for the ... | 2001 | 11575719 |
| cdna cloning of two isoforms of ornithine carbamoyltransferase from canavalia lineata leaves and the effect of site-directed mutagenesis of the carbamoyl phosphate binding site. | the immunoscreening method was used to isolate cdnas of 1323 bp (cloct1) and 1433 bp (cloct2) encoding two ornithine carbamoyltransferases (oct, ec 2.1.3.3) from the cdna expression library of canavalia lineata leaves constructed in a lambdazap express vector. cloct1 and cloct2 encode 359 and 369 amino acids, respectively. the n-terminals of deduced amino acid sequences of the two cdnas showed typical features of the transit peptide of chloroplast targeting proteins. the ornithine-binding domain ... | 2001 | 11575720 |
| establishment of arabidopsis thaliana ribosomal protein rpl23a-1 as a functional homologue of saccharomyces cerevisiae ribosomal protein l25. | arabidopsis thaliana ribosomal protein (r-protein) rpl23a-1 shows 54% amino acid sequence identity to the saccharomyces cerevisiae equivalent r-protein, l25. atrpl23a-1 also shows high amino acid sequence identity to members of the l23/l25 r-protein family in other species. r-protein l25 in s. cerevisiae has been identified as a primary rrna-binding protein that directly binds to a specific site on yeast 26s rrna. it is translocated to the nucleolus where it binds to 26s rrna during early large ... | 2001 | 11575722 |
| a library of arabidopsis 35s-cdna lines for identifying novel mutants. | we have developed a system to over-express or co-suppress random cdnas in arabidopsis thaliana upon agrobacterium tumefaciens-mediated transformation. we constructed a binary vector containing a novel arabidopsis cdna library driven by the cauliflower mosaic virus (camv) 35s promoter. the vector, 35spbarn, offers in terra selection with glufosinate ammonium (basta) and the ability to identify the cdna insert using pcr with flanking primers. we introduced this overexpression library into arabidop ... | 2001 | 11575724 |
| tissue-specific and developmental-specific expression of an arabidopsis thaliana gene encoding the lipoamide dehydrogenase component of the plastid pyruvate dehydrogenase complex. | we describe an arabidopsis thaliana gene, ptlpd2, which codes for a protein with high amino acid similarity to lipoamide dehydrogenases (lpds) from diverse species. ptlpd2 codes for a precursor protein possessing an n-terminal extension predicted to be a plastid-targeting signal. expression of the ptlpd2 cdna in escherichia coli showed the encoded protein possessed the predicted lpd activity. ptlpd2 protein, synthesized in vitro, was efficiently imported into isolated chloroplasts of pisum sativ ... | 2001 | 11575725 |
| the ubiquitin-specific protease ubp14 is essential for early embryo development in arabidopsis thaliana. | the ubiquitin/26s proteasome pathway is a major route for selectively degrading cytoplasmic and nuclear proteins in eukaryotes. in this pathway, chains of ubiquitins become attached to short-lived proteins, signalling recognition and breakdown of the modified protein by the 26s proteasome. during or following target degradation, the attached multi-ubiquitin chains are released and subsequently disassembled by ubiquitin-specific proteases (ubps) to regenerate free ubiquitin monomers for re-use. h ... | 2001 | 11576424 |
| subcellular localization and targeting of glucocorticoid receptor protein fusions expressed in transgenic arabidopsis thaliana. | an animal system of inducible activation of protein fusions with the binding domain of glucocorticoid receptor (bdgr) was tested in arabidopsis thaliana by monitoring dexamethasone (dex)-induced nuclear targeting of reporter constructs. two constructs containing green fluorescent protein (gfp), human homeobox protein hanf-1 and xenopus laevis bdgr were used, gfp/hanf-1/bdgr and gfp/bdgr. the control construct contained gfp alone. in the absence of dex both fusion proteins were uniformly distribu ... | 2001 | 11577188 |
| an arabidopsis snf1-related protein kinase, atsr1, interacts with a calcium-binding protein, atcbl2, of which transcripts respond to light. | atsr1 is a protein kinase of arabidopsis thaliana, which belongs to the snf1-related protein kinase subfamily 3. we previously showed accumulation of its transcripts to be responsive to light. in this study, we examined the interaction between atsr1 and six calcineurin b like proteins of arabidopsis and found that atsr1 prominently interacts with one of them, atcbl2, by yeast two-hybrid assay. interaction between atsr1 and atcbl2 could also be directly confirmed in vitro by pull down assay. rna ... | 2001 | 11577192 |
| the arabidopsis ahk4 histidine kinase is a cytokinin-binding receptor that transduces cytokinin signals across the membrane. | common histidine-to-aspartate (his-->asp) phosphorelay is a paradigm of signal transduction in both prokaryotes and eukaryotes for the propagation of certain environmental stimuli, in which histidine (his)-kinases play central roles as sensors for environmental signals. for the higher plant, arabidopsis thaliana, it was recently suggested that the his-kinase (ahk4 / cre1 / wol) is a sensor for cytokinins, which are a class of plant hormones important for the regulation of cell division and diffe ... | 2001 | 11577198 |
| temporal and spatial expression patterns of tub9, a beta-tubulin gene of arabidopsis thaliana. | transgenic plants carrying chimeric genes composed of segments of the 5'-flanking region of the arabidopsis 9-tubulin gene (tub9) fused to the coding region of the beta-glucuronidase (gus) gene of escherichia coli were used to investigate the temporal and spatial patterns of tub9 expression. chimeric genes that contained at least 800 bp of tub9 5'-flanking dna were expressed primarily in floral tissues, with high levels of expression observed in pollen, elongating pollen tubes and ovules. the ex ... | 2001 | 11587510 |
| the pub domain: a putative protein-protein interaction domain implicated in the ubiquitin-proteasome pathway. | cytoplasmic peptide:n-glycanase (pngase) is a de-n-glycosylating enzyme which may be involved in the proteasome-dependent pathway for degradation of misfolded glycoproteins formed in the endoplasmic reticulum (er) that are exported into the cytoplasm. a cytoplasmic pngase found in saccharomyces cerevisiae, png1p, is widely distributed in higher eukaryotes as well as in yeast (suzuki, t., et al. j. cell biol. 149, 1039-1051, 2000). the recently uncovered complete genome sequence of arabidopsis th ... | 2001 | 11587532 |
| contribution of sponge genes to unravel the genome of the hypothetical ancestor of metazoa (urmetazoa). | recently the term urmetazoa, as the hypothetical metazoan ancestor, was introduced to highlight the finding that all metazoan phyla including the porifera (sponges) are derived from one common ancestor. sponges as the evolutionarily oldest, still extant phylum, are provided with a complex network of structural and functional molecules. analyses of sponge genomes from demospongiae (suberites domuncula and geodia cydonium), calcarea (sycon raphanus) and hexactinellida (aphrocallistes vastus) have ... | 2001 | 11591483 |
| identification and biochemical characterization of arabidopsis thaliana sulfite oxidase. a new player in plant sulfur metabolism. | in mammals and birds, sulfite oxidase (so) is a homodimeric molybdenum enzyme consisting of an n-terminal heme domain and a c-terminal molybdenum domain (ec ). in plants, the existence of so has not yet been demonstrated, while sulfite reductase as part of sulfur assimilation is well characterized. here we report the cloning of a plant sulfite oxidase gene from arabidopsis thaliana and the biochemical characterization of the encoded protein (at-so). at-so is a molybdenum enzyme with molybdopteri ... | 2001 | 11598126 |
| adaptins: the final recount. | adaptins are subunits of adaptor protein (ap) complexes involved in the formation of intracellular transport vesicles and in the selection of cargo for incorporation into the vesicles. in this article, we report the results of a survey for adaptins from sequenced genomes including those of man, mouse, the fruit fly drosophila melanogaster, the nematode caenorhabditis elegans, the plant arabidopsis thaliana, and the yeasts, saccharomyces cerevisiae and schizosaccharomyces pombe. we find that huma ... | 2001 | 11598180 |
| genomic analysis of the hsp70 superfamily in arabidopsis thaliana. | the arabidopsis genome contains at least 18 genes encoding members of the 70-kilodalton heat shock protein (hsp70) family, 14 in the dnak subfamily and 4 in the hsp110/sse subfamily. while the hsp70s are highly conserved, a phylogenetic analysis including all members of this family in arabidopsis and in yeast indicates the homology of hsp70s in the subgroups, such as those predicted to localize in the same subcellular compartment and those similar to the mammalian hsp110 and grp170. gene structu ... | 2001 | 11599561 |
| arabidopsis thaliana hsp100 proteins: kith and kin. | arabidopsis thaliana, the first plant for which the entire genome sequence is available, was also among the first plant species from which hsp100 proteins were characterized. the athsp101 complementary dna (cdna) corresponds to the gene identification at1g74310 in the arabidopsis genome sequence. analysis of the genome revealed 7 additional proteins that are variably homologous with at1g74310 throughout the entire amino acid sequence and significant similarities or identities in the signature se ... | 2001 | 11599563 |
| the hsp90 family of proteins in arabidopsis thaliana. | the 90-kda heat shock protein (hsp90) is an essential molecular chaperone in eukaryotic cells, with key roles in the folding and activation of proteins involved in signal transduction and control of the cell cycle. a search for hsp90 sequences in the arabidopsis thaliana genome revealed that this family includes 7 members. the athsp90-1 through athsp90-4 proteins constitute the cytoplasmic subfamily, whereas the athsp90-5, athsp90-6, and athsp90-7 proteins are predicted to be within the plastidi ... | 2001 | 11599565 |
| orthologs in arabidopsis thaliana of the hsp70 interacting protein hip. | the hsp70-interacting protein hip binds to the adenosine triphosphatase domain of hsp70, stabilizing it in the adenosine 5'-diphosphate-ligated conformation and promoting binding of target polypeptides. in mammalian cells, hip is a component of the cytoplasmic chaperone heterocomplex that regulates signal transduction via interaction with hormone receptors and protein kinases. analysis of the complete genome sequence of the model flowering plant arabidopsis thaliana revealed 2 genes encoding hip ... | 2001 | 11599566 |
| in vivo and in vitro characterization of an rna replication enhancer in a satellite rna associated with turnip crinkle virus. | rna replication enhancers are cis-acting elements that can stimulate replication or transcription of rna viruses. turnip crinkle virus (tcv) and satc, a parasitic rna associated with tcv infections, contain stem-loop structures that are rna replication enhancers (p. nagy, j. pogany, and a. e. simon, embo j. 1999, 18, 5653-5665). we have found that replacement of 28 nt of the satc enhancer, termed the motif1-hairpin, with 28 randomized bases reduced satc accumulation 8- to 13-fold in arabidopsis ... | 2001 | 11601903 |
| identification of an arabidopsis cdna encoding a lipoyltransferase located in plastids. | in plant cells, the pyruvate dehydrogenase (pdh) complex that requires lipoic acid as an essential coenzyme is located in plastids and mitochondria. the enzyme complex has to be lipoylated in both organelles. however, the lipoyltransferase located in plastids has not been reported. in this study, an arabidopsis thaliana lip2p cdna for a lipoyltransferase located in plastids has been identified. we have shown that this cdna encodes a lipoyltransferase by demonstrating its ability to complement an ... | 2001 | 11602263 |
| salicylic acid and nim1/npr1-independent gene induction by incompatible peronospora parasitica in arabidopsis. | to identify pathogen-induced genes distinct from those involved in systemic acquired resistance, we used cdna-amplified fragment length polymorphism to examine rna levels in arabidopsis thaliana wild type, nim1-1, and salicylate hydroxylase-expressing plants after inoculation with an incompatible isolate of the downy mildew pathogen peronospora parasitica. fifteen genes are described, which define three response profiles on the basis of whether their induction requires salicylic acid (sa) accumu ... | 2001 | 11605963 |
| ndr1, a locus of arabidopsis thaliana that is required for disease resistance to both a bacterial and a fungal pathogen. | we have employed arabidopsis thaliana as a model host plant to genetically dissect the molecular pathways leading to disease resistance. a. thaliana accession col-0 is susceptible to the bacterial pathogen pseudomonas syringae pv. tomato strain dc3000 but resistant in a race-specific manner to dc3000 carrying any one of the cloned avirulence genes avrb, avrrpm1, avrrpt2, and avrpph3. fast-neutron-mutagenized col-0 m2 seed was screened to identify mutants susceptible to dc3000(avrb). disease assa ... | 1995 | 11607554 |
| [creation of a collection of morphological insertional mutants of arabidopsis thaliana]. | a collection of transgenic arabidopsis thaliana plants has been obtained by agrobacterium-mediated transformation. the genomes of the transgenic plants contain insertions of t-dna of the vector plasmids pld3 or ppcvrn4. genes bearing t-dna insertions were shown to constitute 12-18% of the total number of a. thaliana genes. seventy-five lines have been chosen from the collection and subjected to genetic and molecular-genetic analysis. of these, 5 were dominant mutants, and 70, recessive insertion ... | 2001 | 11642108 |
| n-terminal truncation affects the kinetics and structure of fructose-6-phosphate 2-kinase/fructose-2,6-bisphosphatase from arabidopsis thaliana. | the enzyme fructose-6-phosphate 2-kinase (f6p,2k; 6-phosphofructo-2-kinase)/fructose-2,6-bisphosphatase (f26bpase) catalyses the formation and degradation of the regulatory metabolite fructose 2,6-bisphosphate. a cdna encoding the bifunctional plant enzyme isolated from arabidopsis thaliana (atf2kp) was expressed in yeast, and the substrate affinities and allosteric properties of the affinity-purified enzyme were characterized. in addition to the known regulators 3-phosphoglycerate, dihydroxyace ... | 2001 | 11672433 |
| a mads box gene from lily (lilium longiflorum) is sufficient to generate dominant negative mutation by interacting with pistillata (pi) in arabidopsis thaliana. | lily mads box gene 1 (lmads1), with sequence homology to the ap3 family of genes, was cloned and characterized from lily (lilium longiflorum). lmads1 protein contains almost complete consensus sequence of the pistillata (pi)-derived motif (yefrvqpsqpnlh) found in the ap3 family of genes and paleoap3 motif (ygshdlrla) found in the ap3 family of genes from the low eudicot, magnolid dicot and monocot species. lmads1 mrna was expressed in all four whorls of the flower and absent in the vegetative le ... | 2001 | 11673632 |
| a senescence-associated s-like rnase in the multicellular green alga volvox carteri. | asexual individuals of the green alga volvox carteri consist of only two cell types: somatic and reproductive cells. the somatic cells are terminally differentiated, post-mitotic cells which undergo gradual senescence leading to cell death in every generation. to elucidate the self-degrading process of macromolecules associated with senescence, we attempted to clone an rnase whose mrna accumulation is increased during senescence. the corresponding cdna clone vrn1, encoding an s-like rnase of v. ... | 2001 | 11675015 |
| mass spectrometry allows direct identification of proteins in large genomes. | proteome projects seek to provide systematic functional analysis of the genes uncovered by genome sequencing initiatives. mass spectrometric protein identification is a key requirement in these studies but to date, database searching tools rely on the availability of protein sequences derived from full length cdna, expressed sequence tags or predicted open reading frames (orfs) from genomic sequences. we demonstrate here that proteins can be identified directly in large genomic databases using p ... | 2001 | 11678034 |
| a specific brassinosteroid biosynthesis inhibitor, brz2001: evaluation of its effects on arabidopsis, cress, tobacco, and rice. | brassinazole is the only known specific brassinosteroid (br)-biosynthesis inhibitor, and it has been shown to be useful for elucidating the function of brs. in the course of a structure-activity relationship study of brassinazole, we found a more specific br-biosynthesis inhibitor, brz2001. this new inhibitor induced similar morphological changes to those seen in brassinazole-treated plants, including arabidopsis thaliana (l.) heynh., nicotiana tabacum l., and lepidium sativum l. these changes i ... | 2001 | 11678275 |
| kin241: a gene involved in cell morphogenesis in paramecium tetraurelia reveals a novel protein family of cyclophilin-rna interacting proteins (crips) conserved from fission yeast to man. | in this study, we report cloning, by functional complementation of the kin241 gene involved in paramecium cell morphogenesis, cortical organization and nuclear reorganization. this gene is predicted to encode a protein of a novel type, comprising a cyclophilin-type, peptidyl-prolyl isomerase domain, an rna recognition motif, followed by a region rich in glutamate and lysine (ek domain) and a c-terminal string of serines. as homologues of this protein are present in the genomes of schizosaccharom ... | 2001 | 11679083 |
| identification of genes expressed in response to light stress in leaves of arabidopsis thaliana using rna differential display. | the plant cell responds to light stress by the expression of genes encoding specific stress proteins with possible protective functions. five genes, the mrna levels of which increased drastically in response to light stress in mature green leaves of arabidopsis thaliana were identified and isolated by the differential display technique. these genes were designated lsr1-lsr5 (light stress-regulated). northern blot analysis demonstrated that the transcript level of lsr1-lsr5 increased 4- to 17-fol ... | 2001 | 11683875 |
| arabidopsis thaliana expresses a second functional phytochelatin synthase. | phytochelatins represent a major detoxifying pathway for heavy metals in plants and many other organisms. the arabidopsis thaliana cad1 (=atpcs1) gene encodes a phytochelatin synthase and cad1 mutants are phytochelatin deficient and cadmium hypersensitive. the arabidopsis genome contains a highly homologous gene, atpcs2, of which expression and function were studied in order to understand the apparent non-redundancy of the two genes. low constitutive atpcs2 expression is detected in all plant or ... | 2001 | 11684101 |
| rnai-mediated oncogene silencing confers resistance to crown gall tumorigenesis. | crown gall disease, caused by the soil bacterium agrobacterium tumefaciens, results in significant economic losses in perennial crops worldwide. a. tumefaciens is one of the few organisms with a well characterized horizontal gene transfer system, possessing a suite of oncogenes that, when integrated into the plant genome, orchestrate de novo auxin and cytokinin biosynthesis to generate tumors. specifically, the iaam and ipt oncogenes, which show approximately 90% dna sequence identity across stu ... | 2001 | 11687652 |
| floral transcription factor agamous interacts in vitro with a leucine-rich repeat and an acid phosphatase protein complex. | we are interested in identifying potential protein interactors of mads domain transcription factors during arabidopsis thaliana flower development. we based our biochemical search on a conserved motif in the mads domain that includes putative phosphatase and phosphorylation sites that may mediate protein interactions. an affinity column with this motif and a few surrounding hypervariable amino acids derived from the agamous sequence was prepared and used to isolate potential interactors from flo ... | 2001 | 11689012 |
| the arabidopsis thaliana genome contains at least 29 active genes encoding set domain proteins that can be assigned to four evolutionarily conserved classes. | set domains are conserved amino acid motifs present in chromosomal proteins that function in epigenetic control of gene expression. these proteins can be divided into four classes as typified by their drosophila members e(z), trx, ash1 and su(var)3-9. homologs of all four classes have been identified in yeast and mammals, but not in plants. a blastp screening of the arabidopsis genome identified 37 genes: three e(z) homologs, five trx homologs, four ash1 homologs and 15 genes similar to su(var)3 ... | 2001 | 11691919 |
| interaction of the response regulator arr4 with phytochrome b in modulating red light signaling. | the arabidopsis thaliana response regulator 4, expressed in response to phytochrome b action, specifically interacts with the extreme amino-terminus of the photoreceptor. the response regulator 4 stabilizes the active pfr form of phytochrome b in yeast and in planta, thus elevates the level of the active photoreceptor in vivo. accordingly, transgenic arabidopsis plants overexpressing the response regulator 4 display hypersensitivity to red light but not to light of other wavelengths. we propose ... | 2001 | 11691995 |
| impaired expression of the plastidic ferrochelatase by antisense rna synthesis leads to a necrotic phenotype of transformed tobacco plants. | protoporphyrin ix is the last common intermediate of tetrapyrrole biosynthesis. the chelation of a mg2+ ion by magnesium chelatase and of a ferrous ion by ferrochelatase directs protoporphyrin ix towards the formation of chlorophyll and heme, respectively. a full length cdna clone encoding a ferrochelatase was identified from a nicotiana tabacum cdna library. the encoded protein consists of 497 amino acid residues with a molecular weight of 55.4 kda. in vitro import of the protein into chloropla ... | 2001 | 11696185 |
| differential subcellular localization of hzip1 in adherent and non-adherent cells. | two human divalent cation transporters of the zip family, hzip1 and hzip2, homologous to irt1 (arabidopsis thaliana), the first identified member, have been described. they were shown by transfection into k562 cells to be localized at the plasma membrane and to mediate zinc uptake. here we report a differential subcellular localization of hzip1 according to cell type. by transient expressions of egfp-hzip1, flag-tagged or native hzip1, we observed that hzip1 has a vesicular localization in cos-7 ... | 2001 | 11696349 |
| evolution of the rab family of small gtp-binding proteins. | rab proteins are small gtp-binding proteins that form the largest family within the ras superfamily. rab proteins regulate vesicular trafficking pathways, behaving as membrane-associated molecular switches. here, we have identified the complete rab families in the caenorhabditis elegans (29 members), drosophila melanogaster (29), homo sapiens (60) and arabidopsis thaliana (57), and we defined criteria for annotation of this protein family in each organism. we studied sequence conservation patter ... | 2001 | 11697911 |
| an unexpected plethora of trehalose biosynthesis genes in arabidopsis thaliana. | trehalose accumulation has been documented in many organisms, such as bacteria and fungi, where it serves a storage and stress-protection role. although conspicuously absent in most plants, trehalose biosynthesis genes were discovered recently in higher plants. we have uncovered a family of 11 tps genes in arabidopsis thaliana, one of which encodes a trehalose-6-phosphate (tre6p) synthase, and a subfamily of which might encode the still elusive tre6p phosphatases. a regulatory role in carbon met ... | 2001 | 11701378 |
| a novel plant kinesin-related protein specifically associates with the phragmoplast organelles. | in higher plants, the formation of the cell plate during cytokinesis requires coordinated microtubule (mt) reorganization and vesicle transport in the phragmoplast. mt-based kinesin motors are important players in both processes. to understand the mechanisms underlying plant cytokinesis, we have identified atpakrp2 (for arabidopsis thaliana phragmoplast-associated kinesin-related protein 2). atpakrp2 is an ungrouped n-terminal motor kinesin. it first appeared in a punctate pattern among interzon ... | 2001 | 11701879 |
| role of sh3 domain-containing proteins in clathrin-mediated vesicle trafficking in arabidopsis. | a group of plant atsh3ps (arabidopsis thaliana sh3-containing proteins) involved in trafficking of clathrin-coated vesicles was identified from the genbank database. these proteins contained predicted coiled-coil and src homology 3 (sh3) domains that are similar to animal and yeast proteins involved in the formation, fission, and uncoating of clathrin-coated vesicles. subcellular fractionation and immunolocalization studies confirmed the presence of atsh3p1 in the endomembrane system. in particu ... | 2001 | 11701884 |
| cas1p is a membrane protein necessary for the o-acetylation of the cryptococcus neoformans capsular polysaccharide. | the capsule is certainly the most obvious virulence factor for cryptococcus neoformans. the main capsule constituents are glucuronoxylomannans (gxm). several studies have focused on the structure and chemistry of the gxm component of the capsule, yet little is known about the genetic basis of the capsule construction. using a monoclonal antibody specific to a sugar epitope, we isolated a capsule-structure mutant strain and cloned by complementation a gene named cas1 that codes for a putative mem ... | 2001 | 11703667 |
| molecular characterization of the homo-phytochelatin synthase of soybean glycine max: relation to phytochelatin synthase. | the phytochelatin homologs homo-phytochelatins are heavy metal-binding peptides present in many legumes. to study the biosynthesis of these compounds, we have isolated and functionally expressed a cdna gmhpcs1 encoding homo-phytochelatin synthase from glycine max, a plant known to accumulate homo-phytochelatins rather than phytochelatins upon the exposure to heavy metals. the catalytic properties of gmhpcs1 were compared with the phytochelatin synthase atpcs1 from arabidopsis thaliana. when assa ... | 2002 | 11706029 |
| expression of ph-sensitive green fluorescent protein in arabidopsis thaliana. | this is the first report on using green fluorescent protein (gfp) as a ph reporter in plants. proton fluxes and ph regulation play important roles in plant cellular activity and therefore, it would be extremely helpful to have a plant gene reporter system for rapid, non-invasive visualization of intracellular ph changes. in order to develop such a system, we constructed three vectors for transient and stable transformation of plant cells with a ph-sensitive derivative of green fluorescent protei ... | 2001 | 11706851 |
| functional identification of sterol-4alpha-methyl oxidase cdnas from arabidopsis thaliana by complementation of a yeast erg25 mutant lacking sterol-4alpha-methyl oxidation. | specific primers derived from both genomic sequence data and est cdna sequences were used to polymerase chain reaction amplify two full-length cdna sequences (atsmo1 and atsmo2), 801 and 783 bp, respectively, from an arabidopsis thaliana cdna library. the predicted proteins show 32 and 29% identity to the erg25 gene from saccharomyces cerevisiae which encodes the sterol-4alpha-methyl oxidase (smo), a membrane-bound non-heme di-iron oxygenase involved in lipid metabolism. heterologous expression ... | 2001 | 11707264 |
| purification of plant protein phosphatase pp7 and evidence for its redox regulation. | pp7, a recently identified protein ser/thr phosphatase of the ppp family distantly related to phosphatases pp5/ppt and ppef/rdgc, was purified from cauliflower extracts to apparent homogeneity. purified cauliflower pp7 and recombinant pp7 expressed in escherichia coli exhibit light absorption in the visible range with a maximum at approximately 430 nm. under nonreducing conditions, native pp7 exists as a mixture of monomer with an intramolecular disulfide bridge, disulfide-linked homodimer, and ... | 2001 | 11716463 |
| differential roles of the pseudomonas aeruginosa pa14 rpon gene in pathogenicity in plants, nematodes, insects, and mice. | we cloned the rpon (ntra, glnf) gene encoding the alternate sigma factor sigma(54) from the opportunistic multihost pathogen pseudomonas aeruginosa strain pa14. a marker exchange protocol was used to construct the pa14 rpon insertional mutation rpon::gen(r). pa14 rpon::gen(r) synthesized reduced levels of pyocyanin and displayed a variety of phenotypes typical of rpon mutants, including a lack of motility and the failure to grow on nitrate, glutamate, or histidine as the sole nitrogen source. co ... | 2001 | 11717271 |
| identification and characterization of a mitochondrial thioredoxin system in plants. | plants possess two well described thioredoxin systems: a cytoplasmic system including several thioredoxins and an nadph-dependent thioredoxin reductase and a specific chloroplastic system characterized by a ferredoxin-dependent thioredoxin reductase. on the basis of biochemical activities, plants also are supposed to have a mitochondrial thioredoxin system as described in yeast and mammals, but no gene encoding plant mitochondrial thioredoxin or thioredoxin reductase has been identified yet. we ... | 2001 | 11717467 |
| chlorophyll b can serve as the major pigment in functional photosystem ii complexes of cyanobacteria. | an arabidopsis thaliana chlorophyll(ide) a oxygenase gene (cao), which is responsible for chlorophyll b synthesis from chlorophyll a, was introduced and expressed in a photosystem i-less strain of the cyanobacterium synechocystis sp. pcc 6803. in this strain, most chlorophyll is associated with the photosystem ii complex. in line with observations by satoh et al. [satoh, s., ikeuchi, m., mimuro, m. & tanaka, a. (2001) j. biol. chem. 276, 4293-4297], chlorophyll b was made but accounted for less ... | 2001 | 11717469 |
| study of intrachromosomal duplications among the eukaryote genomes. | complete eukaryote chromosomes were investigated for intrachromosomal duplications of nucleotide sequences. the analysis was performed by looking for nonexact repeats on two complete genomes, saccharomyces cerevisiae and caenorhabditis elegans, and four partial ones, drosophila melanogaster, plasmodium falciparum, arabidopsis thaliana, and homo sapiens. through this analysis, we show that all eukaryote chromosomes exhibit similar characteristics for their intrachromosomal repeats, suggesting sim ... | 2001 | 11719577 |
| the mads-box gene defh28 from antirrhinum is involved in the regulation of floral meristem identity and fruit development. | defh28 is a novel mads-box gene from antirrhinum majus. phylogenetic reconstruction indicates that it belongs to the squa-subfamily of mads-box genes. based on its expression pattern and the phenotype of transgenic plants it is predicted that defh28 exerts a dual function during flower development, namely control of meristem identity and fruit development. firstly, defh28 is expressed in the inflorescence apical meristem and might control, together with squamosa (squa), floral meristem identity ... | 2001 | 11722760 |
| a plastid envelope location of arabidopsis ent-kaurene oxidase links the plastid and endoplasmic reticulum steps of the gibberellin biosynthesis pathway. | we have used fusions of gibberellin biosynthesis enzymes to green fluorescent protein (gfp) to determine the subcellular localization of the early steps of the pathway. gibberellin biosynthesis from geranylgeranyl diphosphate is catalysed by enzymes of the terpene cyclase, cytochrome p450 mono-oxygenase and 2-oxoglutarate-dependent dioxygenase classes. we show that the n-terminal pre-sequences of the arabidopsis thaliana terpene cyclases copalyl diphosphate synthase (atcps1) and ent-kaurene synt ... | 2001 | 11722763 |
| characterization of the ethanol-inducible alc gene-expression system in arabidopsis thaliana. | controlled expression of transgenes in plants is key to the characterization of gene function and the regulated manipulation of growth and development. the alc gene-expression system, derived from the filamentous fungus aspergillus nidulans, has previously been used successfully in both tobacco and potato, and has potential for use in agriculture. its value to fundamental research is largely dependent on its utility in arabidopsis thaliana. we have undertaken a detailed function analysis of the ... | 2001 | 11722766 |
| linear dna intermediates of the tto1 retrotransposon in gag particles accumulated in stressed tobacco and arabidopsis thaliana. | the active transcription of some plant retrotransposons under diverse stress conditions suggests active transposition. however, transposition has been demonstrated only during tissue/cell culture. to examine whether transposition is activated under conditions other than tissue/cell culture, dna intermediates for retrotransposition of the tobacco retrotransposon tto1 were analysed. using transgenic arabidopsis callus expressing high levels of tto1 rna in a ddm1 hypomethylation mutant background, ... | 2001 | 11722773 |
| a cell-cycle-regulated kinase activity phosphorylates plant retinoblastoma protein and contains, in arabidopsis, a cdka/cyclin d complex. | the activity of cyclin-dependent kinases (cdk) is crucial for cell-cycle transitions. here, we report the identification of a cdk activity that phosphorylates the retinoblastoma-related (rbr) protein. a cdk/cyclin complex that binds to and phosphorylates rbr may be isolated from various plant sources, e.g. wheat, maize, arabidopsis thaliana and tobacco, and from cells growing under various conditions. the presence of an rbr-associated cdk activity correlates with the proliferative activity, sugg ... | 2001 | 11722776 |
| characterization of an arabidopsis cdna encoding a subunit of serine palmitoyltransferase, the initial enzyme in sphingolipid biosynthesis. | serine palmitoyltransferase (spt; ec 2.3.1.50) catalyzes the condensation of serine with palmitoyl-coa to form 3-ketosphinganine in the first step of de novo sphingolipid biosynthesis. in this study, we describe the cloning and functional characterization of a cdna from arabidopsis thaliana encoding the lcb2 subunit of spt. the arabidopsis lcb2 (atlcb2) cdna contains an open reading frame of 1,467 nucleotides, encoding 489 amino acids. the predicted polypeptide contains three transmembrane helic ... | 2001 | 11726713 |
| the arabidopsis thaliana ethylene-responsive element binding protein (atebp) can function as a dominant suppressor of bax-induced cell death of yeast. | we identified genes based on screening of an arabidopsis cdna library for functional suppressors of mouse bax-induced cell death of yeast cells. interestingly, the cdna encoding atebp, known as arabidopsis thaliana ethylene-responsive element binding protein, was isolated numerous times in the functional screen (82% of all suppressors). full-length atebp and its localization to the nucleus were essential for the suppression of bax-induced cell death. morphological abnormality of intracellular ne ... | 2001 | 11728455 |
| purification and characterization of a galactose-specific lectin from corn (zea mays) coleoptile. | we purified and characterized a lectin from the corn coleoptyle (zea mays). the lectin (ccl) was purified by affinity chromatography on a lactosyl-sepharose 4b column. it is a glycoprotein of 88.7 kda, composed mainly by glutamic, aspartic, glycine, and ser residues; in a minor proportion, it contained methionine and cysteine residues. carbohydrates that constituted 12% of the total weight comprised galactose, mannose, and n-acetyl-d-glucosamine. the lectin contained the blocked amino-terminus. ... | 2001 | 11731083 |
| evolution of intron/exon structure of dead helicase family genes in arabidopsis, caenorhabditis, and drosophila. | the dead box rna helicase (rh) proteins are homologs involved in diverse cellular functions in all of the organisms from prokaryotes to eukaryotes. nevertheless, there is a lack of conservation in the splicing pattern in the 53 arabidopsis thaliana (atrhs), the 32 caenorhabditis elegans (cerhs) and the 29 drosophila melanogaster (dmrhs) genes. of the 153 different observed intron positions, 4 are conserved between atrhs, cerhs, and dmrhs, and one position is also found in rhs from yeast and huma ... | 2001 | 11731501 |
| dynamic changes in the frequency and architecture of plasmodesmata during the sink-source transition in tobacco leaves. | the sink-source transition in tobacco leaves was studied noninvasively using transgenic plants expressing the green-fluorescent protein (gfp) under control of the arabidopsis thaliana suc2 promoter, and also by imaging transgenic plants that constitutively expressed a tobacco mosaic virus movement protein (mp) fused to gfp (mp-gfp). the sink-source transition was measured on intact leaves and progressed basipetally at rates of up to 600 microns/h. the transition was most rapid on the largest sin ... | 2001 | 11732318 |
| maximum likelihood methods reveal conservation of function among closely related kinesin families. | we have reconstructed the evolution of the anciently derived kinesin superfamily using various alignment and tree-building methods. in addition to classifying previously described kinesins from protists, fungi, and animals, we analyzed a variety of kinesin sequences from the plant kingdom including 12 from zea mays and 29 from arabidopsis thaliana. also included in our data set were four sequences from the anciently diverged amitochondriate protist giardia lamblia. the overall topology of the be ... | 2002 | 11734897 |
| the stat3/5 locus encodes novel endoplasmic reticulum and helicase-like proteins that are preferentially expressed in normal and neoplastic mammary tissue. | the signal transducers and activators of transcription (stat) 5 and 3 are critical for mammary alveolar development during pregnancy and remodeling during involution. in the mouse, stat3, stat5a, and stat5b are encoded by adjacent genes on chromosome 11 (60.5 cm). to identify additional genes in the stat3/5 locus that may participate in normal and neoplastic development of the mammary gland, we have cloned and sequenced 500 kb and searched for genes preferentially expressed in mammary tissue. we ... | 2001 | 11735219 |
| the participation of atxpb1, the xpb/rad25 homologue gene from arabidopsis thaliana, in dna repair and plant development. | nucleotide excision repair in arabidopsis thaliana differs from other eukaryotes as it contains two paralogous copies of the corresponding xpb/rad25 gene. in this work, the functional characterization of one copy, atxpb1, is presented. the plant gene was able to partially complement the uv sensitivity of a yeast rad25 mutant strain, thus confirming its involvement in nucleotide excision repair. the biological role of atxpb1 protein in a. thaliana was further ascertained by obtaining a homozygous ... | 2001 | 11737776 |
| a high-throughput method for quantifying growth of phytopathogenic bacteria in arabidopsis thaliana. | measuring the growth of pathogenic bacteria in leaves is a mainstay of plant pathology studies. we have made significant improvements to standard methods that will not only increase the throughput but also reduce the space limitations. additionally, the method described here is as accurate as the standard method. briefly, we infected leaves by dipping whole seedlings of arabidopsis into a bacterial solution containing a surfactant. after harvest, the seedlings were then simply shaken in buffer. ... | 2001 | 11737784 |
| detection of chromosomes tagged with green fluorescent protein in live arabidopsis thaliana plants. | structural and dynamic studies of chromosomes tagged with green fluorescent protein (gfp) in yeast and cultured animal cells have revealed some surprises. although this technology can be very powerful, only a few studies using this approach with developed multicellular systems have been reported for the study of chromatin behavior in situ. | 2001 | 11737944 |
| functional cloning and characterization of a plant efflux carrier for multidrug and heavy metal detoxification. | we have identified a detoxifying efflux carrier from arabidopsis using a functional cloning strategy. a bacterial mutant, kam3, is deficient in multidrug resistance and does not survive on medium containing norfloxacin. after transformation of kam3 cells with an arabidopsis cdna library, transformants were selected for restored growth on the toxic medium. one cdna clone that complemented kam3 encodes a novel protein with twelve putative transmembrane domains and contains limited sequence homolog ... | 2002 | 11739388 |
| phosphatidylglycerophosphate synthases from arabidopsis thaliana. | two arabidopsis thaliana genes were shown to encode phosphatidylglycerophosphate synthases (pgps) of 25.4 and 32.2 kda, respectively. apart from their n-terminal regions, the two proteins exhibit high sequence similarity. functional expression studies in yeast provided evidence that the 25.4 kda protein is a microsomal pgps while the 32.2 kda protein represents a preprotein which can be imported into yeast mitochondria and processed to a mature pgps. the two isozymes were solubilized and purifie ... | 2001 | 11741606 |
| post-translational modification of plant plasma membrane h(+)-atpase as a requirement for functional complementation of a yeast transport mutant. | many heterologous membrane proteins expressed in the yeast saccharomyces cerevisiae fail to reach their normal cellular location and instead accumulate in stacked internal membranes. arabidopsis thaliana plasma membrane h(+)-atpase isoform 2 (aha2) is expressed predominantly in yeast internal membranes and fails to complement a yeast strain devoid of its endogenous h(+)-atpase pma1. we observed that phosphorylation of aha2 in the heterologous host and subsequent binding of 14-3-3 protein is cruc ... | 2002 | 11744700 |
| steroid signaling in plants: from the cell surface to the nucleus. | steroid hormones are signaling molecules important for normal growth, development and differentiation of multicellular organisms. brassinosteroids (brs) are a class of polyhydroxylated steroids that are necessary for plant development. molecular genetic studies in arabidopsis thaliana have led to the cloning and characterization of the br receptor, bri1, which is a transmembrane receptor serine/threonine kinase. the extracellular domain of bri1, which is composed mainly of leucine-rich repeats, ... | 2001 | 11746219 |
| monitoring the switch from housekeeping to pathogen defense metabolism in arabidopsis thaliana using cdna arrays. | plants respond to pathogen attack by deploying several defense reactions. some rely on the activation of preformed components, whereas others depend on changes in transcriptional activity. using cdna arrays comprising 13,000 unique expressed sequence tags, changes in the transcriptome of arabidopsis thaliana were monitored after attempted infection with the bacterial plant pathogen pseudomonas syringae pv. tomato carrying the avirulence gene avrrpt2. sampling at four time points during the first ... | 2002 | 11748215 |
| characterisation of a concentrative type of adenosine transporter from arabidopsis thaliana (ent1,at). | here we report on the isolation of an arabidopsis thaliana cdna that is able to complement a saccharomyces cerevisiae mutant unable to synthesise adenine. this cdna encodes a highly hydrophobic protein (ent1,at) of 428 amino acids, showing high similarity to the human nucleoside transporter hent1. yeast cells expressing ent1,at are able to grow on adenosine-containing media, adenosine import exhibited an apparent affinity (k(m)) of 3.6 microm, and led to accumulation of this nucleoside within th ... | 2001 | 11749958 |
| the fission yeast es2 homologue, bis1, interacts with the ish1 stress-responsive nuclear envelope protein. | in fission yeast, nutrient starvation induces physiological, biochemical, and morphological changes that enable survival. collectively these changes are referred to as stationary phase. we have used a green fluorescent protein random insertional mutagenesis system to isolate two novel stress-response proteins required in stationary phase. ish1 is a nuclear envelope protein that is present throughout the cell cycle and whose expression is increased in response to stresses such as glucose and nitr ... | 2002 | 11751918 |
| systers, genenest, splicenest: exploring sequence space from genome to protein. | we have integrated the protein families from systers and the expressed sequence tag (est) clusters from our database genenest with splicenest, a new database mapping est contigs into genomic dna. the systers protein sequence cluster set provides an automatically generated classification of all sequences of the swiss-prot, trembl and pir databases into disjoint protein family and superfamily clusters. genenest is a database and software package for producing and visualizing gene indices from ests ... | 2002 | 11752319 |
| partial purification and identification of gdp-mannose 3",5"-epimerase of arabidopsis thaliana, a key enzyme of the plant vitamin c pathway. | the first step in the biosynthetic pathway of vitamin c in plants is the formation, at the level of sugar nucleotide, of l-galactosyl residues, catalyzed by a largely unknown gdp-d-mannose 3",5"-epimerase. by using combined conventional biochemical and mass spectrometry methods, we obtained a highly purified preparation of gdp-d-mannose 3",5"-epimerase from an arabidopsis thaliana cell suspension. the native enzyme is an 84-kda dimer, composed of two apparently identical subunits. in-gel tryptic ... | 2001 | 11752432 |
| tetrahydrofolate biosynthesis in plants: molecular and functional characterization of dihydrofolate synthetase and three isoforms of folylpolyglutamate synthetase in arabidopsis thaliana. | tetrahydrofolate coenzymes involved in one-carbon (c1) metabolism are polyglutamylated. in organisms that synthesize tetrahydrofolate de novo, dihydrofolate synthetase (dhfs) and folylpolyglutamate synthetase (fpgs) catalyze the attachment of glutamate residues to the folate molecule. in this study we isolated cdnas coding a dhfs and three isoforms of fpgs from arabidopsis thaliana. the function of each enzyme was demonstrated by complementation of yeast mutants deficient in dhfs or fpgs activit ... | 2001 | 11752472 |
| [establishment of trans-inactivation system for haloalkane dehalogenase gene in arabidopsis thaliana]. | with haloalkane dehalogenase gene (dhla) of xanthobacter autothophicus as a negative selection marker, a novel trans-inactivation system for transgenes in plants was developed. after the arabidopsis plants were transformed with dhla, one plant was shown dhla post-transcriptional silencing by nuclear run-off transcriptional analysis. the arabidopsis plants containing silencing locus were crossed to those efficiently expressed dhla, referred as a homologous transgenic locus, and 96% of f1 plants b ... | 2001 | 11757378 |
| inhibition of cell proliferation, cell expansion and differentiation by the arabidopsis superman gene in transgenic tobacco plants. | plant development depends upon the control of growth, organization and differentiation of cells derived from shoot and root meristems. among the genes involved in flower organ determination, the cadastral gene superman controls the boundary between whorls 3 and 4 and the growth of the adaxial outer ovule integument by down-regulating cell divisions. to determine the precise function of this gene we overexpressed ectopically the arabidopsis thaliana (l.) heynh. superman gene in tobacco (nicotiana ... | 2001 | 11762167 |
| effects of the mur1 mutation on xyloglucans produced by suspension-cultured arabidopsis thaliana cells. | mutation of the arabidopsis thaliana (l.) heynh. gene mur1, which encodes an isoform of gdp-d-mannose-4,6-dehydratase, affects the biosynthetic conversion of gdp-mannose to gdp-fucose. cell walls in the aerial tissues of mur1 plants are almost devoid of alpha-l-fucosyl residues, which are partially replaced by closely related alpha-l-galactosyl residues. a line of suspension-cultured a. thaliana cells was generated from leaves of mur1 plants and the structure of the xyloglucan in the walls of th ... | 2001 | 11762172 |
| insertional mutagenesis of genes required for seed development in arabidopsis thaliana. | the purpose of this project was to identify large numbers of arabidopsis genes with essential functions during seed development. more than 120,000 t-dna insertion lines were generated following agrobacterium-mediated transformation. transgenic plants were screened for defective seeds and putative mutants were subjected to detailed analysis in subsequent generations. plasmid rescue and tail-pcr were used to recover plant sequences flanking insertion sites in tagged mutants. more than 4200 mutants ... | 2001 | 11779812 |
| analysis of the 5s rna pool in arabidopsis thaliana: rnas are heterogeneous and only two of the genomic 5s loci produce mature 5s rna. | one major 5s rna, 120 bases long, was revealed by an analysis of mature 5s rna from tissues, developmental stages, and polysomes in arabidopsis thaliana. minor 5s rna were also found, varying from the major one by one or two base substitutions; 5s rdna units from each 5s array of the arabidopsis genome were isolated by pcr using cic yeast artificial chromosomes (yacs) mapped on the different loci. by using a comparison of the 5s dna and rna sequences, we could show that both major and minor 5s t ... | 2002 | 11779838 |