| the plant pathogen rhodococcus fascians colonizes the exterior and interior of the aerial parts of plants. | rhodococcus fascians is a plant-pathogenic bacterium that causes malformations on aerial plant parts, whereby leafy galls occur at axillary meristems. the colonization behavior on nicotiana tabacum and arabidopsis thaliana plants was examined. independent of the infection methods, r. fascians extensively colonized the plant surface where the bacteria were surrounded by a slime layer. r. fascians caused the collapse of epidermal cells and penetrated intercellularly into the plant tissues. the ons ... | 2001 | 11332724 |
| the leucine-rich repeat domain can determine effective interaction between rps2 and other host factors in arabidopsis rps2-mediated disease resistance. | like many other plant disease resistance genes, arabidopsis thaliana rps2 encodes a product with nucleotide-binding site (nbs) and leucine-rich repeat (lrr) domains. this study explored the hypothesized interaction of rps2 with other host factors that may be required for perception of pseudomonas syringae pathogens that express avrrpt2 and/or for the subsequent induction of plant defense responses. crosses between arabidopsis ecotypes col-0 (resistant) and po-1 (susceptible) revealed segregation ... | 2001 | 11333251 |
| cyp83b1 is the oxime-metabolizing enzyme in the glucosinolate pathway in arabidopsis. | cyp83b1 from arabidopsis thaliana has been identified as the oxime-metabolizing enzyme in the biosynthetic pathway of glucosinolates. biosynthetically active microsomes isolated from sinapis alba converted p-hydroxyphenylacetaldoxime and cysteine into s-alkylated p-hydroxyphenylacetothiohydroximate, s-(p-hydroxyphenylacetohydroximoyl)-l-cysteine, the next proposed intermediate in the glucosinolate pathway. the production was shown to be dependent on a cytochrome p450 monooxygenase. we searched t ... | 2001 | 11333274 |
| mitochondrial uncoupling proteins and phylogenesis--ucp4 as the ancestral uncoupling protein. | we searched for the previously defined uncoupling protein (ucp) signatures [jezek, p. and urbánková, e. (2000) iubmb life 49, 63-70] in genomes of drosophila melanogaster, caenorhabditis elegans, dictyostelium discoideum, and arabidopsis thaliana. we identified four ucps in drosophila and one in caenorhabditis or dictyostelium as close relatives of human ucp4 (bmcp), but distant from ucp1, ucp2, ucp3, and two plant ucps of arabidopsis. but the third arabidopsis ucp is the closest ucp4 relative. ... | 2001 | 11334880 |
| elevated sensitivity to gibberellin by vernalization in the vegetative rosette plants of eustoma grandiflorum and arabidopsis thaliana. | changes in the sensitivity to gibberellin (ga) after vernalization were studied in the vegetative rosette of eustoma grandiflorum and late flowering arabidopsis thaliana mutant, fca-1. the sensitivity to ga after vernalization was monitored using the bolting rate of plants that were grown on a medium containing ga(3) or ancymidol. the bolting rates were higher in vernalized plants than non-vernalized plants when the same ga(3) concentration was used. there was a positive relationship between the ... | 2001 | 11337081 |
| evidence in support of a four transmembrane-pore-transmembrane topology model for the arabidopsis thaliana na+/k+ translocating athkt1 protein, a member of the superfamily of k+ transporters. | the arabidopsis thaliana athkt1 protein, a na(+)/k(+) transporter, is capable of mediating inward na(+) currents in xenopus laevis oocytes and k(+) uptake in escherichia coli. hkt1 proteins are members of a superfamily of k(+) transporters. these proteins have been proposed to contain eight transmembrane segments and four pore-forming regions arranged in a mode similar to that of a k(+) channel tetramer. however, computer analysis of the athkt1 sequence identified eleven potential transmembrane ... | 2001 | 11344270 |
| the arabidopsis thaliana abc protein superfamily, a complete inventory. | we describe the first complete inventory of atp-binding cassette (abc) proteins from a multicellular organism, the model plant arabidopsis thaliana. by the application of several search criteria, arabidopsis was found to contain a total of 129 open reading frames (orfs) capable of encoding abc proteins, of which 103 possessed contiguous transmembrane spans and were identified as putative intrinsic membrane proteins. fifty-two of the putative intrinsic membrane proteins contained at least two tra ... | 2001 | 11346655 |
| isolation of cdna and genomic dna clones encoding a calmodulin-binding protein related to a family of atpases involved in cell division and vesicle fusion. | calmodulin (cam), a primary ca2+ receptor in all eukaryotic cells, is a multifunctional protein that functions by interacting with and modulating the activities of a wide variety of target proteins. identifying and characterizing these cam-binding target proteins is essential to define the pathways by which ca(2+)-regulated signals are transduced. an arabidopsis thaliana l. flower cdna expression library constructed in lambda zapii was screened for cam-binding proteins with 35s-labeled cam. a pa ... | 2001 | 11346951 |
| two iron-regulated cation transporters from tomato complement metal uptake-deficient yeast mutants. | although iron deficiency poses severe nutritional problems to crop plants, to date iron transporters have only been characterized from the model plant arabidopsis thaliana. to extend our molecular knowledge of fe transport in crop plants, we have isolated two cdnas (leirt1 and leirt2) from a library constructed from roots of iron-deficient tomato (lycopersicon esculentum) plants, using the arabidopsis iron transporter cdna, irti, as a probe. their deduced polypeptides display 64% and 62% identic ... | 2001 | 11352462 |
| plant mitochondria contain proteolytic and regulatory subunits of the atp-dependent clp protease. | the proteolytic machinery of plant organelles is largely unknown, although indications so far point to several proteases of bacterial origin. in this study an arabidopsis thaliana cdna was isolated that encodes a homologue of bacterial clpx, a molecular chaperone and regulatory subunit of the atp-dependent, serine-type clp protease. computer analysis of the predicted plant clpx revealed a putative mitochondrial transit peptide at the n-terminus, as well as overall sequence similarity to other eu ... | 2001 | 11352464 |
| identification and functional expression in yeast of a prenylcysteine alpha-carboxyl methyltransferase gene from arabidopsis thaliana. | most isoprenylated proteins are alpha-carboxyl-methylated. however, despite numerous studies linking protein isoprenylation in plants to cell cycle control, meristem development, and phytohormone signaling, alpha-carboxyl methylation of isoprenylated plant proteins has not been characterized in detail. here, we report the cloning of a prenylcysteine alpha-carboxyl methyltransferase gene (atste14) from arabidopsis thaliana. atste14 restores fertility and enzymatic activity to a ste14 mutant of sa ... | 2001 | 11352465 |
| tobacco and arabidiopsis slt1 mediate salt tolerance of yeast. | a tobacco cdna (ntslt1, for nicotiana tabacum sodium- and lithium-tolerant) was isolated by functional complementation of the salt-sensitive phenotype of a calcineurin (can)-deficient yeast mutant (cnb delta, regulatory subunit null). can is a ca2+/calmodulin-dependent type 2b protein phosphatase that regulates na+ homeostasis in yeast. this phosphatase modulates plasma membrane k+/na+ selectivity through the activation of high-affinity k+ transport, and increaseses extracellular na+ efflux by a ... | 2001 | 11352467 |
| molecular biology of the plastidic phosphorylated serine biosynthetic pathway in arabidopsis thaliana. | serine biosynthesis in plants proceeds by two pathways; the glycolate pathway which is associated with photorespiration and the pathway from 3-phosphoglycerate which is presumed to take place in the plastids. the 3-phosphoglycerate pathway (phosphorylated pathway) involves three enzymes catalyzing three sequential reactions: 3-phosphoglycerate dehydrogenase (pgdh), 3-phosphoserine aminotransferase (psat) and 3-phosphoserine phosphatase (psp). cdna and genomic clones encoding these three enzymes ... | 2001 | 11354602 |
| functional characterization of recombinant chloroplast signal recognition particle. | the signal recognition particle (srp) is a ubiquitous system for the targeting of membrane and secreted proteins. the chloroplast srp (cpsrp) is unique among srps in that it possesses no rna and is functional in post-translational as well as co-translational targeting. we have expressed and purified the two components of the arabidopsis thaliana chloroplast signal recognition particle (cpsrp) involved in post-translational transport: cpsrp54 and the chloroplast-specific protein, cpsrp43. recombi ... | 2001 | 11356852 |
| cyp94a5, a new cytochrome p450 from nicotiana tabacum is able to catalyze the oxidation of fatty acids to the omega-alcohol and to the corresponding diacid. | a full length cdna encoding a new cytochrome p450-dependent fatty acid hydroxylase (cyp94a5) was isolated from a tobacco cdna library. cyp94a5 was expressed in s. cerevisiae strain wat11 containing a p450 reductase from arabidopsis thaliana necessary for catalytic activity of cytochrome p450 enzymes. when incubated for 10 min in presence of nadph with microsomes of recombinant yeast, 9,10-epoxystearic acid was converted into one major metabolite identified by gc/ms as 18-hydroxy-9,10-epoxysteari ... | 2001 | 11358528 |
| molecular characterization of the 4'-phosphopantothenoylcysteine decarboxylase domain of bacterial dfp flavoproteins. | the nh(2)-terminal domain of the bacterial flavoprotein dfp catalyzes the decarboxylation of (r)-4'-phospho-n-pantothenoylcysteine to 4'-phosphopantetheine, a key step in coenzyme a biosynthesis. dfp proteins, land proteins (for example epid, which is involved in epidermin biosynthesis), and the salt tolerance protein athal3a from arabidopsis thaliana are homooligomeric flavin-containing cys decarboxylases (hfcd protein family). the crystal structure of the peptidyl-cysteine decarboxylase epid c ... | 2001 | 11358972 |
| a functional ogg1 homologue from arabidopsis thaliana. | one of the major mutagenic base lesions in dna caused by exposure to reactive oxygen species is 7,8-dihydro-8-oxoguanine (8-oxog). genes coding for dna repair enzymes that recognise 8-oxog have been reported in bacteria, yeast, mammals and plants. the prokaryotic and eukaryotic genes are functional homologues but differ in their primary sequence. we have cloned, sequenced, and expressed a new arabidopsis thaliana cdna that shows sequence homology to the eukaryotic genes coding for 8-oxog dna n-g ... | 2001 | 11361340 |
| characterisation of a zeta class glutathione transferase from arabidopsis thaliana with a putative role in tyrosine catabolism. | a glutathione transferase (gst) similar to zeta gsts in animals and fungi has been cloned from arabidopsis thaliana using rt-pcr. the arabidopsis zeta gst (atgstz1) was expressed in escherichia coli as his-tagged polypeptides, which associated together to form the 50-kda atgstz1-1 homodimer. following purification, atgstz1-1 was assayed for a range of activities and compared with other purified recombinant plant gsts from the phi, tau, and theta classes. atgstz1-1 differed from the other gsts in ... | 2000 | 11368331 |
| cloning and characterization of the gene encoding 3-hydroxy-3-methylglutaryl coenzyme a reductase in melon (cucumis melo l. reticulatus). | we have isolated a cdna for cm-hmgr, encoding 3-hydroxy-3-methylglutaryl coenzyme a (hmg-coa) reductase in melon (cucumis melo l. reticulatus; genbank accession no. ab021862). cm-hmgr encodes a polypeptide of 588 amino acids that contains two transmembrane domains and a catalytic domain. database searches revealed that cm-hmgr shows homology to hmg1 (63.7%) and hmg2 (70.3%) of tomato, to hmg1 (77.2%) and hmg2 (69.4%) of arabidopsis thaliana, and to hmgr of tobacco (72.6%). functional expression ... | 2001 | 11370859 |
| tnt1 transposition events are induced by in vitro transformation of arabidopsis thaliana, and transposed copies integrate into genes. | tissue culture has been shown to induce the transposition of plant transposable elements; their insertion at novel sites results in somaclonal variation. introduction of the tobacco retrotransposon tnt1 into arabidopsis thaliana by co-cultivation of root explants with agrobacterium tumefaciens induces its transposition at a high frequency, but no transposed copies are found in plants transformed by the in planta procedure. transposition occurs in the transformed root cells or in the calli derive ... | 2001 | 11370870 |
| large scale expression, purification and 2d crystallization of recombinant plant plasma membrane h+-atpase. | p-type atpases convert chemical energy into electrochemical gradients that are used to energize secondary active transport. analysis of the structure and function of p-type atpases has been limited by the lack of active recombinant atpases in quantities suitable for crystallographic studies aiming at solving their three-dimensional structure. we have expressed arabidopsis thaliana plasma membrane h+-atpase isoform aha2, equipped with a his(6)-tag, in the yeast saccharomyces cerevisiae. the h+-at ... | 2001 | 11371165 |
| ole e 9, a major olive pollen allergen is a 1,3-beta-glucanase. isolation, characterization, amino acid sequence, and tissue specificity. | olive pollen allergy is a clinical disorder affecting the human population of mediterranean areas. a novel major allergen, ole e 9, has been isolated from olive pollen by gel permeation, hydrophobic affinity, and reverse-phase high performance liquid chromatographies. it is involved in the allergic responses of 65% of patients suffering olive pollinosis. ole e 9 (molecular mass of 46.4 kda) displays 1,3-beta-endoglucanase activity (38.9 +/- 5.6 mg of glucose released/min x micromol of protein at ... | 2001 | 11373288 |
| structure and expression of the arabidopsis thaliana homeobox gene athb-12. | we have isolated the arabidopsis thaliana homeobox gene athb-12, determined its structure and activation domain, demonstrated that its promoter is inducible in response to abscisic acid (aba) treatment, and characterized the cellular distribution of its transcripts. the single intron of the gene interrupted the leucine-zipper domain region. the 5' regulatory region of athb-12 can drive beta-glucuronidase (gus) expression in tobacco transgenic plants. athb-12 gene expression was further examined ... | 2001 | 11374882 |
| harpin, a hypersensitive response elicitor from erwinia amylovora, regulates ion channel activities in arabidopsis thaliana suspension cells. | hrpn, the hypersensitive response elicitor from erwinia amylovora, stimulated k(+) outward rectifying currents in arabidopsis thaliana suspension cells. it also decreased anion currents. these data demonstrate the ability of harpin to regulate different plasma membrane ion channels, putative components of signal transduction chains leading to defense responses and programmed cell death. | 2001 | 11377417 |
| n-terminal ef-hand-like domain is required for phosphoinositide-specific phospholipase c activity in arabidopsis thaliana. | phosphoinositide-specific phospholipase c's (pi-plcs) are ubiquitous in eukaryotes, from plants to animals, and catalyze the hydrolysis of phosphatidylinositol 4,5-bisphosphate into the two second messengers inositol 1,4,5-trisphosphate and diacylglycerol. in animals, four distinct subfamilies of pi-plcs have been identified, and the three-dimensional structure of one rat isozyme, plc-delta1, determined. plants appear to contain only one gene family encoding pi-plcs. the catalytic properties of ... | 2001 | 11377433 |
| computational analysis of human disease-associated genes and their protein products. | the complete genome sequences for human, drosophila melanogaster and arabidopsis thaliana have been reported recently. with the availability of complete sequences for many bacteria and archaea, and five eukaryotes, comparative genomics and sequence analysis are enabling us to identify counterparts of many human disease genes in model organisms, which in turn should accelerate the pace of research and drug development to combat human diseases. continuous improvement of specialized protein databas ... | 2001 | 11377959 |
| oxy5, a novel protein from arabidopsis thaliana, protects mammalian cells from oxidative stress. | the use of molecular oxygen in various cellular processes results in the generation of toxic intracellular by-products termed reactive oxygen species (ros). in escherichia coli the oxyr gene product is a transcriptional regulator of the oxyr regulon that is induced in response to hydrogen peroxide-induced oxidative stress (os). we have previously shown that an annexin-like protein from arabidopsis thaliana, termed oxy5, can replace the obligatory role of oxyr in e. coli. here, we have investigat ... | 2001 | 11378440 |
| regulation of systemic acquired resistance by npr1 and its partners. | the npr1 protein of arabidopsis thaliana has been shown to be an important regulatory component of systemic acquired resistance (sar). mutations in the npr1 gene block the induction of sar by the signal molecule salicylic acid (sa). npr1 contains an ankyrin repeats and a btb domain which are involved in interaction with other protein(s). to further study the function of npr1 and the regulatory mechanism of sar, we used both molecular and genetic approaches to identify additional sar regulatory c ... | 2001 | 11387978 |
| identification of the regulatory subunit of arabidopsis thaliana acetohydroxyacid synthase and reconstitution with its catalytic subunit. | acetohydroxyacid synthase (ec 4.1.3.18; ahas) catalyzes the initial step in the formation of the branched-chain amino acids. the enzyme from most bacteria is composed of a catalytic subunit, and a smaller regulatory subunit that is required for full activity and for sensitivity to feedback regulation by valine. a similar arrangement was demonstrated recently for yeast ahas, and a putative regulatory subunit of tobacco ahas has also been reported. in this latter case, the enzyme reconstituted fro ... | 2001 | 11389597 |
| arabidopsis irt2 gene encodes a root-periphery iron transporter. | iron uptake from the soil is a tightly controlled process in plant roots, involving specialized transporters. one such transporter, irt1, was identified in arabidopsis thaliana and shown to function as a broad-range metal ion transporter in yeast. here we report the cloning and characterization of the irt2 cdna, a member of the zip family of metal transporters, highly similar to irt1 at the amino-acid level. irt2 expression in yeast suppresses the growth defect of iron and zinc transport yeast m ... | 2001 | 11389759 |
| subcellular localization and oligomerization of the arabidopsis thaliana somatic embryogenesis receptor kinase 1 protein. | the arabidopsis thaliana somatic embryogenesis receptor kinase 1 (atserk1) gene is expressed in developing ovules and early embryos. atserk1 is also transiently expressed during somatic embryogenesis. the predicted atserk1 protein contains an extracellular domain with a leucine zipper motif followed by five leucine-rich repeats, a proline-rich region, a single transmembrane region and an intracellular kinase domain. the atserk1 cdna was fused to two different variants of green fluorescent protei ... | 2001 | 11397085 |
| botrydial is produced in plant tissues infected by botrytis cinerea. | the fungal metabolite botrydial was detected for the first time in ripe fruits of sweet pepper (capsicum annuum) wound-inoculated with conidial suspensions of botrytis cinerea and also in leaves of phaseolus vulgaris and arabidopsis thaliana inoculated without wounding. this phytotoxin was produced in soft rot regions of the infection. in c. annuum, the most aggressive isolate produced the highest botrydial concentrations in planta. the levels of botrydial produced by this isolate did not correl ... | 2001 | 11397435 |
| human biotin-containing subunit of 3-methylcrotonyl-coa carboxylase gene (mcca): cdna sequence, genomic organization, localization to chromosomal band 3q27, and expression. | 3-methylcrotonyl-coa carboxylase (mccase; ec 6.4.1.4) is a mitochondrial biotin enzyme and plays an essential role in the catabolism of leucine and isovalerate in animals, bacterial species, and plants. mccase consists of two subunits, those that are biotin-containing and non-biotin-containing. the genes responsible for these subunits have been isolated in soybean, arabidopsis thaliana, and tomatoes, but not in mammals. in humans, mccase deficiency has been thought to be a rare metabolic disease ... | 2001 | 11401427 |
| cloning of the human mcca and mccb genes and mutations therein reveal the molecular cause of 3-methylcrotonyl-coa: carboxylase deficiency. | 3-methylcrotonyl-coa: carboxylase (ec 6.4.1.4; mcc) deficiency is an inborn error of the leucine degradation pathway (mim *210200) characterized by increased urinary excretion of 3-hydroxyisovaleric acid and 3-methylcrotonylglycine. the clinical phenotypes are highly variable ranging from asymptomatic to profound metabolic acidosis and death in infancy. sequence similarity with glycine max and arabidopsis thaliana genes encoding the two subunits of mcc permitted us to clone the cdnas encoding th ... | 2001 | 11406611 |
| molecular characterization of homologues of both subunits a (spo11) and b of the archaebacterial topoisomerase 6 in plants. | the spo11 protein is an eukaryotic homologue of the topoisomerase 6 subunit a from archaebacteria. in yeast spo11p has been found to bind covalently to double-strand breaks (dsbs) during meiosis. single homologues of the spo11 gene exist in various eukaryotes, except plants. previously, we found in the arabidopsis thaliana genome two ancient paralogs, atspo11-1 and 2. here we report on the molecular characterization of a third one, atspo11-3. this puzzling finding might be explained by the fact ... | 2001 | 11410368 |
| cloning and expression of cdnas encoding alpha1,3-fucosyltransferase homologues from arabidopsis thaliana. | the core alpha1,3-fucosyltransferases are involved in the synthesis of glycans specific to plants and invertebrates which are known to be immunogenic and allergenic. we report the identification, isolation and characterisation of the cdnas of three genes (fucta, fuctb and fuctc) encoding proteins similar to alpha1,3-fucosyltransferases in arabidopsis thaliana. reverse transcription-polymerase chain reaction was used to amplify the full length coding sequence of fucta. the fucta gene, which consi ... | 2001 | 11420147 |
| differential distribution of simple sequence repeats in eukaryotic genome sequences. | complete chromosome/genome sequences available from humans, drosophila melanogaster, caenorhabditis elegans, arabidopsis thaliana, and saccharomyces cerevisiae were analyzed for the occurrence of mono-, di-, tri-, and tetranucleotide repeats. in all of the genomes studied, dinucleotide repeat stretches tended to be longer than other repeats. additionally, tetranucleotide repeats in humans and trinucleotide repeats in drosophila also seemed to be longer. although the trends for different repeats ... | 2001 | 11420357 |
| adenosine 5'-monophosphate inhibits the association of 14-3-3 proteins with the plant plasma membrane h(+)-atpase. | although a well ascertained evidence proves that the activity of the plant plasma membrane h(+)-atpase is regulated by 14-3-3 proteins, information about physiological factors modulating the phosphorylation-dependent association between 14-3-3 proteins and the proton pump is largely incomplete. in this paper we show that the 5'-amp-mimetic, 5-aminoimidazole-4-carboxamide ribonucleoside (aicar), inhibits the fusicoccin-promoted proton extrusion in maize roots. we also demonstrate that 5'-amp inhi ... | 2001 | 11423544 |
| lipoic acid metabolism in arabidopsis thaliana: cloning and characterization of a cdna encoding lipoyltransferase. | lipoic acid is an essential coenzyme required for activity of several key enzyme complexes, such as the pyruvate dehydrogenase complex, in the central metabolism. in these complexes, lipoic acid must be covalently attached to one of the component proteins for it to have biological activity. we report the cloning and characterization of arabidopsis thaliana lip2 cdna for lipoyltransferase that catalyzes the transfer of the lipoyl group from lipoyl-acyl carrier protein to lipoate-dependent enzymes ... | 2001 | 11427685 |
| cyp98a3 from arabidopsis thaliana is a 3'-hydroxylase of phenolic esters, a missing link in the phenylpropanoid pathway. | the 4- and 5-hydroxylations of phenolic compounds in plants are catalyzed by cytochrome p450 enzymes. the 3-hydroxylation step leading to the formation of caffeic acid from p-coumaric acid remained elusive, however, alternatively described as a phenol oxidase, a dioxygenase, or a p450 enzyme, with no decisive evidence for the involvement of any in the reaction in planta. in this study, we show that the gene encoding cyp98a3, which was the best possible p450 candidate for a 3-hydroxylase in the a ... | 2001 | 11429408 |
| cloning of dna encoding a catalytic subunit of snf1-related protein kinase-1 (snrk1-alpha1), and immunological analysis of multiple forms of the kinase, in spinach leaf. | using a pcr approach, we have cloned dna encoding a catalytic subunit isoform (snrk1-alpha1) of snf1-related protein kinase-1 from spinach leaf. the predicted amino acid sequence falls into the snrk1a sub-family, and is closely related to snrk1a sequences expressed in cucumber, arabidopsis thaliana, tobacco and potato. we have generated two affinity-purified antipeptide antibodies (anti-rass and anti-aef) based on the predicted amino acid sequence of spinach snrk1-alpha1. they were used to analy ... | 2001 | 11430435 |
| two cinnamoyl-coa reductase (ccr) genes from arabidopsis thaliana are differentially expressed during development and in response to infection with pathogenic bacteria. | cinnamoyl-coa reductase (ccr; ec 1.2.1.44) catalyses the conversion of cinnamoyl-coas into their corresponding cinnamaldehydes, i.e. the first step of the phenylpropanoid pathway specifically dedicated to the monolignol biosynthetic branch. in previous work, we described the isolation and characterisation of the first cdna encoding ccr in eucalyptus (lacombe, e., hawkins, s., van dorsselaere, j., piquemal, j., goffner, d., poeydomenge, o., boudet, a.m., grima-pettenati, j., 1997. cinnamoyl coa r ... | 2001 | 11430991 |
| identification of novel cyclin-dependent kinases interacting with the cks1 protein of arabidopsis. | the suc1/cks1 proteins interact with cyclin-dependent kinases (cdks) and play an essential, but yet not entirely resolved, role in the regulation of the cell cycle. with the arabidopsis thaliana cks1at protein as bait in a two-hybrid screen, two novel arabidopsis cdks, arath;cdkb1;2 and arath;cdkb2;1, were isolated. a closely related homologue of arath;cdkb2;1 was discovered in the databases and was nominated arath;cdkb2;2. transcript analysis of the five known arath;cdka and arath;cdkb genes re ... | 2001 | 11432958 |
| the arms race is ancient history in arabidopsis, the wildflower. | plant pathology was born after the nineteenth-century potato famine, and since then insightful genetic experiments have contributed to the great progress in our understanding of disease control. our current view of plant resistance focuses on numerous polymorphic resistance loci, which contain genes known as r genes. the complete sequence of the arabidopsis thaliana genome provides a framework for exploring the 'big bang' of r genes that occurred and how r genes evolved in plants from their asso ... | 2001 | 11433358 |
| cream of cytokinin signalling: receptor identified. | cytokinins play a central role in the regulation of plant cell division and numerous developmental processes. pleiotropic effects have made studies of this hormone difficult, and cytokinin signalling pathways have long remained elusive. the recent identification of cre1 (a histidine kinase identical to ahk4 and wol) as the cytokinin receptor of arabidopsis thaliana is a landmark in cytokinin research. mutations have been identified in cre1, and the phenotype of loss-of-function mutations sheds n ... | 2001 | 11435149 |
| characterization of high-molecular-mass allergens in oilseed rape pollen. | oilseed rape pollen allergies have been previously described as the result of cross-sensitization with various pollens. recently, several proteins have been identified as oilseed rape allergens. the aim of the present work was the characterization of oilseed rape pollen allergens by two-dimensional (2-d) gel analysis and amino acid microsequencing. | 2001 | 11435729 |
| isolation and characterization of a na+/h+ antiporter gene from the halophyte atriplex gmelini. | with a homologous gene region we successfully isolated a na+/h+ antiporter gene from a halophytic plant, atriplex gmelini, and named it agnhx1. the isolated cdna is 2607 bp in length and contains one open reading frame, which comprises 555 amino acid residues with a predicted molecular mass of 61.9 kda. the amino acid sequence of the agnhx1 gene showed more than 75% identity with those of the previously isolated nhx1 genes from glycophytes, arabidopsis thaliana and oryza sativa. the migration pa ... | 2001 | 11437248 |
| germ-line transformation of arabidopsis lasiocarpa. | in planta transformation methods have opened up the possibility of transforming plant species for which no regeneration protocols currently exist. in this study, the suitability of the germ-line transformation method developed for arabidopsis thaliana was examined for four taxa in the brassicaceae that have not been previously transformed: arabidopsis griffithiana, arabidopsis lasiocarpa, arabidopsis petraea and capsella bursa-pastoris. numerous transformants were obtained for a. lasiocarpa. tra ... | 2001 | 11437282 |
| a conservative amino acid substitution alters the regiospecificity of cyp94a2, a fatty acid hydroxylase from the plant vicia sativa. | fatty acid omega-hydroxylation is involved in the biosynthesis of the plant cuticle, formation of plant defense signaling molecules, and possibly in the rapid catabolism of free fatty acids liberated under stress conditions. cyp94a2 is a cytochrome p450-dependent medium-chain fatty acid hydroxylase that was recently isolated from vicia sativa. contrary to cyp94a1 and cyp86a1, two other fatty acid hydroxylases previously characterized in v. sativa and arabidopsis thaliana, cyp94a2 is not a strict ... | 2001 | 11437349 |
| functional and conformational properties of the exclusive c-domain from the arabidopsis copper chaperone (cch). | the arabidopsis thaliana copper chaperone (cch) is a small copper binding protein involved in copper trafficking. when compared to homologues from other eukaryotes, cch has two different domains; the conserved n-domain and the plant-exclusive c-domain, a c-terminal extension with an unusual amino-acid composition. in order to characterize this extra c-domain, the cch protein, the n-domain and the c-domain were all expressed separately in heterologous systems. while the n-domain retained the copp ... | 2001 | 11439106 |
| arabidopsis uvh3 gene is a homolog of the saccharomyces cerevisiae rad2 and human xpg dna repair genes. | to identify mechanisms of dna repair in arabidopsis thaliana, we have analyzed a mutant (uvh3) which exhibits increased sensitivity to ultraviolet (uv) light, h2o2 and ionizing radiation and displays a premature senescence phenotype. the uvh3 locus was mapped within chromosome iii to the gl1 locus. a cosmid contig of the gl1 region was constructed, and individual cosmids were used to transform uvh3 mutant plants. cosmid n9 was found to confer uv-resistance, h2o2-resistance and a normal senescenc ... | 2001 | 11439121 |
| antisense inhibition of protein phosphatase 2c accelerates cold acclimation in arabidopsis thaliana. | two related protein phosphatases 2c, abi1 and atpp2ca have been implicated as negative regulators of aba signalling. in this study we characterized the role of atpp2ca in cold acclimation. the pattern of expression of atpp2ca and abi1 was studied in different tissues and in response to abiotic stresses. the expression of both atpp2ca and abi1 was induced by low temperature, drought, high salt and aba. the cold and drought-induced expression of these genes was aba-dependent, but divergent in vari ... | 2001 | 11439132 |
| resistance to pseudomonas syringae conferred by an arabidopsis thaliana coronatine-insensitive (coi1) mutation occurs through two distinct mechanisms. | a new allele of the coronatine-insensitive locus (coi1) was isolated in a screen for arabidopsis thaliana mutants with enhanced resistance to the bacterial pathogen pseudomonas syringae. this mutant, designated coi1-20, exhibits robust resistance to several p. syringae isolates but remains susceptible to the virulent pathogens erisyphe and cauliflower mosaic virus. resistance to p. syringae strain pstdc3000 in coi1-20 plants is correlated with hyperactivation of pr-1 expression and accumulation ... | 2001 | 11439137 |
| molecular cloning and characterization of peroxiredoxin from toxoplasma gondii. | a cdna of 1.1 kb comprising the gene encoding the peroxiredoxin of toxoplasma gondii (tgprx) has been cloned. the open reading frame of 591 bp was translated into a protein of 196 amino acids with a molecular mass of 25 kda. conserved 2 cysteine domains of phe-val-cys-pro and glu-val-cys-pro indicated tgprx belonged to 2-cys prx families. tgprx showed the highest homology with that of arabidopsis thaliana by 53.9% followed by entamoeba histolytica with 39.5% by the amino acid sequence alignment. ... | 2001 | 11441500 |
| promoter analysis of the nuclear gene encoding the chloroplast glyceraldehyde-3-phosphate dehydrogenase b subunit of arabidopsis thaliana. | the promoter of the nuclear gene, gapb, which encodes the b subunit of chloroplast glyceraldehyde-3-phosphate dehydrogenase (gadph) of arabidopsis thaliana, was previously shown to contain four direct repeats (gap boxes, located between -237 and -181) that were necessary but not sufficient for light-activated gene transcription. to identify additional elements located between the gap boxes and tata box, various gapb promoter fragments driving the beta-glucuronidase (gus) reporter gene were const ... | 2001 | 11442054 |
| an upstream region of the arabidopsis thaliana cdka;1 (cdc2aat) gene directs transcription during trichome development. | the cell cycle of eukaryotes is tightly regulated through the activity of cyclin-dependent kinases. the arabidopsis thaliana cdka;1 (cdc2aat) gene is thought to encode such a protein kinase, since it is actively transcribed in proliferating tissues and can complement defects in the schizosaccharomyces pombe cdc2 gene. we analyzed the functional structure of the cdka;1 promoter, using fusion genes between various upstream regions of cdka;1 and the escherichia coli beta-glucuronidase (gus) gene. a ... | 2001 | 11442060 |
| identification and characterization of sppa, a novel light-inducible chloroplast protease complex associated with thylakoid membranes. | a new component of the chloroplast proteolytic machinery from arabidopsis thaliana was identified as a sppa-type protease. the sequence of the mature protein, deduced from a full-length cdna, displays 22% identity to the serine-type protease iv (sppa) from escherichia coli and 27% identity to synechocystis sppa1 (sll1703) but lacks the putative transmembrane spanning segments predicted from the e. coli sequence. the n-terminal sequence exhibits typical features of a cleavable chloroplast stroma- ... | 2001 | 11443110 |
| construction of a 1.2-mb contig including the citrus tristeza virus resistance gene locus using a bacterial artificial chromosome library of poncirus trifoliata (l.) raf. | the citrus tristeza virus resistance gene (ctv) is a single dominant gene in poncirus trifoliata, a sexually compatible relative of citrus. to clone this gene, a bacterial artificial chromosome (bac) library has been constructed from an individual plant that was homozygous for ctv. this library contains 45,696 clones with an average insert size of 80 kb, corresponding to 9.6 genome equivalents. screening of the bac library with five chloroplast dna probes indicated that 0.58% of the bac clones c ... | 2001 | 11444697 |
| atbs14a and atbs14b, two bet1/sft1-like snares from arabidopsis thaliana that complement mutations in the yeast sft1 gene. | snares are membrane-associated proteins that play a central role in vesicle targeting and intra-cellular membrane fusion reactions in eukaryotic cells. here we describe the identification of atbs14a and atbs14b, putative snares from arabidopsis thaliana that share 60% amino acid sequence identity. both atbs14a and bs14b are dosage suppressors of the temperature-sensitive growth defect in sft1-1 cells and over-expression of either atbs14a or atbs14b can support the growth of sft1delta cells but n ... | 2001 | 11445081 |
| loss of stress-induced expression of catalase3 during leaf senescence in arabidopsis thaliana is restricted to oxidative stress. | different stress conditions can induce changes in the activity of the antioxidant enzymes superoxide dismutase (sod, ec 1.15.1.1), ascorbate peroxidase (apx, ec 1.11.1.11) and catalase (cat, ec 1.11.1.6). the enzyme activities of all sod and apx isoforms detected in young arabidopsis leaves remained unaffected or slightly decreased after moderate paraquat treatment. while cat2 activity also remained unaffected under these conditions, cat3 enzyme activity was enhanced. in contrast to the enzyme a ... | 2001 | 11448761 |
| hal1 mediate salt adaptation in arabidopsis thaliana. | the yeast hal1 gene was introduced into arabidopsis thaliana by agrobacterium tumefaciens-mediated transformation with vacuum infiltration under the control of camv 35s promoter. thirty-three individual kanamycin resistant plants were obtained from 75,000 seeds. southern blotting analysis indicated that hal1 gene had been integrated into all of the transgenic plants' genomes. the copy number of hal1 gene in transgenic plants was mostly 1 to 3 by southern analysis. phenotypes of transgenic plants ... | 2001 | 11453546 |
| overexpression of a heterologous sam gene encoding s-adenosylmethionine synthetase in flax (linum usitatissimum) cells: consequences on methylation of lignin precursors and pectins. | the arabidopsis thaliana sam1 gene encoding s-adenosylmethionine synthetase (ec 2.5.1.6) was transferred to flax (linum usitatissimum) cells via agrobacterium tumefaciens. this enzyme catalyses the conversion of methionine to s-adenosylmethionine (sam), the major methyl group donor in living cells. the aim of this work was to study the consequences of an increased sam-synthetase (sam-s) activity in transgenic cell lines on both the production of mono- and dimethoxylated lignin monomers and the d ... | 2001 | 11454228 |
| quantitative and reproducible two-dimensional gel analysis using phoretix 2d full. | quantitative two-dimensional polyacrylamide gel electrophoresis (2-d page) is used to determine changes in individual protein levels in complex protein mixtures. to provide reliable data, the software used for 2-d gel image analysis must provide a linear response over a wide dynamic range of data output. here, we show that phoretix 2d full analysis of 2-d gels stained with colloidal coomassie brilliant blue g-250 can provide a linear measure of changes in protein quantity. we show using a comple ... | 2001 | 11465508 |
| regulation of the plant-type 5'-adenylyl sulfate reductase by oxidative stress. | 5'-adenylyl sulfate (aps) reductase (ec 1.8.4.9) catalyzes a key reaction in the plant sulfate assimilation pathway leading to the synthesis of cysteine and the antioxidant glutathione. in arabidopsis thaliana aps reductase is encoded by a family of three genes. in vitro biochemical studies revealed that the enzyme product derived from one of them (apr1) is activated by oxidation, probably through the formation of a disulfide bond. the apr1 enzyme is 45-fold more active when expressed in a trxb ... | 2001 | 11467967 |
| identification of 66 box c/d snornas in arabidopsis thaliana: extensive gene duplications generated multiple isoforms predicting new ribosomal rna 2'-o-methylation sites. | dozens of box c/d small nucleolar rnas (snornas) have recently been found in eukaryotes (vertebrates, yeast), ancient eukaryotes (trypanosomes) and archae, that specifically target ribosomal rna sites for 2'-o-ribose methylation. although early biochemical data revealed that plant rrnas are among the most highly ribomethylated in eukaryotes, only a handful of methylation guide snornas have been characterized in this kingdom. we report 66 novel box c/d snornas identified by computational screenin ... | 2001 | 11469857 |
| identification of human asf1 chromatin assembly factors as substrates of tousled-like kinases. | first described in arabidopsis thaliana, tousled-like kinases (tlks) are highly conserved in both plants and animals. in plants, tousled kinase is essential for proper flower and leaf development, but no direct functional link to any other plant gene product has yet been established. likewise, the role of tlks in animals is unknown. in human cells, two structurally similar tlks, tlk1 and tlk2, were recently shown to be cell cycle-regulated kinases with maximal activities during s phase. here, we ... | 2001 | 11470414 |
| kinesins in the arabidopsis genome: a comparative analysis among eukaryotes. | kinesins constitute a superfamily of microtubule motor proteins that are found in eukaryotic organisms. members of the kinesin superfamily perform many diverse cellular functions such as transport of vesicles and organelles, spindle formation and elongation, chromosome segregation, microtubule dynamics and morphogenesis. only a few kinesins have been characterized in plants including arabidopsis thaliana. because of the diverse cellular functions in which kinesins are involved, the number, types ... | 2001 | 11472632 |
| the promoter of a cytosolic glutamine synthetase gene from the conifer pinus sylvestris is active in cotyledons of germinating seeds and light-regulated in transgenic arabidopsis thaliana. | we have isolated and characterized a genomic clone encoding scots pine (pinus sylvestris) cytosolic glutamine synthetase (gs). the clone contains the 5' end half of the gene including part of the coding region and 980 bp upstream of the translation initiation codon. the major transcription start site (+1) was mapped around 180 nucleotides upstream of the translation initiation codon. sequence analysis of the 5'-upstream region of the gene reveals the presence of putative regulatory elements incl ... | 2001 | 11473696 |
| the ahk4 gene involved in the cytokinin-signaling pathway as a direct receptor molecule in arabidopsis thaliana. | we previously identified a set of structurally related genes, ahk2, 3 and 4, each encoding a sensor histidine kinase in arabidopsis thaliana. to determine the relevant biological functions, we identified a loss-of-function mutation of the ahk4 gene. the mutant exhibited the cytokinin-resistant phenotype not only in inhibition of root growth by cytokinin but also in greening and shoot induction of calli. moreover, ahk4 expressed in budding yeast showed histidine kinase activity in a manner depend ... | 2001 | 11479382 |
| functional activity and role of cation-efflux family members in ni hyperaccumulation in thlaspi goesingense. | the ability of thlaspi goesingense to hyperaccumulate ni seems to be governed in part by enhanced accumulation of ni within leaf vacuoles. we have characterized genes from t. goesingense encoding putative vacuolar metal ion transport proteins, termed metal tolerance proteins (tgmtps). these proteins contain all of the features of cation-efflux family members, and evidence indicates they are derived from a single genomic sequence (tgmtp1) that gives rise to an unspliced (tgmtp1t1) and a spliced ( ... | 2001 | 11481436 |
| the 3' non-coding region of a c4 photosynthesis gene increases transgene expression when combined with heterologous promoters. | the me1 gene of the dicot flaveria bidentis encodes nadp malic enzyme, which catalyses the decarboxylation reaction of c4 photosynthesis in bundle sheath cells. we have previously shown that the 3' non-coding region (me1 3') controls quantitative expression of the gene. we wondered whether me1 3' can increase expression when combined with heterologous promoters. we tested a highly expressed, constitutive promoter, the s4 promoter from subterranean clover stunt virus, and a highly expressed, leaf ... | 2001 | 11488479 |
| molecular and catalytic properties of arabidopsis thaliana adenylyl sulfate (aps)-kinase. | a cdna clone (atakn1) from arabidopsis thaliana encoding aps-kinase (ec 2.7.1.25) was investigated for structural and catalytic properties of the gene product. recombinant his10-atakn1 formed paps at a vmax of 7.35 u x mg(-1). the km for aps was 0.14 microm and for atp 147 microm. aps caused a severe substrate inhibition (k(i) 4.5 microm). the type of inhibition is uncompetitive with respect to mgatp. high ionic strength and reducing thiols stabilized the enzyme activity. plant aps-kinase is reg ... | 2001 | 11488606 |
| an arabidopsis inositol phospholipid kinase strongly expressed in procambial cells: synthesis of ptdins(4,5)p2 and ptdins(3,4,5)p3 in insect cells by 5-phosphorylation of precursors. | we have cloned a phosphatidylinositol-4-phosphate 5-kinase (pip5k) cdna (atp5k1) from arabidopsis thaliana. by the application of cell permeabilization and short-term nonequilibrium labelling we show that expression of atp5k1 in baculovirus-infected insect (spodoptera frugiperda) cells directs synthesis of ptdins(4,5)p2 and ptdins(3,4,5)p3. the same phosphoinositides were produced by isolated whole-cell membrane fractions of atp5k1-expressing insect cells. their synthesis was not affected by add ... | 2001 | 11489170 |
| gene-associated cpg islands in plants as revealed by analyses of genomic sequences. | we screened plant genome sequences, primarily from rice and arabidopsis thaliana, for cpg islands, and identified dna segments rich in cpg dinucleotides within these sequences. these cpg-rich clusters appeared in the analysed sequences as discrete peaks and occurred at the frequencies of one per 4.7 kb in rice and one per 4.0 kb in a. thaliana. in rice and a. thaliana, most of the cpg-rich clusters were associated with genes, which suggests that these clusters are useful landmarks in genome sequ ... | 2001 | 11489175 |
| physical interactions between aba response loci of arabidopsis. | genetic and physiological studies have shown that the arabidopsis thaliana abscisic acid-insensitive (abi) loci interact to regulate seed-specific and/or aba-inducible gene expression. we have used the yeast two-hybrid assay to determine whether any of these genetic interactions reflect direct physical interactions. by this criterion, only abi3 and abi5 physically interact with each other, and abi5 can form homodimers. the b1 domain of abi3 is essential for this interaction; this is the first sp ... | 2001 | 11489176 |
| the protein kinases atmap3kepsilon1 and bnmap3kepsilon1 are functional homologues of s. pombe cdc7p and may be involved in cell division. | we identified an arabidopsis thaliana gene, atmap3kepsilon1, and a brassica napus cdna, bnmap3kepsilon1, encoding functional protein serine/threonine kinases closely related to cdc7p and cdc15p from schizosaccharomyces pombe and saccharomyces cerevisiae, respectively. this is the first report of cdc7-related genes in non-fungal eukaryotes; no such genes have as yet been identified in metazoans. the b. napus protein is able to partially complement a cdc7 loss of function mutation in s. pombe. rt- ... | 2001 | 11489177 |
| the dictyostelium homologue of mammalian soluble adenylyl cyclase encodes a guanylyl cyclase. | a new dictyostelium discoideum cyclase gene was identified that encodes a protein (sgc) with 35% similarity to mammalian soluble adenylyl cyclase (sac). gene disruption of sgc has no effect on adenylyl cyclase activity and results in a >10-fold reduction in guanylyl cyclase activity. the scg- null mutants show reduced chemotactic sensitivity and aggregate poorly under stringent conditions. with mn(2+)/gtp as substrate, most of the sgc activity is soluble, but with the more physiological mg(2+)/g ... | 2001 | 11500361 |
| cloning and characterisation of chlorophyll synthase from avena sativa. | the chlorophyll synthase gene from oat (avena sativa) was cloned and expressed in escherichia coli. the deduced amino acid sequence consists of 378 amino acids including a presequence of 46 amino acids. deletion mutants show that a core protein comprising amino acid residues 88 to 377 is enzymatically active. the sequence of the mature protein shows 85% identity with the chlorophyll synthase of arabidopsis thaliana and 62% identity with the chlorophyll synthase of synechocystis pcc 6803. the gen ... | 2001 | 11501754 |
| purification of chrysancorin, a novel antifungal protein with mitogenic activity from garland chrysanthemum seeds. | a novel antifungal protein, designated chrysancorin, was isolated from seeds of chrysanthemum coronarium var. spatiosum with a procedure involving ion exchange chromatography on deae-cellulose, affinity chromatography on affi-gel blue resin, ion exchange chromatography on sp-sepharose and fplc-gel filtration on superdex 75. the n-terminus of chrysancorin displays sequence similarity to the genomic sequence of chromosome 1 from arabidopsis thaliana bac t19e23. chrysancorin exhibits a molecular ma ... | 2001 | 11501760 |
| role of threonines in the arabidopsis thaliana somatic embryogenesis receptor kinase 1 activation loop in phosphorylation. | the arabidopsis thaliana somatic embryogenesis receptor kinase 1 (atserk1) gene encodes a receptor-like protein kinase that is transiently expressed during embryogenesis. to determine the intrinsic biochemical properties of the atserk1 protein, we have expressed the intracellular catalytic domain as a glutathione s-transferase fusion protein in escherichia coli. the atserk1-glutathione s-transferase fusion protein mainly autophosphorylates on threonine residues (k(m) for atp, 4 x 10(-6) m), and ... | 2001 | 11509554 |
| cloning and characterization of a cdna encoding beta-amyrin synthase involved in glycyrrhizin and soyasaponin biosyntheses in licorice. | an oxidosqualene cyclase cdna, termed ggbas1, was isolated from cultured cells of licorice (glycyrrhiza glabra) by heterologous hybridization with cdna of arabidopsis thaliana lup1 lupeol synthase. the yeast transformed with an expression vector containing the open reading frame of ggbas1 produced beta-amyrin, indicating that ggbas1 encodes beta-amyrin synthase involved in the glycyrrhizin and soyasaponin biosyntheses in licorice. northern blot analysis showed that the level of beta-amyrin synth ... | 2001 | 11510484 |
| a conserved myb transcription factor involved in phosphate starvation signaling both in vascular plants and in unicellular algae. | plants have evolved a number of adaptive responses to cope with growth in conditions of limited phosphate (pi) supply involving biochemical, metabolic, and developmental changes. we prepared an ems-mutagenized m(2) population of an arabidopsis thaliana transgenic line harboring a reporter gene specifically responsive to pi starvation (atips1::gus), and screened for mutants altered in pi starvation regulation. one of the mutants, phr1 (phosphate starvation response 1), displayed reduced response ... | 2001 | 11511543 |
| isolation of a novel g-protein gamma-subunit from arabidopsis thaliana and its interaction with gbeta. | there is increasing evidence that heterotrimeric g-proteins (g-proteins) are involved in many plant processes including phytohormone response, pathogen defence and stomatal control. in animal systems, each of the three g-protein subunits belong to large multigene families; however, few subunits have been isolated from plants. here we report the cloning of a second plant g-protein gamma-subunit (agg2) from arabidopsis thaliana. the predicted agg2 protein sequence shows 48% identity to the first i ... | 2001 | 11513956 |
| a novel plastid-targeted j-domain protein in arabidopsis thaliana. | arabidopsis cdnas encoding atj11, the smallest known j-domain protein, have been isolated and characterized. the precursor protein of 161 amino acid residues was synthesized in vitro and imported by isolated pea chloroplasts where it was localized to the stroma and cleaved to a mature protein of 125 amino acid residues. the mature protein consists of an 80 amino acid j-domain, and n- and c-terminal extensions of 24 and 21 amino acid residues, respectively, which show no similarity to regions in ... | 2001 | 11516154 |
| analysis of an essential requirement for the poly(a) binding protein function using cross-species complementation. | poly(a) binding protein (pabp) is an essential, well-conserved, multifunctional protein involved in translational initiation, mrna biogenesis, and degradation [1--5]. we have used a cross-species complementation approach to address the nature of the essential requirement for pabp in yeast. the expression of pab3p, a member of the arabidopsis thaliana pabp multigene family, rescues the lethal phenotype associated with the loss of the yeast pab1p. however, pab3p neither protects the mrna 5' cap fr ... | 2001 | 11516954 |
| mutations in the 3beta-hydroxysterol delta24-reductase gene cause desmosterolosis, an autosomal recessive disorder of cholesterol biosynthesis. | desmosterolosis is a rare autosomal recessive disorder characterized by multiple congenital anomalies. patients with desmosterolosis have elevated levels of the cholesterol precursor desmosterol, in plasma, tissue, and cultured cells; this abnormality suggests a deficiency of the enzyme 3beta-hydroxysterol delta24-reductase (dhcr24), which, in cholesterol biosynthesis, catalyzes the reduction of the delta24 double bond of sterol intermediates. we identified the human dhcr24 cdna, by the similari ... | 2001 | 11519011 |
| trehalose metabolism in arabidopsis: occurrence of trehalose and molecular cloning and characterization of trehalose-6-phosphate synthase homologues. | axenically grown arabidopsis thaliana plants were analysed for the occurrence of trehalose. using gas chromatography-mass spectrometry (gc-ms) analysis, trehalose was unambiguously identified in extracts from arabidopsis inflorescences. in a variety of organisms, the synthesis of trehalose is catalysed by trehalose-6-phosphate synthase (tps; ec 2.4.1.15) and trehalose-6-phosphate phosphatase (tpp; ec 3.1.3.12). based on est (expressed sequence tag) sequences, three full-length arabidopsis cdnas ... | 2001 | 11520870 |
| developmental analysis of a putative atp/adp carrier protein localized on glyoxysomal membranes during the peroxisome transition in pumpkin cotyledons. | in order to clarify the peroxisomal membrane proteins (pmps), we characterized one of the major pmps, pmp38. the deduced amino acid sequence for its cdna in arabidopsis thaliana contained polypeptides with 331 amino acids and had high similarity with those of homo sapiens pmp34 and candida boidinii pmp47 known as homologues of mitochondrial atp/adp carrier protein. we expected pmp38 to be localized on peroxisomal membranes, because it had the membrane peroxisomal targeting signal. cell fractiona ... | 2001 | 11522909 |
| enzymatic characterization of the recombinant arabidopsis thaliana nitrilase subfamily encoded by the nit2/nit1/nit3-gene cluster. | three of the nitrilase isoenzymes of arabidopsis thaliana (l.) heynh. are located on chromosome iii in tandem and these genes (nit2/nit1/nit3 in the 5'-->3' direction) encode highly similar polypeptides. copy dnas encompassing the entire coding sequences for all three nitrilases were expressed in escherichia coli as fusion proteins containing a c-terminal hexahistidine extension. all three nitrilases were obtained as enzymatically active proteins, and their characteristics were determined, inclu ... | 2001 | 11525507 |
| a hemoglobin from plants homologous to truncated hemoglobins of microorganisms. | we have identified a nuclear-encoded hb from plants (glb3) that has a central domain similar to the "truncated" hbs of bacteria, protozoa, and algae. the three-dimensional structure of these hbs is a 2-on-2 arrangement of alpha-helices, distinct from the 3-on-3 arrangement of the standard globin fold [pesce, a., couture, m., dewilde, s., guertin, m., yamauchi, k., ascenzi, p., moens, l. & bolognesi, m. (2000) embo j. 19, 2424-2434]. glb3-like genes are not found in animals or yeast, but our anal ... | 2001 | 11526234 |
| an essential role of a tatc homologue of a delta ph- dependent protein transporter in thylakoid membrane formation during chloroplast development in arabidopsis thaliana. | at least three transport systems function in targeting nuclear-encoded chloroplast proteins to the chloroplast thylakoid membrane. one of these systems requires a thylakoid ph gradient and is named the deltaph-dependent protein transport system. a similar deltaph export system of escherichia coli contains four components, twin arginine translocation a (tata), tatb, tatc, and tate. tatc is a major component of the deltaph-dependent protein transporter in e. coli and functions in the translocation ... | 2001 | 11526245 |
| biolistic transformation of arabidopsis root hairs: a novel technique to facilitate map-based cloning. | the final stage of map-based gene isolation is complementation of the mutant phenotype with wild-type dna to determine the exact location of the gene of interest. this usually involves agrobacterium tumefaciens-mediated transformation, which is reliable and produces stable transformants. however, the process of agrobacterium transformation may take up to three months to complete. if the mutant phenotype can be seen in a single cell, and the wild-type copy of the gene can act cell autonomously, t ... | 2001 | 11532182 |
| a clustering method for repeat analysis in dna sequences. | a computational system for analysis of the repetitive structure of genomic sequences is described. the method uses suffix trees to organize and search the input sequences; this data structure has been used previously for efficient computation of exact and degenerate repeats. | 2001 | 11532211 |
| ara6, a plant-unique novel type rab gtpase, functions in the endocytic pathway of arabidopsis thaliana. | ara6 of arabidopsis thaliana is a novel member of the rab/ypt gtpase family with unique structural features. it resembles rab5 gtpases best, but lacks a large part of the c-terminal hypervariable region and the cysteine motif, and instead harbors an extra stretch of amino acid residues containing myristoylation and palmitoylation sites at the n-terminus. ara6 is tightly associated with membranes and is expressed constitutively. in contrast, the conventional rab5 ortholog, ara7, is highly express ... | 2001 | 11532937 |
| multiple forms of formamidopyrimidine-dna glycosylase produced by alternative splicing in arabidopsis thaliana. | formamidopyrimidine-dna glycosylase (fpg) catalyzes the initial steps in the repair of dna containing oxidized purines. two cdna clones from arabidopsis thaliana encoding homologs of bacterial fpg have previously been described. we now report that there are at least five additional variants of fpg mrna in arabidopsis, each apparently produced from the same gene (atmmh) by alternative splicing. thus, atmmh, like at least four other genes in the base excision repair pathway of human cells, produce ... | 2001 | 11535407 |
| experiment "seeds" on biokosmos 9. dosimetric part. | the aim of the experiment "seeds" on the sowjetic satellite biokosmos 9 was the observation of mutagenic effects caused at special loci of seeds of arabidopsis thaliana and assigned to particles of the cosmic radiation. two types of exposure units were flown: a low-shielding unit type i, mounted at the surface of the satellite (1.4 g/cm2 shielding) and, for comparison, an identical item inside (16 g/cm2 shielding), using nuclear emulsion as track detectors. a type ii unit, flown inside (18g/c ... | 1992 | 11537029 |
| early and late damages induced by heavy charged particle irradiation in embryonic tissue of arabidopsis seeds. | early and late effects of accelerated heavy ions (hze) on the embryonic tissue of arabidopsis thaliana seeds were investigated seeing that initial cells of the plant eumeristems resemble the original cells of animal and human tissues with continuous cell proliferation. the endpoints measured were lethality and tumorization in the m1-generation for early effects and embryonic lethality in the m2-generation for late effects. the biological endpoints are plotted as functions of the physical paramet ... | 1989 | 11537283 |
| time threshold for second positive phototropism is decreased by a preirradiation with red light. | a second positive phototropic response is exhibited by a plant after the time of irradiation has exceeded a time threshold. the time threshold of dark-grown seedlings is about 15 minutes for arabidopsis thaliana. this threshold is decreased to about 4 minutes by a 669-nanometer preirradiation. tobacco (nicotiana tabacum) seedlings show a similar response. the time threshold of dark-grown seedlings is about 60 minutes for tobacco, and is decreased to about 15 minutes after a preirradiation wi ... | 1992 | 11537887 |
| cosmic ionizing radiation effects in plant seeds after short and long duration exposure flights. | recently, comparison of biophysical data obtained from orbital flights of short and long duration led to results which will be significant for long and/or repeated stay of man in space. under orbital conditions biological stress is induced in dry seeds of arabidopsis thaliana by cosmic radiation especially its high energetic, densely ionizing component, the heavy ions (hze). for comparison of radiation impact during different space flights a biological attempt at estimating the impact of singl ... | 1994 | 11539941 |
| first radiobiological results of ldef-1 experiment a0015 with arabidopsis seed embryos and sordaria fungus spores. | this article highlights the first results of investigations on the general vitality and damage endpoints caused by cosmic ionizing radiation in dry, dormant plant seeds of the crucifer plant arabidopsis thaliana (l.) heynh. and the ascomycete sordaria fimicola after 69 month stay in space. wild-type and mutant gene marker lines were included in free flyer biostack containers and exposed on earth and side tray of the ldef-1 satellite. the damage in biological endpoints observed in the seeds inc ... | 1994 | 11539984 |