检索结果-内蒙古大学图书馆

D-Tyrosyl-tRNA^Tyr metabolism in Saccharomyces cerevisiae

JOURNAL OF BIOLOGICAL CHEMISTRY 2000年第16期275卷 11626-11630页

作者： Soutourina, J Blanquet, S Plateau, P Ecole Polytech CNRS Biochim Lab Unite Mixte Rech 7654 F-91128 Palaiseau France

The Saccharomyces cerevisiae YDL219w (DTD1) gene, which codes for an amino acid sequence sharing 34% identity with the Escherichia coli D-Tyr-tRNA(Tyr) deacylase, was cloned, and its product was functionally characterized. Overexpression in the yeast of the DTD1 gene from a multicopy plasmid increased D-Tyr-tRNA(Tyr) deacylase activity in crude extracts by two orders of magnitude. Upon disruption of the chromosomal gene, deacylase activity was decreased by more than 90%, and the sensitivity to D-tyrosine of the growth of S. cerevisiae was exacerbated. The toxicity of D-tyrosine was also enhanced under conditions of nitrogen starvation, which stimulate the uptake of D-amino acids. In relation with these behaviors, the capacity of purified S. cerevisiae tyrosyl-tRNA synthetase to produce D-Tyr-tRNA(Tyr) could be shown. Finally, the phylogenetic distribution of genes homologous to DTD1 was examined in connection with L-tyrosine prototrophy or auxotrophy. In the auxotrophs, DTD1-like genes are systematically absent. In the prototrophs, the putative occurrence of a deacylase is variable. It possibly depends on the L-tyrosine anabolic pathway adopted by the cell.

关键词：碱基序列克隆分子大肠杆菌/遗传学大肠杆菌/生长和发育大肠杆菌/代谢基因文库分子序列数据聚合酶链反应 RNA 转移酪氨酸/遗传学 RNA 转移酪氨酸/代谢酿酒酵母菌/遗传学酿酒酵母菌/生长和发育酿酒酵母菌/代谢软件酪氨酸/代谢酪氨酸tRNA连接酶/代谢

来源：评论

学校读者我要写书评

暂无评论

Use of flow cytometry to monitor cell damage and predict fermentation activity of dried yeasts

引用

JOURNAL OF APPLIED MICROBIOLOGY 2000年第2期89卷 207-214页

作者： Attfield, PV Kletsas, S Veal, DA van Rooijen, R Bell, PJL Macquarie Univ Dept Biol Sci Ctr Fluorimetr Applicat Biotechnol Sydney NSW 2109 Australia DSM Bakery Ingredients Technol Delft Netherlands

Viable dried yeast is used as an inoculum for many fermentations in the baking and wine industries. The fermentative activity of yeast in bread dough or grape must is a critical parameter of process efficiency. Here, it is shown that fluorescent stains and flow cytometry can be used in concert to predict the abilities of populations of dried bakers' and wine yeasts to ferment after rehydration. Fluorescent dyes that stain cells only if they have damaged membrane potential (oxonol) or have increased membrane permeability (propidium iodide) were used to analyse, by flow cytometry, populations of rehydrated yeasts. A strong relationship (r(2) = 0.99) was found between the percentages of populations staining with the oxonol and the degree of cell membrane damage as measured by the more traditional method of leakage of intracellular compounds. There were also were good negative relationships (r(2) greater than or equal to 0.83) between fermentation by rehydrated bakers' or wine dry yeasts and percentage of populations staining with either oxonol or propidium iodide. Fluorescent staining with flow cytometry confirmed that factors such as vigour of dried yeast mixing in water, soaking before stirring, rehydration in water or fermentation medium and temperature of rehydration have profound effects on subsequent yeast vitality. These experiments indicate the potential of flow cytometry as a rapid means of predicting the fermentation performance of dried bakers' and wine yeasts.

关键词：集落计数微生物干燥法发酵流式细胞术荧光荧光染料/代谢热温度酿酒酵母菌/生长和发育酿酒酵母菌/代谢染色与标记

来源：评论

学校读者我要写书评

暂无评论

Maize cap1 encodes a novel SERCA-type calcium-ATPase with a calmodulin-binding domain

引用

JOURNAL OF BIOLOGICAL CHEMISTRY 2000年第28期275卷 21678-21687页

作者： Subbaiah, CC Sachs, MM Univ Illinois Dept Crop Sci Urbana IL 61801 USA ARS USDA Soybean Maize Germplasm Pathol & Genet Unit Urbana IL 61801 USA

A cDNA (CAP1) isolated from maize roots shares sequence identity with genes encoding P-type Ca2+-ATPases and restores the growth phenotype of yeast mutants defective in Ca2+-pumps. CAP1 was transcribed and translated in the yeast mutant. Furthermore, the membrane-integrated product formed a Ca2+-dependent phosphorylated intermediate and supported Ca2+ transport. Although CAP1 shares greater sequence identity with mammalian "endoplasmic reticulum-type" Ca2+-pumps, it differs from these genes by having features of calmodulin (CaM)-regulated Ca2+-pumps. CAP1 from yeast microsomes bound CaM, and the CAP1-dependent Ca2+ transport in yeast was stimulated by CaM. Peptides from the C terminus of CAP1 bound CaM. Anti-CAP1 antibodies specifically recognized a maize microsomal polypeptide that also bound CaM. A similar polypeptide also formed a Ca2+-dependent phosphoenzyme. Our results suggest that cap1 encodes a novel form of CaM-regulated Ca2+-ATPase in maize. CAP1 appears to be encoded by one or two genes in maize. CAP1 RNA is induced only during early anoxia, indicating that the Ca2+-pump may play an important role in O-2-deprived maize cells.

关键词：氨基酸序列结合部位钙转运ATP酶类/化学钙转运ATP酶类/遗传学钙转运ATP酶类/代谢钙调蛋白/代谢克隆分子大肠杆菌动力学分子序列数据植物蛋白质类植物根/酶学蛋白质生物合成重组蛋白质类/化学重组蛋白质类/代谢酿酒酵母菌/生长和发育序列比对序列同源性氨基酸转录遗传玉米/酶学玉米/遗传学

来源：评论

学校读者我要写书评

暂无评论

Novel RING finger proteins, Air1p and Air2p, interact with Hmt1p and inhibit the arginine methylation of Npl3p

引用

JOURNAL OF BIOLOGICAL CHEMISTRY 2000年第42期275卷 32793-32799页

作者： Inoue, K Mizuno, T Wada, K Hagiwara, M Tokyo Med & Dent Univ Med Res Inst Dept Funct Genom Bunkyo Ku Tokyo 1138510 Japan Yamanouchi Pharmaceut Co Ltd Inst Drug Discovery Res SEEDS Lab Tsukuba Ibaraki 3058585 Japan

Heterogeneous nuclear ribonucleoproteins (hnRNPs) are involved in the mRNA processing and export and are post-translationally modified by methylation at arginine residues in their arginine-glycine-rich (RGG) domains. We screened the factors that can interact with the RGG domain of Np13p only in the presence of Hmt1p with the two-hybrid system in Saccharomyces cerevisiae, An isolated clone, YIL079, encodes a novel RING finger protein that was not directly bound to Np13p but associated with the N terminus of Hmt1p. Thus, we designated the gene product Air1p (arginine methyltransferase-interacting RING finger protein). Air1p inhibited the Hmt1p-mediated methylation of Np13p in vitro. Overexpression of Air1p repressed the Hmt1p-dependent growth of cells. Since homology searches indicate that the YDL175 gene product has significant identity (45%) with Air1p, we designated the gene AIR2. Air2p also has a RING finger domain and was bound to Hmt1p. Although single disruption of either gene gave no effect on the cell growth, cells lacking Air1p and Air2p grew at an extremely slow rate with accumulated poly(A)(+) RNA in the nucleus. Thus, Air1p and Air2p may affect mRNA transport by regulating the arginine methylation state of heterogeneous nuclear ribonucleoproteins.

关键词： ATP结合匣式转运子/化学 ATP结合匣式转运子/代谢衔接蛋白质类信号转导氨基酸序列精氨酸碱基序列载体蛋白质类/化学载体蛋白质类/遗传学载体蛋白质类/代谢克隆分子 DNA引物真菌蛋白质类/化学真菌蛋白质类/代谢基因型甲基化分子序列数据诱变定点核蛋白质类/化学核蛋白质类/代谢蛋白质精氨酸N-甲基转移酶 RNA结合蛋白质类重组蛋白质类/化学重组蛋白质类/代谢阻遏蛋白质类酿酒酵母菌/遗传学酿酒酵母菌/生长和发育酿酒酵母菌/代谢酿酒酵母蛋白质类序列比对序列同源性氨基酸锌指

来源：评论

学校读者我要写书评

暂无评论

ASC1/RAS2 suppresses the growth defect on glycerol caused by the atp1-2 mutation in the yeast Saccharomyces cerevisiae

引用

JOURNAL OF BIOLOGICAL CHEMISTRY 2000年第14期275卷 10492-10497页

作者： Mabuchi, T Ichimura, Y Takeda, M Douglas, MMG Kumamoto Inst Technol Dept Appl Microbial Technol Ikeda Kumamoto 8600082 Japan Yamanashi Med Univ Dept Biochem Yamanashi 4093898 Japan Univ N Carolina Sch Med Dept Biochem & Biophys Chapel Hill NC 27599 USA

To better define the regulatory role of the F-1-ATPase Lu-subunit in the catalytic cycle of the ATP synthase complex, we isolated suppressors of mutations occurring in ATP1, the gene for the alpha-subunit in Saccharomyces cerevisiae. First, two atp1 mutations (atp1-1 and atp1-2) mere characterized that prevent the growth of yeast on non-fermentable carbon sources. Both mutants contained full-length F-1 alpha-subunit proteins in mitochondria, but in lower amounts than that in the parental strain. Both mutants exhibited barely measurable F-1- ATPase activity. The primary mutations in atp1-1 and afp1-2 were identified as Thr(383)-->Ile and Gly(291)-->Asp, respectively. From recent structural data, position 383 lies within the catalytic site. Position 291 is located near the region affecting subunit-subunit interaction with the F(1)beta-subunit. An unlinked suppressor gene, ASC1 (alpha-subunit complementing) of the atp1-2 mutation (Gly(291) --> Asp) restored the growth defect phenotype on glycerol, but did not suppress either atp1-1 or the deletion mutant Delta atp1. Sequence analysis revealed that ASC1 was allelic with RAS2, a G-protein growth regulator. The introduction of ASC1/RAS2 into the atp1-2 mutant increased the F-1-ATPase enzyme activity in this mutant when the transformant was grown on glycerol, The possible mechanisms of ASC1/RAS2 suppression of atp1-2 are discussed;we suggest that RAS2 is part of the regulatory circuit involved ill the control of F-1-ATPase subunit levels in mitochondria.

关键词：衔接蛋白质类信号转导氨基酸序列大肠杆菌/酶学真菌蛋白质类/遗传学真菌蛋白质类/代谢 GTP结合蛋白质类甘油/代谢动力学大分子物质线粒体/酶学分子序列数据表型质子转运ATP酶类/化学质子转运ATP酶类/遗传学酿酒酵母菌/遗传学酿酒酵母菌/生长和发育酿酒酵母菌/生理学酿酒酵母蛋白质类裂殖酵母菌属/酶学序列比对序列同源性氨基酸 ras蛋白质类/遗传学 ras蛋白质类/代谢

来源：评论

学校读者我要写书评

暂无评论

Regulatory mechanisms for modulation of signaling through the cell integrity Slt2-mediated pathway in Saccharomyces cerevisiae

引用

JOURNAL OF BIOLOGICAL CHEMISTRY 2000年第2期275卷 1511-1519页

作者： Martín, H Rodríguez-Pachón, JM Ruiz, C Nombela, C Molina, M Univ Complutense Madrid Fac Farm Dept Microbiol 2 E-28040 Madrid Spain

Signal transduction mediated by the mitogen-activated protein kinase (MAPK) Slt2 pathway is essential to maintain the cell wall integrity in Saccharomyces cerevisiae. Stimulation of MAPK pathways results in activation by phosphorylation of conserved threonine and tyrosine residues of MAPKs. We have used an antibody that specifically recognizes dually phosphorylated Slt2 to gain insight into the activation and modulation of signaling through the cell integrity pathway. We show that caffeine and vanadate activate this pathway in the absence of osmotic stabilization. The lack of the putative cell surface sensor Mid2 prevents vanadate- but not caffeine-induced Slt2 phosphorylation. Disruption of the Rhol-GTPase-activating protein genes SAC7 and BEM2 leads to constitutive Slt2 activation, indicating their involvement as negative regulators of the pathway. MAPK kinases also seem to participate in signaling regulation, Mkk1 playing a greater role than Mkk2 in signal transmission to Slt2. Additionally, one of the phosphatases involved in Slt2 dephosphorylation is likely to be the dual specificity phosphatase Msg5, since overexpression of MSG5 in a sac7 Delta mutant eliminates the high Slt2 phosphorylation, and disruption of MSG5 in wild type cells results in increased phosphorylation levels, These data present the first evidence for a negative regulation of the cell integrity pathway.

关键词： DNA结合蛋白质类/代谢真菌蛋白质类/代谢 GTP酶激活蛋白质类基因型 MAP激酶激酶1 MAP激酶激酶2 丝裂原活化蛋白激酶1/代谢丝裂原活化蛋白激酶3 丝裂原激活蛋白激酶激酶类/代谢丝裂原激活蛋白激酶类/代谢磷酰化蛋白质酪氨酸磷酸酶类/代谢蛋白质丝氨酸苏氨酸激酶蛋白酪氨酸激酶类/代谢酿酒酵母菌/遗传学酿酒酵母菌/生长和发育酿酒酵母菌/生理学酿酒酵母蛋白质类信号传导/生理学

来源：评论

学校读者我要写书评

暂无评论

Substitutions of Asn-726 in the active site of yeast DNA topoisomerase I define novel mechanisms of stabilizing the covalent enzyme-DNA intermediate

引用

JOURNAL OF BIOLOGICAL CHEMISTRY 2000年第20期275卷 15246-15253页

作者： Fertala, J Vance, JR Pourquier, P Pommier, Y Bjornsti, MA St Jude Childrens Res Hosp Dept Mol Pharmacol Memphis TN 38105 USA Thomas Jefferson Univ Dept Mol Pharmacol & Biochem Philadelphia PA 19107 USA NCI Mol Pharmacol Lab Div Basic Sci NIH Bethesda MD 20892 USA

Eukaryotic DNA topoisomerase I (Top1p) catalyzes changes in DNA topology and is the cellular target of camptothecin, Recent reports of enzyme structure highlight the importance of conserved amino acids N-terminal to the active site tyrosine and the involvement of Asn-726 in mediating Top1p sensitivity to camptothecin, To investigate the contribution of this residue to enzyme catalysis, we evaluated the effect of substituting His, Asp, or Ser for Asn-726 on yeast Top1p, Top1N726S and Top1N726D mutant proteins were resistant to camptothecin, although the Ser mutant was distinguished by a lack of detectable changes in activity. Thus, a basic residue immediately N-terminal to the active site tyrosine is required for camptothecin cytotoxicity. However, replacing Asn-726 with Asp or His interfered with distinct aspects of the catalytic cycle, resulting in cell lethality. In contrast to camptothecin, which inhibits enzyme-catalyzed religation of DNA, the His substituent enhanced the rate of DNA scission, whereas the Asp mutation diminished the enzyme binding of DNA. Yet, these effects on enzyme catalysis were not mutually exclusive as the His mutant was hypersensitive to camptothecin. These results suggest distinct mechanisms of poisoning DNA topoisomerase I may be explored in the development of antitumor agents capable of targeting different aspects of the Top1p catalytic cycle.

关键词：氨基酸取代天冬酰胺碱基序列结合部位喜树碱/药理学 DNA拓扑异构酶类 Ⅰ型/化学 DNA拓扑异构酶类 Ⅰ型/代谢酶稳定性诱变定点核酸构象质粒/化学质粒/代谢酿酒酵母菌/药物作用酿酒酵母菌/酶学酿酒酵母菌/生长和发育底物特异性

来源：评论

学校读者我要写书评

暂无评论

Yeast communities and genetic polymorphism of Saccharomyces cerevisiae strains associated with artisanal fermentation in Brazil

引用

JOURNAL OF APPLIED MICROBIOLOGY 2000年第1期89卷 24-31页

作者： Pataro, C Guerra, JB Petrillo-Peixoto, ML Mendonça-Hagler, LC Linardi, VR Rosa, CA Univ Fed Minas Gerais Inst Ciencias Biol Dept Microbiol BR-31270901 Belo Horizonte MG Brazil Univ Fed Rio de Janeiro Inst Microbiol BR-21941 Rio De Janeiro Brazil

Yeast communities and genetic polymorphism of prevalent Saccharomyces cerevisiae strains isolated from the spontaneous fermentation of the sugarcane juice during the production of aguardente in three distilleries in the state of Minas Gerais, Brazil, were studied. S. cerevisiae was the prevalent species during the process of aguardente production, but Schizosaccharomyces pombe was predominant in old fermentations in one distillery. Transient yeast species were found in a variable number, probably due to the daily addition of sugarcane juice, and they were different for each of the three distilleries studied. PFGE and PCR analysis of the predominant strains of S. cerevisiae isolated from the fermented must showed a high degree of genetic polymorphism among the three distilleries. A high molecular variability of S . cerevisae strains was also observed among strains isolated from the same vat at different fermentation ages. Our results showed that there was a succession of geneticly different strains of S. cerevisae during the process of aguardente production.

关键词：酒精性饮料巴西发酵禾本科多态现象遗传酿酒酵母菌/遗传学酿酒酵母菌/生长和发育酿酒酵母菌/分离和提纯酵母菌/遗传学酵母菌/生长和发育酵母菌/分离和提纯

来源：评论

学校读者我要写书评

暂无评论

Approaches to detecting false positives in yeast two-hybrid systems

引用

BIOTECHNIQUES 2000年第2期28卷 328-+页

作者： Serebriiskii, I Estojak, J Berman, M Golemis, EA Fox Chase Canc Ctr Philadelphia PA 19111 USA

While many novel associations predicted by two-hybrid library screens reflect actual biological associations of two proteins in vivo, at times the functional co-relevance of two proteins scored as interacting in the two-hybrid system is unlikely The reason for this positive scare remains obscure, which leads to designating such clones as false positives. After investigating the effect of overexpressing a series of putative false positives in yeast, we determined that expression of some of these clones induces an army of biological effects in yeast including altered growth rate and cell permeability, that bias perceived activity of LacZ reporters. Based on these observations, we identify four simple strategies that can assist in determining whether a protein is likely to have been selected in a two-hybrid screen because of indirect metabolic effects.

关键词：生物技术细胞膜通透性假阳性反应乳糖操纵子酿酒酵母菌/遗传学酿酒酵母菌/生长和发育酿酒酵母菌/代谢转录激活双杂交系统技术/统计学和数值数据

来源：评论

学校读者我要写书评

暂无评论

A homolog of voltage-gated Ca²⁺ channels stimulated by depletion of secretory Ca²⁺ in yeast

引用

MOLECULAR AND CELLULAR BIOLOGY 2000年第18期20卷 6686-6694页

作者： Locke, EG Bonilla, M Liang, L Takita, Y Cunningham, KW Johns Hopkins Univ Dept Biol Baltimore MD 21218 USA

In animal cells, capacitative calcium entry (CCE) mechanisms become activated specifically in response to depletion of calcium ions (Ca2+) from secretary organelles. CCE serves to replenish those organelles and to enhance signaling pathways that respond to elevated free Ca2+ concentrations in the cytoplasm. The mechanism of CCE regulation is not understood because few of its essential components have been identified. We show here for the first time that the budding yeast Saccharomyces cerevisiae employs a CCE-like mechanism to refill Ca2+ stores within the secretary pathway, Mutants lacking Pmr1p, a conserved Ca2+ pump in the secretary pathway, exhibit higher rates of Ca2+ influx relative to wild-type cells due to the stimulation of a high-affinity Ca2+ uptake system. Stimulation of this Ca2+ uptake system nas blocked in pmr1 mutants by expression of mammalian SERCA pumps. The high-affinity Ca2+ uptake system was also stimulated in wild-type cells overexpressing vacuolar Ca2+ transporters that competed with Pmr1p for substrate. A screen for yeast mutants specifically defective in the high-affinity Ca2+ uptake system revealed two genes, CCH1 and MID1, previously implicated in Ca2+ influx in response to mating pheromones. Cch1p and Mid1p were localized to the plasma membrane, coimmunoprecipitated from solubilized membranes, and shown to function together within a single pathway that ensures that adequate levels of Ca2+ are supplied to Pmr1p to sustain secretion and growth. Expression of Cch1p and Mid1p was not affected in pmr1 mutants. The evidence supports the hypothesis that yeast maintains a homeostatic mechanism related to CCE in mammalian cells. The homology between Cch1p and the catalytic subunit of voltage-gated Ca2+ channels raises the possibility that in same circumstances CCE in animal cells may involve homologs of Cch1p and a conserved regulatory mechanism.

关键词： ATP结合匣式转运子/遗传学 ATP结合匣式转运子/代谢钙/代谢钙通道/遗传学钙通道/代谢钙转运ATP酶类真菌蛋白质类/代谢离子通道闸门/生理学膜糖蛋白类/代谢分子伴侣诱变酿酒酵母菌/遗传学酿酒酵母菌/生长和发育酿酒酵母菌/代谢酿酒酵母蛋白质类空泡

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：