Maltose sensing/signaling mechanisms in Saccharomyces

酵母菌中的麦芽糖传感/信号传导机制

基本信息

批准号：
6760921
负责人：
Corinne Anthony Michels
金额：
$ 30.8万
依托单位：
QUEENS COLLEGE
依托单位国家：
美国
项目类别：
财政年份：
1980
资助国家：
美国
起止时间：
1980-07-01 至 2008-06-30
项目状态：
已结题

项目摘要

The goal of this project is to characterize two maltose sensing/signaling pathways identified in Saccharomyces. The first regulates inducible MAL gene transcription via maltose permease and the MAL-activator. The second stimulates enhanced levels of pseudohyphal differentiation and is distinct from the pathway regulating MAL gene expression. Specific Aim 1 investigates the role of maltose permease in regulating MAL gene expression. Is it a maltose receptor? Methods are described to isolate constitutive mutations in maltose permease and in other proteins that might function as downstream components of the postulated maltose signaling pathway. Additionally, we will test the ability of a heterologous maltose transporter to induce MAL gene expression. Specific Aim 2 investigates the intracellular sorting of maltose permease during synthesis. Included is an analysis of glucose-induced changes in this trafficking pattern and the role of Snfl kinase. Snfl kinase is required posttranscriptionally for maltose permease synthesis. Suppressor analysis and biochemical approaches are described to identify this function. The roles of Stdlp and casein kinase I (Yck1,2p) in the glucose-induced proteolysis of maltose permease will be investigated. Specific Aim 3 explores the role of Hsp90 molecular chaperone in the maltose-induced activation of the MAL- activator. The MAL-activator is an Hsp90 chaperone client protein. We will use our collection of MAL-activator mutants to test a proposed chaperone-mediated model of induction. Mutant MAL-activator turnover, chaperone complex formation, and response to permease overexpression will be assayed. Carbon source regulation of MAL-activator degradation will be examined and the ubiquitin-conjugation pathway components determined, particularly the E3 ubiquitin-protein ligase. Specific Aim 4 will define the upstream components of the maltose sensing/signaling pathway used to stimulate pseudohyphal differentiation, including the maltose receptor. Gpr1 receptor and Gpa2 Galpha protein are not utilized. Tpk2 kinase (PKA) is required but no maltose- stimulated increase in cAMP synthesis is seen. Mutants capable of filamentation on glucose but not maltose will be isolated using transposon-mutagenesis.

该项目的目的是表征糖疗中鉴定出的两个麦芽糖感应/信号传导途径。第一个通过麦芽糖渗透酶和MAL-激活剂调节可诱导的MAL基因转录。第二个刺激了伪氢分化的增强水平，并且与调节MAL基因表达的途径不同。具体目标1研究了麦芽糖渗透酶在调节MAL基因表达中的作用。是麦芽糖受体吗？描述了在麦芽糖渗透酶和其他蛋白质中隔离可能充当假定麦芽糖信号途径下游成分的构成突变的方法。此外，我们将测试异源麦芽糖转运蛋白诱导MAL基因表达的能力。具体目标2研究了合成过程中麦芽糖渗透酶的细胞内分选。其中包括对葡萄糖诱导的这种运输模式变化的分析和SNFL激酶的作用。麦芽糖渗透酶合成后，SNFL激酶是在转录后需要的。描述了抑制剂分析和生化方法以识别此功能。将研究STDLP和酪蛋白激酶I（YCK1,2p）在葡萄糖诱导的麦芽糖渗透酶蛋白水解中的作用。具体目标3探讨了Hsp90分子伴侣在麦芽糖诱导的麦芽活化剂激活中的作用。 MAL-ACRIVATOR是HSP90伴侣客户蛋白。我们将使用我们的MAL激活因子突变体的集合来测试提出的伴侣介导的诱导模型。将分析突变的MAL-激活因子，伴侣复合物的形成以及对渗透酶过表达的反应。将检查碳源降解的碳源调节，并确定泛素偶联途径成分，尤其是E3泛素 - 蛋白蛋白连接酶。特定的目标4将定义用于刺激伪氢分化（包括麦芽糖受体）的麦芽糖传感/信号传导途径的上游成分。 GPR1受体和GPA2 galpha蛋白不使用。需要TPK2激酶（PKA），但没有看到麦芽糖刺激的cAMP合成增加。能够在葡萄糖上进行丝丝但不能麦芽糖的突变体使用转座子 - 苏植物发生分离。