Inositol lipid regulation of membrane fusion and fission

肌醇脂质对膜融合和裂变的调节

• 批准号: 7810115
• 负责人: Lois S Weisman
• 金额: $ 28.85万
• 依托单位: UNIVERSITY OF MICHIGAN AT ANN ARBOR
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-01-28 至 2010-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7810115
• 关键词: Adipocytes; Affinity; Binding; Binding Proteins; Cells; Collaborations; Complex; Data; Defect; Economics; Employment Opportunities; Eukaryota; Event; Follow-Up Studies; Funding; Goals; Human; In Vitro; Inositol; Lipids; Lysosomes; Maps; Medical; Membrane Fusion; Membrane Protein Traffic; Metabolism; Michigan; Minor; Modeling; Monomeric GTP-Binding Proteins; Mus; Nerve Degeneration; Neurologic; Pathway interactions; Patients; Perinatal; Phosphatidylinositols; Phosphorylation; Phosphorylation Site; Phosphotransferases; Proteins; Raptors; Recombinant Proteins; Recovery; Recruitment Activity; Regulation; Research; Research Personnel; Scientist; Signal Pathway; Signal Transduction; Site; Stream; Testing; Unemployment; United States National Institutes of Health; Vacuole; Yeasts; follow-up; insight; mutant; novel; parent grant; public health relevance; vacuolar H+-ATPase

DESCRIPTION (provided by applicant): This is a Competitive Revision for GM50403 of Notice Number (NOT-OD-09-058), and Notice Title: NIH Announces the Availability of Recovery Act Funds for Competitive Revision Applications. The state of Michigan has been particularly hard hit by the economic crisis. Moreover, last year Pfizer closed its largest research campus; located here in Ann Arbor. This resulted in the termination of over 2000 highly skilled researchers, many of whom remain unemployed. This application seeks to employ three of these investigators, and also to expand our studies of the parent grant. The overall goal of the parent grant is to study phosphatidylinositol (3,5)-bisphosphate (PI3,5P2), a very low abundance, and relatively unstudied signaling lipid. PI3,5P2 is found in all eukaryotes, from yeast to humans. We found that depletion of PI3,5P2 leads to perinatal lethality and massive neurodegeneration in mice. Moreover, minor defects in the PI3,5P2 signaling pathway are found in 2% of ALS patients. The focus of the parent grant is to study PI3,5P2 in yeast, in the hopes that these studies will reveal insights into PI3,5P2 function in humans as well. The Aims of the parent grant are 1) determine how levels of PI3,5P2 are regulated in yeast, and 2) determine proteins that are downstream effectors of PI3,5P2 in yeast. As part of Aim 2, we uncovered over 270 PI3,5P2 candidate binding proteins. We are currently devising the best approaches to determine which candidates are bona fide downstream effectors of PI3,5P2. The current candidates represent a large number of endosomal related events including proteins involved in multiple membrane trafficking steps, and also subunits of the vacuolar ATPase, other transporters and a significant number of uncharacterized proteins. Our goal is to define which pathways require PI3,5P2 for their function(s). Here we seek to expand these studies and follow up on a set of new and unexpected candidates. We found that a major cell regulator, the TOR kinase, as well as the TORC1 regulator, Kog1/Raptor, bind specifically and avidly to PI3,5P2. Importantly, Dr. Alan Saltiel and co-workers (U. Michigan) have independent evidence that mammalian Raptor binds PI3,5P2; and that PI3,5P2 is required for the activation of Tor1 in adipocytes. Thus, we propose to expand our current studies and to perform the following three aims. 1) Identify novel downstream targets of TORC1, 2) Determine whether PI3,5P2 is upstream and/or downstream of Tor1 function, and 3) Determine each site on Tor1 and Kog1 that bind PI3,5P2, and also test whether Gtr1/Gtr2 (RagA-D) directly bind PI3,5P2. PUBLIC HEALTH RELEVANCE: The overall goals of this application, are to 1) create employment opportunities for skilled scientists, and 2) expand the goals of the parent grant. We recently made the unexpected finding that TORC1, a key cellular regulator of critical medical importance, binds specifically and avidly to the signaling lipid PI3,5P2. We will exploit these findings to pursue new avenues to determine how TORC1 is regulated, and to uncover novel downstream TORC1 targets.

描述（由申请人提供）：这是通知号的GM50403（非OD-09-058）的竞争性修订版，并通知标题：NIH宣布可用于竞争性修订申请的恢复法案资金。密歇根州受到经济危机的打击尤其严重。此外，去年辉瑞公司关闭了其最大的研究校园。位于安阿伯。这导致终止了2000多名高技能研究人员，其中许多人仍然失业。该申请旨在雇用其中三名调查人员，并扩大我们对父母赠款的研究。父授予的总体目标是研究磷脂酰肌醇（3,5）二磷酸（PI3,5P2），丰度非常低，相对未研究的信号脂质。从酵母到人类的所有真核生物中都发现了PI3,5p2。我们发现PI3,5P2的耗竭会导致小鼠围产期致死性和大量神经变性。此外，在2％的ALS患者中发现了PI3,5P2信号通路中的较小缺陷。父母赠款的重点是研究酵母中的PI3,5P2，希望这些研究也能揭示对人类中PI3,5P2功能的见解。父授予的目的是1）确定酵母中PI3,5P2的水平如何调节，2）确定蛋白质是PI3,5P2在酵母中的下游效应子。作为AIM 2的一部分，我们发现了超过270个PI3,5P2候选蛋白。我们目前正在设计最佳方法，以确定哪些候选者是PI3,5P2的真正下游效应子。当前的候选者代表了许多相关的内体相关事件，包括参与多个膜运输步骤的蛋白质，以及液泡ATPase，其他转运蛋白和大量未表征的蛋白质的亚基。我们的目标是定义哪种途径需要PI3,5P2才能进行功能。在这里，我们试图扩大这些研究并跟进一系列新的和意外的候选人。我们发现，主要细胞激酶以及Torc1调节剂KOG1/RAPTOR特异性且狂热地结合了PI3,5P2。重要的是，艾伦·萨尔蒂尔（Alan Saltiel）博士和同事（美国密歇根州）有独立的证据，表明哺乳动物猛禽结合PI3,5P2；脂肪细胞中TOR1的激活需要PI3,5P2。因此，我们建议扩大我们当前的研究并执行以下三个目标。 1）确定TORC1的新型下游靶标，2）确定PI3,5P2是否在TOR1功能的上游和/或下游，以及3）确定结合PI3,5p2的TOR1和KOG1上的每个位点，还测试GTR1/GTR2（RAGA-D）是否直接粘合PI3,5,5p2。 公共卫生相关性：本应用程序的总体目标是1）为熟练的科学家创造就业机会，以及2）扩大父母赠款的目标。最近，我们提出了一个意外的发现，TORC1是关键医学重要性的关键细胞调节剂，它专门且与信号脂质PI3,5P2专门结合。我们将利用这些发现来追求新的途径，以确定TORC1的调节方式，并发现新颖的下游TORC1目标。