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.

说明(由申请人提供)：这是GM50403的通知编号(NOT-OD-09-058)的竞争性修订，通知标题：NIH宣布可为竞争性修订申请提供恢复法案资金。密歇根州受到经济危机的打击尤为严重。此外，去年辉瑞关闭了其位于安娜堡的最大研究园区。这导致2000多名高技能研究人员被解雇，其中许多人仍然失业。这份申请寻求聘用其中三名调查人员，并扩大我们对父母拨款的研究。母公司拨款的总体目标是研究磷脂酰肌醇(3，5)-二磷酸(PI3，5P2)，这是一种丰度很低的相对未被研究的信号脂质。PI3，5P2存在于所有真核生物中，从酵母到人类。我们发现，PI3，5P2的缺失会导致小鼠的围产期死亡和大量的神经变性。此外，在2%的ALS患者中发现了PI3，5P2信号通路的轻微缺陷。父母资助的重点是研究酵母中的PI3，5P2，希望这些研究也能揭示PI3，5P2在人类中的作用。母公司资助的目的是1)确定PI3，5P2在酵母中的水平是如何调节的，以及2)确定PI3，5P2在酵母中的下游效应蛋白。作为Aim 2的一部分，我们发现了270多个PI3，5P2候选结合蛋白。我们目前正在设计最好的方法来确定哪些候选基因是PI3，5P2的真正下游效应者。目前的候选代表了大量与内体相关的事件，包括参与多个膜转运步骤的蛋白，以及液泡ATPase的亚单位，其他转运体和大量的未鉴定蛋白。我们的目标是定义哪些通路需要PI3，5P2来发挥其功能(S)。在这里，我们寻求扩大这些研究，并跟踪一组新的和意想不到的候选人。我们发现，一个主要的细胞调节因子TOR激酶以及TORC1调节因子Kog1/Raptor与PI3，5P2特异而强烈地结合。重要的是，Alan Saltiel博士和他的同事(密歇根大学)有独立的证据表明，哺乳动物猛禽结合了PI3，5P2；并且PI3，5P2是脂肪细胞中Tor1激活所必需的。因此，我们建议扩大我们目前的研究，并实现以下三个目标。1)确定TORC1的新下游靶点，2)确定PI3，5P2是否位于Tor1功能的上游和/或下游，3)确定Tor1和Kog1上与PI3，5P2结合的每个位点，并测试GTR1/GTR2(raga-D)是否直接结合PI3，5P2。 与公共卫生相关：这项申请的总体目标是：1)为有技能的科学家创造就业机会，2)扩大父母资助的目标。我们最近做出了意想不到的发现，TORC1是一种具有关键医学意义的关键细胞调节因子，它与信号脂质PI3，5P2特异而强烈地结合。我们将利用这些发现寻找新的途径来确定TORC1是如何被调控的，并发现新的下游TORC1靶点。