Endocytic Trafficking in C. elegans and Mammals

线虫和哺乳动物的内吞贩运

• 批准号: 6890872
• 负责人: Barth Demian Grant
• 金额: $ 27.59万
• 依托单位: RUTGERS, THE STATE UNIV OF N.J.
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-05-05 至 2008-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6890872
• 关键词: Caenorhabditis elegans; chemical binding; endocytosis; gene mutation; immunoelectron microscopy; intracellular transport; membrane proteins; nucleotides; protein structure function; protein transport

DESCRIPTION (provided by applicant): Regulated membrane and protein transport is a central component of a multitude of biological processes and is critically important in human heath. For example, transport defects are implicated in hypercholesterolemia, Huntington's disease, and myeloid leukemia. Thus, elaborating molecular mechanisms of membrane trafficking are profoundly important to both basic and applied research. Our interests are in exploiting advantageous features of C. elegans and mammalian cells to investigate one of the least understood steps in endocytic traffic-the return of internalized molecules to the cell surface via recycling endosomes. Surprisingly little is known of the molecules that mediate and regulate this step of recycling. Initial studies indicate this process is highly conserved in metazoans, and may be distinct from related processes in microbes like yeast. Using a genetic approach in C. elegans, we have identified novel proteins that are critical for the recycling process in vivo. One of these, RME-1, is a peripheral membrane protein of the recycling endosome that regulates export from the recycling endosome in a process thought to utilize membrane tubules. RME-1 appears highly conserved between nematodes and mammals in both structure and basic function and is one of the first proteins clearly implicated in this specific recycling step. Mutations in a second protein, GUM-l, cause the same biological defects as mutations in RME-I. Furthermore, GUM-1 is required for the localization of RME-1 to endosomes. The molecular identity of the GUM-1 protein and the mechanism by which it regulates RME-1 localization are currently unknown. We plan to decipher the biology of endocytic recycling by conducting an in-depth multi-pronged analysis of RME-1 and GUM-1 and by applying novel approaches toward the identification of additional proteins that act with RME-1 and GUM-1 in the process of recycling. Our specific aims are: l) To test key working hypotheses that RME-1 is regulated by nucleotide binding and membrane association, and that RME-1 participates in membrane tubule formation. 2) To characterize GUM-l, a novel regulator of endocytic recycling in C. elegans and mammals. 3) To identify additional mediators and regulators of endocytic recycling in C. elegans. By combining the power of C. elegans genetics and mamalian cell biology this work will significantly advance our understanding of .the mechanisms determining a key metazoan membrane transport process.

描述（由申请人提供）：受调节的膜和蛋白质转运是多种生物过程的核心组成部分，在人荒地中至关重要。例如，运输缺陷与高胆固醇血症，亨廷顿氏病和髓样白血病有关。因此，阐述膜运输的分子机制对于基本和应用研究都非常重要。 我们的兴趣是利用秀丽隐杆线虫和哺乳动物细胞的优势特征来研究内吞交通中最不理知识的步骤之一 - 通过回收的内体返回内部化分子到细胞表面。令人惊讶的是，对介导和调节这一回收步骤的分子知之甚少。初步研究表明，该过程在后生动物中是高度保守的，并且可能与酵母等微生物的相关过程不同。使用秀丽隐杆线虫中的遗传方法，我们确定了新型蛋白质，这些蛋白质对于体内回收过程至关重要。其中之一是RME-1，是回收内体的周围膜蛋白，该膜在使用膜小管中调节从回收内体中调节出口。 RME-1在结构和基本功能的线虫和哺乳动物之间似乎是高度保守的，并且是该特定回收步骤中明显涉及的第一个蛋白质之一。第二种蛋白质中的突变，牙龈-L，导致与RME-I突变相同的生物缺陷。此外，将RME-1定位到内体需要GUM-1。目前尚不清楚Gum-1蛋白的分子身份及其调节RME-1定位的机制。 我们计划通过对RME-1和GUM-1进行深入的多沟分析，并通过在回收过程中对其他蛋白质进行RME-1和GUM-1的其他蛋白质进行鉴定，通过对RME-1和GUM-1进行深入的多沟通分析来解密内吞回收的生物学。我们的具体目的是：l）检验关键工作假设，即RME-1受核苷酸结合和膜关联调节，RME-1参与膜小管的形成。 2）要表征Gum-L，这是秀丽隐杆线虫和哺乳动物中内吞回收的新型调节剂。 3）确定秀丽隐杆线虫中内吞回收的其他介体和调节剂。通过结合秀丽隐杆线虫遗传学和Mamalian细胞生物学的能力，这项工作将显着提高我们对确定重要后生膜运输过程的机制。