Neuronal Ykt6 Protein Interactions and Targeting

神经元 Ykt6 蛋白相互作用和靶向

• 批准号: 7000226
• 负责人: JESSE C HAY
• 金额: $ 24.17万
• 依托单位: UNIVERSITY OF MONTANA
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-01-01 至 2007-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7000226
• 关键词: immunoelectron microscopy; intracellular transport; laboratory mouse; laboratory rabbit; laboratory rat; mass spectrometry; membrane proteins; nerve /myelin protein; protein protein interaction; protein transport; yeast two hybrid system

DESCRIPTION (provided by applicant): SNAP receptor (SNARE) proteins catalyze biological membrane fusion and contribute to the fidelity of intracellular membrane traffic - they are perhaps the most fundamental determinant of an organelle's trafficking in the cell. The yeast prenylated SNARE ykt6p appears to have multiple functions in the constitutive secretory pathway. Unexpectedly, our results demonstrate that mammalian ykt6 does not have the characteristics of a SNARE for constitutive secretion, as it is expressed predominantly in neurons. Furthermore, membrane bound rat ykt6 localizes to unique cytoplasmic vesicular structures that do not overlap appreciably with recognized organelles of the secretory or endosomal systems. This proposal aims to dramatically advance our understanding of neuronal ykt6 and the specialized transport process(es) in which it participates. Our guiding hypothesis is that rat ykt6 is involved in the trafficking of a highly specialized transport organelle containing cargo that is important for aspects of neuronal function. The specific aims are: 1. Test the hypothesis that ykt6 interacts with a unique subset of neuronal SNAREs and other membrane and cytosolic proteins. 2. Test the hypothesis that ykt6 is localized to a specialized transport compartment containing cargo relevant to neuronal function. 3. Test the hypothesis that the NT domain targets ykt6 to its specialized location by binding to a specific membrane receptor. 4. Test the hypothesis that cytosolic ykt6 SNARE interactions are autoinhibited by cooperation between the NT domain and prenyl group(s). These studies will dramatically advance our understanding of membrane trafficking in neurons, and highlight underlying processes that may contribute to human disease. Many of the SNARE regulatory principles discovered in this work will be applicable to SNARE function at multiple membrane transport steps. Importantly, ykt6 is a prenyl protein that is predicted to be modified by protein farnesyltransferase. There is currently little information about the function of farnesylated proteins not involved in cell proliferation. Since many of the most promising new cancer treatments use drugs to inhibit protein farnesyltransferase, it is essential to understand the major metabolic pathways affected when protein farnesylation is stopped. To understand and potentially compensate for the unintended consequences of these drugs in neurons, it is essential to understand the function of the ykt6 membrane transport pathway.

描述（由申请人提供）： SNAP 受体 (SNARE) 蛋白催化生物膜融合并有助于细胞内膜运输的保真度 - 它们可能是细胞内细胞器运输的最基本决定因素。酵母异戊二烯化的 SNARE ykt6p 似乎在组成型分泌途径中具有多种功能。出乎意料的是，我们的结果表明哺乳动物 ykt6 不具有 SNARE 的组成型分泌特征，因为它主要在神经元中表达。此外，膜结合的大鼠 ykt6 定位于独特的细胞质囊泡结构，该结构与分泌或内体系统的公认细胞器没有明显重叠。该提案旨在极大地增进我们对神经元 ykt6 及其参与的专门运输过程的理解。我们的指导性假设是，大鼠 ykt6 参与高度专业化的运输细胞器的运输，该细胞器含有对神经元功能很重要的货物。具体目标是： 1. 测试 ykt6 与神经元 SNARE 和其他膜和胞质蛋白的独特子集相互作用的假设。 2. 检验ykt6 定位于含有与神经元功能相关的货物的专门运输隔间的假设。 3. 检验 NT 结构域通过与特定膜受体结合将 ykt6 定位到其专门位置的假设。 4. 检验胞质 ykt6 SNARE 相互作用被 NT 结构域和异戊二烯基团之间的合作自动抑制的假设。这些研究将极大地增进我们对神经元膜运输的理解，并强调可能导致人类疾病的潜在过程。这项工作中发现的许多 SNARE 调控原理将适用于多个膜转运步骤的 SNARE 功能。重要的是，ykt6 是一种异戊二烯基蛋白，预计会被蛋白质法呢基转移酶修饰。目前关于不参与细胞增殖的法尼基化蛋白的功能的信息很少。由于许多最有前途的新癌症治疗方法都使用药物来抑制蛋白质法尼基转移酶，因此了解蛋白质法尼基化停止时受影响的主要代谢途径至关重要。为了了解并潜在地补偿这些药物对神经元的意外后果，有必要了解 ykt6 膜转运途径的功能。