Role of RILP in Autophagy

微管马达蛋白在细胞内具有多种转运功能。这项提案的重点是 哺乳动物自噬中运动蛋白胞浆动力蛋白的新机制。自噬是一个关键问题 负责回收陈旧或受损的蛋白质和细胞器，以及清除有毒蛋白质的细胞功能 集合体。自噬也与神经发育和神经退行性疾病有关。 细胞质动力蛋白是一种主要的运动蛋白，负责广泛的基本细胞作用，包括 逆行轴突运输、细胞分裂、核和细胞迁移。我们现在已经发现，细胞质 动力蛋白调节蛋白RILP(Rab-Interaction Lysosomal Protein)是一种新的神经元和 非神经元自噬。我们发现RILP在一系列阶段中招募dynein到自噬小体中 在整个过程中，通过一系列不同的招聘机制，涉及与 自噬小体蛋白Lc3和ATG5，以及晚期内体/溶酶体蛋白Rab7。我们发现RILP 不仅介导自噬小体的运输，而且在自噬小体的生物发生中也具有令人惊讶的作用。的 更有趣的是，我们发现RILP的表达是由mTOR激酶控制的，它在 细胞对营养缺乏、损伤和有毒蛋白质聚集的反应。我们进一步发现，RILP是 加工p62(/SQSTM1)所必需的，在蛋白质清除中发挥生理作用的直接证据 集合体。因此，RILP似乎代表了理解mTOR如何调节 对各种形式的侮辱或压力作出反应的细胞机械。这项建议是为了制定出详细的 RILP调节和功能的机制，特别是在神经元中。目标1将测试mTOR在 控制RILP的表达，以及PKA在控制RILP/dynein介导的自噬小体运输中的作用。目标2 将确定RILP在自噬小体生物发生和成熟中的作用。目标3将定义一部小说的角色 RILP-dynein-dynactin-Lis1超复合体是我们分离出来的调节自噬小体运输的超复合体。这个 拟议的研究应该为基本的新的自噬途径提供重要的洞察力， 对了解神经退行性疾病和神经发育疾病的病因和控制的启示。

Microtubule motor proteins are responsible for numerous transport functions in cells. This proposal focuses on a novel mechanism for the motor protein cytoplasmic dynein in mammalian autophagy. Autophagy is a critical cellular function responsible for recycling old or damaged proteins and organelles, and for clearing toxic protein aggregates. Autophagy is also implicated in neurodevelopmental and neurodegenerative diseases. Cytoplasmic dynein is a major motor protein responsible for a broad range of basic cellular roles, including retrograde axonal transport, cell division, and nuclear and cell migration. We have now found that the cytoplasmic dynein regulator, RILP (Rab-interacting Lysosomal Protein) acts as a novel master regulator of neuronal and nonneuronal autophagy. We find that RILP recruits dynein to autophagosomes at a succesion of stages throughout this process via a sequence of distinct recruitment mechanisms involving interactions with the autophagosomal proteins LC3 and ATG5, as well as the late endosomal/lysosomal protein Rab7. We find RILP mediates not only autophagosome transport, but has a surprising role in autophagosome biogenesis as well. Of further interest we find RILP expression to be controlled by the mTOR kinase, which plays a central role in the cellular response to nutrient deprivation, injury, and toxic protein aggregation. We find further that RILP is necessary for processing of p62(/SQSTM1), direct evidence for a physiological role in clearance of protein aggregates. RILP appears, therefore, to represent a missing link in understanding how mTOR regulates the cellular machinery in response to diverse forms of insult or stress. This proposal is to work out the detailed mechanisms for RILP regulation and function, especially in neurons. Aim 1 will test the role of mTOR in controlling RILP expression, and of PKA in controlling RILP/dynein-mediated autophagosome transport. Aim 2 Will define the roles of RILP in autophagosome biogenesis and maturation. Aim 3 will define the role of a novel RILP-dynein-dynactin-LIS1 supercomplex we have isolated in regulating autophagosome transport. The proposed studies should provide important insight into a basic new autophagy pathway, with fundamental implications for understanding the etiology and control of neurodegenerative and neurodevelopmental diseases.