Myo1c Participates in Podocyte Junction Formation Through Interaction with Neph1

Myo1c 通过与 Neph1 相互作用参与足细胞连接形成

• 批准号: 8072588
• 负责人: DEEPAK NIHALANI
• 金额: $ 27.21万
• 依托单位: UNIVERSITY OF PENNSYLVANIA
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-05-15 至 2015-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8072588
• 关键词: ATP phosphohydrolase; Actins; Affect; Back; Belief; Binding; Biochemical; Biological Models; Calmodulin; Cell membrane; Cells; Clinical; Complex; Cytoplasm; Cytoskeleton; Data; Development; Diabetes Mellitus; Disease; Dissociation; End stage renal failure; Event; Family; Filtration; Foot Process; Functional disorder; Hypertension; In Vitro; Injury; Intercellular Junctions; Kidney; Knock-in Mouse; Knockout Mice; Lead; Location; Maintenance; Mediating; Membrane; Microscopy; Modeling; Molecular; Molecular Motors; Morbidity - disease rate; Motor; Mus; Mutate; Mutation; Myosin ATPase; Myosin Type I; Organelles; Outcome; Patients; Phosphorylation; Physiological; Play; Prevention; Process; Protein Binding; Protein translocation; Proteins; Proteinuria; Publishing; Recovery; Renal function; Renal glomerular disease; Research; Role; Signal Transduction; Signaling Protein; Site; Small Interfering RNA; Structure; System; Therapeutic; Tight Junctions; United States; base; cell type; glomerular function; improved; in vivo; member; molecular rearrangement; mortality; mouse model; mutant; nephrin; novel; podocyte; prevent; protein complex; public health relevance; response; restoration; slit diaphragm; tool

DESCRIPTION (provided by applicant): Glomerular diseases that lead to damaging changes in kidney filtration are an increasing cause of ESRD (end stage renal disease) nationwide. Unfortunately, the molecular mechanisms governing the development of ESRD remain poorly understood. Identification of podocyte proteins, including Neph1 and its associated protein complex, that are critical components of kidney filtration was a major advancement in understanding the organization of slit diaphragm. A number of recent studies, including ours, now demonstrate that dynamic interactions between Neph1 and its associated proteins including Grb2, ZO-1, Nephrin and Par3 regulates the actin cytoskeleton at the slit diaphragm. Data also suggest that Neph1 and its complex are frequently found in various sub cellular compartments away from the cell membrane following glomerular injury. Retargeting these proteins back to their membrane filtration slit location is likely to require an active molecular motor-based mechanism. We now have exciting results that identify a novel interaction of Neph1 with Myo1c, a member of the un-conventional Myosin family whose members are ATPase motor proteins that bind to actin and can generate force. Myo1c also has membrane binding and Calmodulin binding domains and has been shown to have a role in membrane cytoskeletal events in diverse cell types. We recently published an article demonstrating that glomerular injury results in mis-localization of the Neph1 complex leading to loss of cell junctions and proteinuria, whereas recovery from injury correlates with the Neph1 complex's return to the cell periphery (Wagner et al., JBC 2008). We believe that the interaction of Neph1 with Myo1c plays a critical role in regulating the organization of the Neph1 complex. In this study we propose to investigate the Neph1 and Myo1c interaction under in-vitro and in- vivo conditions. The specific aims proposed for this study are: 1) Define the physiologic and pathophysiologic organization of Myo1c in podocytes. 2) Determine the significance of Myo1c-Neph1 interaction in the assembly and translocation of Neph1 complex to the filtration slit in response to glomerular injury. 3) Determine the significance of Myo1c and its interaction with Neph1 in maintaining the glomerular function under in-vivo conditions. The results from this study will increase our understanding of how slit diaphragm proteins organize under both physiological and nonphysiological conditions resulting in new avenues of research aimed at improving clinical outcome following glomerular injury. PUBLIC HEALTH RELEVANCE: Glomerular diseases leading to end stage renal disease are major cause of kidney malfunction in United States. Our previous studies have shown that functional and biochemical changes in the proteins that are central to the maintenance of the kidney filtration system leads to the development of glomerular disorders. In this study we will determine the role of a novel protein Myo1c and identify novel targets for use in the development of novel therapies aimed at restoring the selective filtration function of kidneys during various glomerular disorders.

描述（由申请人提供）：导致肾脏过滤破坏性变化的肾小球疾病是全国范围内 ESRD（终末期肾病）的一个日益增加的原因。不幸的是，人们对 ESRD 发展的分子机制仍知之甚少。足细胞蛋白（包括 Neph1 及其相关蛋白复合物）的鉴定是肾脏滤过的关键组成部分，是了解裂隙隔膜组织的重大进展。最近的许多研究，包括我们的研究，现在证明 Neph1 及其相关蛋白（包括 Grb2、ZO-1、Nephrin 和 Par3）之间的动态相互作用调节裂隙隔膜处的肌动蛋白细胞骨架。数据还表明，肾小球损伤后，Neph1 及其复合物经常出现在远离细胞膜的各种亚细胞区室中。将这些蛋白质重新定位回其膜过滤狭缝位置可能需要基于主动分子马达的机制。我们现在获得了令人兴奋的结果，确定了 Neph1 与 Myo1c 的新型相互作用，Myo1c 是非常规肌球蛋白家族的成员，其成员是 ATP 酶运动蛋白，可与肌动蛋白结合并产生力。 Myo1c 还具有膜结合域和钙调蛋白结合域，并且已被证明在不同细胞类型的膜细胞骨架事件中发挥作用。我们最近发表了一篇文章，证明肾小球损伤导致 Neph1 复合物定位错误，从而导致细胞连接丢失和蛋白尿，而损伤的恢复与 Neph1 复合物返回细胞外周相关（Wagner 等人，JBC 2008）。我们认为 Neph1 与 Myo1c 的相互作用在调节 Neph1 复合体的组织中起着至关重要的作用。在这项研究中，我们建议研究 Neph1 和 Myo1c 在体外和体内条件下的相互作用。本研究提出的具体目标是：1) 定义足细胞中 Myo1c 的生理和病理生理组织。 2)确定Myo1c-Neph1相互作用在Neph1复合物组装和易位至滤过缝以响应肾小球损伤中的重要性。 3)确定Myo1c及其与Neph1相互作用在体内条件下维持肾小球功能的重要性。这项研究的结果将加深我们对狭缝隔膜蛋白在生理和非生理条件下如何组织的理解，从而为旨在改善肾小球损伤后临床结果的研究提供新途径。 公共卫生相关性：导致终末期肾病的肾小球疾病是美国肾功能障碍的主要原因。我们之前的研究表明，对于维持肾脏过滤系统至关重要的蛋白质的功能和生化变化会导致肾小球疾病的发生。在这项研究中，我们将确定一种新型蛋白质 Myo1c 的作用，并确定用于开发新疗法的新靶点，旨在恢复各种肾小球疾病期间肾脏的选择性滤过功能。