Myoferlin in muscle membrane fusion and repair

肌成纤维蛋白在肌肉膜融合和修复中的作用

• 批准号: 8990655
• 负责人: Elizabeth M McNally
• 金额: $ 31.97万
• 依托单位: NORTHWESTERN UNIVERSITY AT CHICAGO
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-01-01 至 2017-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8990655
• 关键词: Myoferlin; muscle; membrane; fusion; repair

DESCRIPTION (provided by applicant): Mutations in dysferlin cause muscular dystrophy, and the mechanism by which loss of dysferlin leads to muscular dystrophy is a fundamentally different than other forms of muscular dystrophy. Dysferlin is a membrane-associated protein that participates in vesicle trafficking events. In muscle this includes vesicle movement important for plasma membrane repair. Our work has also shown that dysferlin, like other members of the ferlin family, regulates vesicle recycling. We characterized myoferlin and Fer1L5, two highly related proteins to dysferlin to understand whether these proteins have overlapping function to substitute for dysferlin. These ferlin proteins each have at least six C2 domains, domains important for protein-membrane and protein-protein interactions. We identified that the first C2 domain of dysferlin binds negatively charged phospholipids in a calcium sensitive manner. We subsequently showed that ferlin C2 domains bind directly to carboxy-terminal Eps 15 Homology Domain (EHD) proteins, and that EHD proteins are required for ferlin intracellular trafficking. EHD proteins can induce tubule formation in vitro and in cell. We will study the interaction between ferlins, EHD, and Bin1 in the genesis of transverse tubule in muscle. We will then examine the mechanisms by which loss of ferlin proteins renders the muscle susceptible to detubulation and the molecular requirements to restore tubule formation and function. Finally, we will examine recycling events mediated by ferlin proteins. In each step, we will determine the domains of dysferlin, or the related myoferlin and Fer1L5 that mediate these events and assess whether restoration of these functions corrects the underlying pathology in dysferlin-associated muscular dystrophy.

描述（由申请人提供）：Dysferlin的突变引起肌肉营养不良，以及dysferlin导致肌肉营养不良的机制与其他形式的肌肉营养不良根本不同。 Dysferlin是一种与膜相关的蛋白质，参与囊泡运输事件。在肌肉中，这包括对质膜修复重要的囊泡运动。我们的工作还表明，与Ferlin家族的其他成员一样，Dysferlin调节了囊泡回收。我们表征了Myoferlin和FER1L5，这是与Dysferlin的两个高度相关的蛋白质，以了解这些蛋白是否具有重叠功能以替代Dysferlin。这些FERLIN蛋白具有至少六个C2结构域，对于蛋白质包膜和蛋白质 - 蛋白质相互作用很重要。我们确定了Dysferlin的第一个C2结构域以钙敏感的方式结合带负电荷的磷脂。随后，我们表明FERLIN C2结构域直接与羧基末端EPS 15同源域（EHD）蛋白结合，并且EHD蛋白是Ferlin细胞内运输所必需的。 EHD蛋白可以在体外和细胞中诱导小管形成。我们将研究Ferlins，EHD和BIN1在肌肉中横小管的起源中的相互作用。然后，我们将研究Ferlin蛋白损失使肌肉易于肠tub肌的肌肉以及恢复肾小管形成和功能的分子需求的机制。最后，我们将检查由Ferlin蛋白介导的回收事件。在每个步骤中，我们都将确定dysferlin的结构域，或介导这些事件的相关肌曲线和FER1L5，并评估这些功能的恢复是否纠正了与Dysferlin相关的肌肉营养不良中的潜在病理。