Regulation of Myosin V Interaction with Cargo

肌球蛋白 V 与货物相互作用的调节

• 批准号: 7932391
• 负责人: Lois S Weisman
• 金额: $ 8.88万
• 依托单位: UNIVERSITY OF MICHIGAN AT ANN ARBOR
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-09-30 至 2010-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7932391
• 关键词: Actins; Adaptor Signaling Protein; Affect; Animals; Behavior; Binding; Binding Sites; Cell division; Cell physiology; Complex; Cytomegalovirus Infections; Defect; Deposition; Destinations; Diarrhea; Dimerization; Disease; Dominant-Negative Mutation; Employee Strikes; Eukaryota; Fluorescence; Genes; Goals; Golgi Apparatus; Hallmark Cell; Human; In Vitro; Individual; Intracellular Transport; Lead; Life; Link; Location; MLPH gene; MYO5A gene; Measures; Melanosomes; Microtubules; Morphology; Motor; Movement; Mutation; Myosin ATPase; Myosin Type V; Neurologic; Organelles; Peptides; Pharmaceutical Preparations; Phosphorylation Site; Phosphotransferases; Physiology; Pigmentation physiologic function; Play; Point Mutation; Positioning Attribute; Protein Binding; Proteins; Regulation; Resolution; Role; Saccharomyces cerevisiae; Secretory Vesicles; Sirolimus; Site; Specific qualifier value; Structure; Surface; Syndrome; Tacrolimus Binding Proteins; Tail; Testing; Time; To specify; Vacuole; Vesicle; Yeasts; base; cell type; cellular microvillus; design; dimer; human disease; in vivo; infancy; insight; monomer; mutant; nervous system disorder; novel; organelle movement; public health relevance; rab GTP-Binding Proteins; small molecule

DESCRIPTION (provided by applicant): Organelle movement is a hallmark of cell division and cellular differentiation. In every cell-type, the localization, number and morphology of each type of organelle is modified to achieve specific cellular functions. Long-range movement of organelles occurs on microtubules, while positioning of organelles at their final destination relies on actin-based motors. Myosin V motors play a critical role in actin based movement in all eukaryotes, and disruption of myosin V function causes disease in humans. For example, partial defects in myosin Va based transport cause Griscelli's syndrome, characterized by neurological and pigmentation defects. Partial defects in myosin Vb cause microvillus inclusion disease, characterized by infantile, life threatening diarrhea. Currently there are no effective drug-based treatments for either disease. Determination of how myosin V based transport is achieved may provide important new insights into treating theseetach from cargoes at the correct time and place. The globular tail domain (GTD) of myosin V attaches to its cargoes through organelle-specific adaptor proteins. Regulation of the GTD and adaptor proteins contributes to specifying cargo attachment. We determined a high-resolution structure of the GTD of Myo2, a Saccharomyces cerevisiae myosin V motor, and identified two distinct cargo binding regions; one required for binding to the yeast vacuole, the other required for binding to secretory vesicles. We found that the vacuole binding site interacts with a novel protein, Vac17. The secretory vesicle binding site attaches directly to a Rab GTPase. Importantly, we found that the Rab GTPase binding site is conserved in human myosin Va and myosin Vb. Thus, our studies in yeast revealed the Rab GTPase binding site on human myosin V motors. The general conservation of the cargo binding domains of yeast Myo2 and human myosin Va and Vb, and the fact that Rab GTPases act directly to attach carns. Our major goals are to: 1) Determine whether the binding of an individual Myo2 adaptor protein enhances or inhibits binding of other adaptor proteins. 2) Identify and characterize proteins that regulate the attachment of Rab GTPases to the GTD of Myo2. 3) Determine mechanisms that regulate the detachment of myosin V from cargoes. PUBLIC HEALTH RELEVANCE: Intracellular transport of organelles by myosin V motors is crucial to normal cellular function, and animal physiology. Defects in myosin V based transport cause selected human diseases including neurological disorders. Our overall goal is to determine the mechanisms that regulate for myosin V-based transport.

描述（由申请人提供）：细胞器运动是细胞分裂和细胞分化的标志。在每一种细胞类型中，每种细胞器的定位、数量和形态都被改变以实现特定的细胞功能。细胞器的远距离运动发生在微管上，而细胞器在最终目的地的定位依赖于基于肌动蛋白的马达。肌凝蛋白V马达在所有真核生物中以肌动蛋白为基础的运动中起关键作用，肌凝蛋白V功能的破坏会导致人类疾病。例如，肌球蛋白Va转运的部分缺陷导致Griscelli综合征，其特征是神经和色素沉着缺陷。肌球蛋白Vb的部分缺陷引起微绒毛包涵性疾病，以婴儿危及生命的腹泻为特征。目前，这两种疾病都没有有效的药物治疗方法。确定基于肌凝蛋白V的转运是如何实现的，可能为在正确的时间和地点处理来自货物的这些物质提供重要的新见解。肌球蛋白V的球状尾结构域（GTD）通过细胞器特异性接头蛋白附着在其货物上。GTD和接头蛋白的调节有助于指定货物附着。我们确定了Myo2的GTD的高分辨率结构，Myo2是一种酿酒酵母的肌球蛋白V马达，并确定了两个不同的货物结合区；一个需要与酵母液泡结合，另一个需要与分泌囊结合。我们发现液泡结合位点与一种新的蛋白Vac17相互作用。分泌囊泡结合位点直接附着在rabb GTPase上。重要的是，我们发现Rab GTPase结合位点在人肌凝蛋白Va和肌凝蛋白Vb中是保守的。因此，我们在酵母中的研究揭示了Rab GTPase在人肌凝蛋白V马达上的结合位点。酵母Myo2和人肌球蛋白Va和Vb的货物结合域的普遍保守性，以及Rab gtpase直接作用于附着小车的事实。我们的主要目标是：1)确定单个Myo2接头蛋白的结合是否增强或抑制其他接头蛋白的结合。2)鉴定和表征调节Rab GTPases附着于Myo2 GTD的蛋白。3)确定调节肌球蛋白V脱离货物的机制。