Filopodia in Leukocyte and Endothelial Cell Function

白细胞和内皮细胞功能中的丝状伪足

• 批准号: 7217764
• 负责人: RICHARD E CHENEY
• 金额: $ 25.01万
• 依托单位: UNIV OF NORTH CAROLINA CHAPEL HILL
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-07-01 至 2011-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7217764
• 关键词: SDS polyacrylamide gel electrophoresis; biological signal transduction; cell adhesion; cell component structure /function; cell components; chemotaxis; immune response; immunofluorescence technique; inflammation; integrins; leukocytes; matrix assisted laser desorption ionization; myosins; phagocytosis; protein binding; protein localization; protein protein interaction; protein structure function; receptor expression; tissue /cell culture; vascular endothelium; SDS polyacrylamide gel electrophoresis; biological signal transduction; cell adhesion; cell component structure /function; cell components; chemotaxis; immune response; immunofluorescence technique; inflammation; integrins; leukocytes; matrix assisted laser desorption ionization; myosins; phagocytosis; protein binding; protein localization; protein protein interaction; protein structure function; receptor expression; tissue /cell culture; vascular endothelium

Growing evidence indicates that the slender actin-based extensions known as filopodia play central roles in the cell biology underlying inflammation and angiogenesis. The initial contacts between leukocytes and endothelial cells during leukocyte rolling occur at the tips of filopodia-like structures and endothelial "pathfinder" cells appear to be guided by filopodia during angiogenesis. Despite these critical roles of filopodia in leukocytes and endothelial cells, the molecular mechanisms underlying filopodial extension, adhesion, and signaling are largely unknown. Our discovery that myosin-X (Myo10) is a core component of a putative filopodial tip complex, is involved in filopodia formation, and undergoes a novel form of motility in filopodia, gives us a powerful tool to investigate these questions. We therefore propose to: I. Determine the functional consequences of MyolO's interaction with integrins. Since Myo10 is an unconventional myosin whose tail includes a PERM domain that can binds to the cytoplasmic domains of pintegrins, we will test whether binding to this motor protein activates integrins. We will also test if Myo10 binds to the leukocyte specific beta2-integrins and if Myo10 is required for complement-mediated phagocytosis. II. Analyze the functions of Myo10 in leukocytes and endothelial cells in processes such as filopodial extension, chemotaxis, and transendothelial migration using siRNA and a dominant negative construct. Although Myo10 is the MyTH-FERM myosin expressed in most vertebrate cells and a related myosin in lower organisms is required for filopodia formation, adhesion, and phagocytosis, almost nothing is known about the functions of this family of myosins in leukocytes and endothelial cells. III. Define the basic biochemical properties and components of the filopodial tip complex. Like the focal adhesion, the filopodial tip complex appears to function as a specialized site of cell adhesion, signaling, and actin polymerization, but currently very little is known about the molecular components and properties of the filopodial tip complex. This work is of great relevance to public health because it will investigate the fundamental cell biological mechanisms of inflammation and cell signaling that underlie cardiovascular disease and other serious human health problems.

越来越多的证据表明，基于肌动蛋白的细长扩展名被称为丝状虫在 炎症和血管生成的基础细胞生物学。白细胞和 白细胞滚动过程中的内皮细胞发生在类似丝状的结构和内皮的尖端 在血管生成过程中，“探路者”细胞似乎是由丝状虫引导的。尽管有这些关键角色 白细胞和内皮细胞中的丝状菌素，丝状延伸的分子机制， 粘附和信号传导在很大程度上未知。我们发现肌球蛋白-X（myo10）是 推定的丝虫尖端复合物，参与丝状形成，并在 Filopodia为我们提供了一个强大的研究来调查这些问题。因此，我们建议： I.确定Myolo与整合素的相互作用的功能后果。因为myo10是一个 非常规的肌球蛋白的尾部包括一个可以结合到二豆多素的细胞质结构域的perm结构域， 我们将测试与该运动蛋白的结合是否激活整联蛋白。我们还将测试Myo10是否 与白细胞特异性β2-紧密蛋白结合，如果需要肌息肉的吞噬作用。 ii。分析Myo10在白细胞和内皮细胞中的功能 使用siRNA和显性阴性的丝状扩展，趋化性和跨内皮迁移 构造。尽管Myo10是在大多数脊椎动物细胞中表达的神话肌球蛋白，并且 丝状形成，粘附和吞噬作用是较低生物体中的肌球蛋白，几乎没有什么是 知道该肌动物家族在白细胞和内皮细胞中的功能。 iii。定义丝状尖端复合物的基本生化特性和成分。喜欢 局灶性粘附，丝状尖端复合物似乎是细胞粘附，信号传导的专业部位 和肌动蛋白聚合，但目前对分子成分和特性知之甚少 丝状尖端复合物。 这项工作与公共卫生非常相关，因为它将调查基本细胞生物学 炎症和细胞信号的机制是心血管疾病和其他严重性的基础 人类健康问题。