Myosin Functions in the Enterocyte

肌球蛋白在肠上皮细胞中的功能

• 批准号: 7587362
• 负责人: MARK S MOOSEKER
• 金额: $ 33.22万
• 依托单位: YALE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1979
• 资助国家: 美国
• 起止时间: 1979-04-01 至 2011-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7587362
• 关键词: Actin-Binding Protein; Actins; Address; Apical; Biological Models; Brush Border; Cell Line; Cell physiology; Clathrin; Complex; Coupling; Cytoskeletal Modeling; Cytoskeleton; Defect; Dominant-Negative Mutation; Endocytosis; Enterocytes; Epithelial Cells; Family; In Vitro; Inflammatory Bowel Diseases; Inherited; Injury; Intestinal Mucosa; Intestines; Link; Maintenance; Malabsorption Syndromes; Membrane; Membrane Microdomains; Membrane Protein Traffic; Microfilaments; Molecular; Molecular Motors; Mus; Mutant Strains Mice; Mutate; Myosin ATPase; Nonmuscle Myosin Type IIA; Nonmuscle Myosin Type IIB; Pathway interactions; Permeability; Physiological; Play; Regulation; Role; Tail; Testing; Wound Healing; base; basolateral membrane; brush border membrane; human disease; in vivo; insight; intestinal epithelium; member; myosin VI; response

DESCRIPTION (provided by applicant): The actin-based cytoskeleton of the intestinal epithelial cell (enterocyte) plays critical roles in the absorptive and barrier functions of the intestinal mucosa. The apical brush border (BB) domain of the enterocyte is a complex, highly ordered array of actin filaments and associated actin-binding proteins including numerous members of the myosin family of actin-based molecular motors, a number of which are mutated in inherited human diseases. The proposed studies will test a number of inter-related hypotheses regarding the functions for myosins in the enterocyte. Because the enterocyte represents one of the best model systems for investigating the actin cytoskeleton, these studies will provide insights of both specific and general significance. The initial focus will be on myosin-la (Myola) and two other myosins with which it has functional synergy, myosin-VI (Myo6) and myosin-le (Myole). Myola forms links between the microvillar (MV) membrane and underlying actin core. Myo6 is associated with the clathrin-rich interMV domain, while Myole is found on both apical and basolateral membranes. Assessment of function is facilitated by availability of mutant mouse lines for these 3 myosins. There are marked compositional and structural defects in the BB membrane and underlying cytoskeleton in enterocytes of mice lacking Myola including the loss of Myo6 and Myole. Hypotheses will be tested to examine the role of these myosins in a number of critical cellular processes. These include the maintenance BB membrane composition and structural integrity, regulation of BB actin assembly dynamic and endocytosis. Hypotheses investigating the role of these myosins in the barrier functions of the enterocyte will address the role of these myosins in the regulation of the paracellular barrier and response to mucosal injury. In addition to in in vivo and in vitro studies using the mutant mouse lines, parallel studies will be performed using an intestinal epithelial cell line in which Myola, Myole or Myo6 functions in regulating actin assembly, endocytosis, and wound healing have been disrupted through expression of GFP-tagged, dominant negative-tails of these myosins. These studies should provide critical insights into the role of myosins in enterocyte function-information essential to understand human diseases of the intestine including inflammatory bowel disease and malabsorption syndromes. Moreover, many myosins are targets for human diseases, including 2 of the 3 to be investigated.

描述（由申请人提供）：肠上皮细胞（肠上皮细胞）的基于肌动蛋白的细胞骨架在肠粘膜的吸收和屏障功能中起关键作用。肠上皮细胞的顶刷边界（BB）结构域是一个复杂的，高度有序的肌动蛋白丝和相关的肌动蛋白结合蛋白，其中包括基于肌动蛋白的肌动蛋白家族的众多成员，其中许多是在遗传性人类疾病中突变的。拟议的研究将检验有关肠球细胞中肌球蛋白功能的许多相互关联的假设。由于肠上皮细胞是研究肌动蛋白细胞骨架的最佳模型系统之一，因此这些研究将提供有关特定和一般意义的见解。最初的重点将放在肌球蛋白LA（肌球蛋白）和其他两个具有功能性协同作用的肌球蛋白上，肌球蛋白VI（Myo6）和肌球蛋白-LE（肌肉）。 Myola在微绒毛（MV）膜和基础肌动蛋白核之间形成联系。 Myo6与富含网状蛋白的InterMV结构域相关，而在顶端和基底外侧膜上都发现了迈尔。通过这3种肌动物的突变小鼠系可用性，功能的评估促进了。 BB膜中存在明显的组成和结构缺陷，以及缺乏肌性小鼠的肠肠细胞中的基础细胞骨架，包括肌肉损失，包括Myo6和Myole。将测试假设以检查这些肌动物在许多关键细胞过程中的作用。其中包括维护BB膜组成和结构完整性，BB肌动蛋白组装动态和内吞作用的调节。假设研究这些肌动物在肠上皮细胞的屏障功能中的作用将解决这些肌动物在调节细胞细胞屏障和对粘膜损伤的反应中的作用。除了使用突变小鼠系的体内和体外研究外，还将使用肠上皮细胞系进行平行研究，其中肌动蛋白，内吞作用和伤口愈合在调节肌动蛋白组装，内吞作用和伤口愈合方面的作用通过GFP指定的，tagepppppppppppppppp的负面负面阴性，这些肌蛋白的主导地位。这些研究应提供有关肌醇在了解肠道疾病（包括炎症性肠病和吸收不良综合征）中的人类疾病至关重要的肠球菌功能信息中的作用的关键见解。此外，许多肌动物是人类疾病的靶标，包括要研究的3个肌肉蛋白。