Regulation of Phospholipase C-beta Isozymes

磷脂酶 C-β 同工酶的调节

• 批准号: 6938778
• 负责人: STEPHANIE N HICKS
• 金额: $ 4.21万
• 依托单位: UNIV OF NORTH CAROLINA CHAPEL HILL
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-07-01 至 2008-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6938778
• 关键词: G protein; X ray crystallography; biological signal transduction; enzyme activity; enzyme mechanism; guanine nucleotide binding protein; guanosinetriphosphatases; isozymes; phospholipase C; postdoctoral investigator; protein engineering; protein protein interaction; protein structure function

DESCRIPTION (provided by applicant): PLC-beta isozymes are stimulated by direct interaction with activated heterotrimeric G proteins as well as Rac isozymes of the Rho family of GTPases. Active PLC-beta isozymes catalyze the hydrolysis of phosphoinositides leading to the release of calcium stores and stimulation of protein kinase C, which are required for a variety of normal cellular processes. Conversely, abnormal signaling through PLC-beta leads to a variety of diseases including acute myeloid leukemia, cardiac hypertrophy and hypertension, and ataxia. The focus of this proposal is to determine mechanisms of regulation of phospholipase C-beta (PLC-beta) by Rho GTPases and heterotrimeric G proteins. In the first aim, crystal structures of isolated PLC- beta2 as well as PLC-beta2 bound to Gbetagamma will be determined and compared with the existing structure of PLC-beta2 bound to Rac to define modes of PLC-beta activation at atomic resolution. In the second aim, these structural analyses will be combined with existing data to generate mutant proteins to manipulate PLC-beta activation in vitro and in vivo. Cumulatively, these proposed studies are designed to provide a coherent framework for understanding and manipulating PLC-beta activation by various modulators for the ultimate goal of treating attendant diseases.

描述（由申请人提供）： PLC-β同工酶通过与活化的异三聚体G蛋白以及RHO GTPase家族的RAC同工酶直接相互作用而受到刺激。 活性PLC-β同工酶催化磷酸肌醇的水解导致钙储存的释放并刺激蛋白激酶C，这是多种正常细胞过程所必需的。 相反，通过PLC-β的异常信号传导导致多种疾病，包括急性髓样白血病，心脏肥大和高血压以及共济失调。 该建议的重点是确定Rho GTPases和异三聚体G蛋白调节磷脂酶C-beta（PLC-BETA）的机制。 在第一个目标中，将确定与Gbetagamma结合的分离plc-Beta2以及与Gbetagamma结合的PLC-BETA2的晶体结构，并与与RAC结合的PLC-Beta2的现有结构进行比较，以定义原子分辨率下的PLC-Beta激活模式。 在第二个目标中，这些结构分析将与现有数据结合使用，以生成突变蛋白，以在体外和体内操纵PLC-β激活。 累积地，这些拟议的研究旨在提供一个连贯的框架，以理解和操纵各种调节剂的PLC-beta激活，以便治疗随之而来的疾病。