Tyr-phosphorylation of PKC-delta and myocyte function

PKC-δ 的酪氨酸磷酸化和肌细胞功能

• 批准号: 7158009
• 负责人: AARON C HINKEN
• 金额: $ 4.6万
• 依托单位: UNIVERSITY OF ILLINOIS AT CHICAGO
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-08-16 至 2008-08-15
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7158009
• 关键词: SDS polyacrylamide gel electrophoresis; biological signal transduction; cardiac myocytes; densitometry; enzyme activity; genetic regulation; laboratory mouse; laboratory rat; phosphorylation; postdoctoral investigator; protein kinase C; protein localization; western blottings

DESCRIPTION (provided by applicant): The general objective of this proposal is to define the role of tyrosine residue phosphorylation in the regulation of protein kinase C delta (PKCd) in myocardial tissue. The hypothesis to be tested is that agonist-specific activation of PKCd involves tyrosine phosphorylation which modifies PKC myofilament substrate specificity and kinase activity. Experiments will characterize tyrosine phosphorylation status on PKCd with various stimuli and the impact on myocyte mechanical function. In addition, the effect of tyrosine residue replacement with unphosphorylatable or pseudo-phosphorylated amino acids in the hinge, pseudosubstrate, and activation loop domains on PKCd localization and substrate specificity will be determined. Finally, experiments will resolve whether PKCd activation promotes the activity of other signal transduction pathways involved in regulation pathophysiological processes (hypertrophy or apoptosis. Compelling preliminary evidence indicates phosphorylation of specific tyrosine residues of PKCd alters substrate specificity particularly in respect to troponin (Tn) complex components. In addition, phosphorylated tyrosine (pY) may change the cofactor requirements of the kinase enabling lipid independent activity. Results will provide novel information regarding stimuli specific PKCd activation and activity as well as the effect on cardiac myofilament phosphorylation and myocyte functional capabilities.

描述（由申请人提供）：该提案的总体目标是确定酪氨酸残基磷酸化在心肌组织中蛋白激酶C δ（PKCd）调节中的作用。要测试的假设是 PKCd 的激动剂特异性激活涉及酪氨酸磷酸化，这会改变 PKC 肌丝底物特异性和激酶活性。实验将表征各种刺激下 PKCd 酪氨酸磷酸化状态及其对心肌细胞机械功能的影响。此外，还将确定铰链、假底物和激活环结构域中酪氨酸残基替换为非磷酸化或假磷酸化氨基酸对 PKCd 定位和底物特异性的影响。最后，实验将解决 PKCd 激活是否促进参与调节病理生理过程（肥大或细胞凋亡）的其他信号转导途径的活性。令人信服的初步证据表明 PKCd 特定酪氨酸残基的磷酸化会改变底物特异性，特别是肌钙蛋白 (Tn) 复合物成分此外，磷酸化酪氨酸 (pY) 可能会改变激酶的辅因子需求，从而实现脂质独立活性。结果将提供有关脂质独立活性的新信息。刺激特异性 PKCd 激活和活性以及对心肌丝磷酸化和肌细胞功能的影响。