Roles of Cypher in Cardiac Muscle

描述(由申请人提供)：这项为期五年的计划的目的是检验这一假设，即Cypher是一种关键的连接蛋白，它通过与α-Actinin 2、PKC、PKA以及潜在的其他Z-线蛋白的相互作用来调节Z线上的结构完整性和信号通路。每种Cypher亚型都有不同的作用，Cypher的D626N突变通过增加Cypher对PKC的亲和力而导致扩张型心肌病(DCM)。这项建议的总体目标是了解Cypher及其异构体在心脏功能中的作用，并深入了解D626N突变导致DCM的机制。我们将通过对现有的几个基因操纵的小鼠品系以及正在制作的小鼠品系的心脏表型进行全面的组织学、生化和生理学分析来实现这些目标。因此，具体目的是：1.了解Cypher在心脏中的功能作用。我们将通过分析两个小鼠品系来研究Cypher在心脏中的功能。在这两个品系中，Cypher在发育中或成年心脏中被选择性地消融。2.确定长Cypher剪接异构体Cypher 1和短Cypher剪接异构体Cypher 2的生物学功能。我们将通过详细分析两个小鼠品系来研究长Cypher亚型和短Cypher亚型的功能，在这两个品系中，每个亚型都被选择性地去除。3.了解Cypher与PKC的相互作用在扩张型心肌病中的作用。这些研究将有助于我们在分子、细胞和生理水平上理解Cypher及其异构体的生物学功能。此外，我们还将深入了解Cypher突变导致DCM的机制，从而提高我们对DCM的总体理解。此外，这些小鼠品系将作为潜在疗法的测试模型。

DESCRIPTION (provided by applicant): The aim of this five-year proposal is to test the hypothesis that Cypher is a critical linker protein, which serves to mediate structural integrity and signaling pathways at the Z-line via its interactions with a-actinin 2, PKC, PKA, and potentially other Z-line proteins. Each Cypher isoform has distinct role and the D626N mutation of Cypher results in dilated cardiomyopathy (DCM) through increased affinity of Cypher for PKC. The overall goals of this proposal are to understand the role of Cypher and its isoforms in cardiac function and to gain insight into the mechanisms by which the mutation D626N causes DCM. We will achieve these goals by comprehensive histological, biochemical, and physiological analyses of the cardiac phenotypes of several existing genetically manipulated mouse lines as well as mouse lines in the process of being made. Accordingly, the Specific Aims are: 1. To understand the functional role of Cypher in heart. We will investigate the function of Cypher in heart by analyzing two mouse lines in which Cypher is selectively ablated in developing or adult heart. 2. To determine the biological function of long and short Cypher splice isoforms, Cypher1 and Cypher2, respectively. We will investigate the function of long and short Cypher isoforms by analyzing in detail two mouse lines in which each isoform is selectively ablated. 3. To understand the role of Cypher's interaction with PKC in DCM. The proposed studies will help us to understand the biological function of Cypher and its isoforms at molecular, cellular, and physiological levels. Furthermore, we will gain insight into the mechanisms by which mutations in Cypher causes DCM, thereby improving our general understanding of DCM. In addition, the mouse lines will be useful as test models for potential therapies.