Hairy-Related Factors in Cardiac Development and Disease

心脏发育和疾病中与毛发相关的因素

• 批准号: 7118716
• 负责人: ISABELLE N KING
• 金额: $ 10.48万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-09-05 至 2010-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7118716
• 关键词: DNA binding protein; acetylation; alanine; cardiogenesis; chromatin; congenital heart disorder; gene expression; gene mutation; genetic regulation; genetic susceptibility; genetically modified animals; laboratory mouse; molecular genetics; molecular site; protein kinase; protein protein interaction; protein structure function; tissue /cell culture; transcription factor; yeast two hybrid system; DNA binding protein; acetylation; alanine; cardiogenesis; chromatin; congenital heart disorder; gene expression; gene mutation; genetic regulation; genetic susceptibility; genetically modified animals; laboratory mouse; molecular genetics; molecular site; protein kinase; protein protein interaction; protein structure function; tissue /cell culture; transcription factor; yeast two hybrid system

DESCRIPTION (provided by applicant): Congenital heart defects (CHDs) are the leading non-infectious cause of death in the first year of life; however, the etiology of most lesions is unknown. Hairy-related transcription factors (Hrt1, Hrt2 and Hrt3) are transcriptional repressors that are expressed in the somites, cardiac outflow tract, pulmonary arteries, and have mutually exclusive expression domains in the atria and ventricles. We found that Hrt2 forms a complex with Gata4, a transcription factor necessary for normal human cardiac development, that results in repression of Gata4 transactivation. Hrt2 repression of Gata4 was disrupted by the kinase Akt1. We have also identified mutations in the coding regions of Hrt2 in patients with congenital heart disease that suggest a novel Hrt domain necessary for repression. We hypothesize that (1) Hrt2's negative regulation of Gata4-dependent transactivation is sensitive to a growth signal, and (2) that mutations in Hrt2 found in patients with congenital heart malformations reveal a novel and critical domain for Hrt function during cardiogenesis. The specific aims to be addressed in this proposal include: Specific Aim 1: To elucidate the biologic significance of the Hrt2-Gata4 complex and the mechanism(s) by which Hrt2-mediated repression of GATA-dependent cardiac gene expression is sensitive to Akt1. We will study the functional consequences of Hrt2 on chromatin acetylation of endogenous GATA-dependent cardiac genes and examine the role of the orange domain in mediating Akt1-responsive protein-protein interactions. Specific Aim 2: To determine the mechanisms by which clustered human HRT2 mutations found in CHDs affect Hrt2 function. We will conduct detailed in vitro assays to identify co-factors dependent on this novel domain, and we will generate mice harboring these mutations to study their functional consequences in vivo.

描述（由申请人提供）： 先天性心脏缺陷（CHD）是生命第一年的主要非感染死亡原因；但是，大多数病变的病因尚不清楚。 与毛茸茸的转录因子（HRT1，HRT2和HRT3）是在体积中表达的转录阻遏物，心脏流出道，肺动脉，并且在心房和心室中具有相互排斥的表达结构域。 我们发现HRT2与GATA4（正常人类心脏发育所必需的转录因子）形成复合物，从而导致GATA4反式激活抑制。 GATA4的HRT2抑制被激酶AKT1破坏。 我们还确定了先天性心脏病患者HRT2的编码区域中的突变，这表明抑制必要的新型HRT结构域。 我们假设（1）HRT2对GATA4依赖性反式激活的阴性调节对生长信号敏感，并且（2）在先天性心脏畸形患者中发现的HRT2突变揭示了心脏病发生过程中HRT功能的新颖和关键结构域。 本提案中要解决的具体目的包括： 具体目的1：阐明HRT2-GATA4复合物的生物学意义以及HRT2介导的抑制GATA依赖性心脏基因表达对AKT1敏感的机制。 我们将研究HRT2对内源性GATA依赖性心脏基因染色质乙酰化的功能后果，并研究橙色结构域在介导Akt1反应性蛋白质蛋白相互作用中的作用。 具体目标2：确定CHD中发现的人类HRT2突变影响HRT2功能的机制。 我们将进行详细的体外测定法，以确定取决于这个新领域的共同因素，我们将生成具有这些突变的小鼠，以研究其在体内的功能后果。