GENETIC ANALYSIS OF BETA SUBUNIT OF THE CARDIAC L-TYPE VDCC

L型电压依赖性钙通道（VDCCs）是钙离子通道的重要组成部分 心脏功能的调节。 的动力学特性 这些通道，这是重要的控制心率和力量的 收缩，由四个亚基的一级序列定义， 组成每个频道。 本提案的目的是确定 L型VDCCs三种β亚单位的心内分布 存在于心脏中，并确定β亚基在心脏中的作用。 调节工作心肌中存在的L型VDCC。 具体目标是：1）分离和表征小鼠cDNA， 来自β 2和β 3亚基基因的基因组克隆，2）以确定 β 1、β 2和β 3亚基的原位分布 杂交和免疫组织化学检测。 3)使用 基因靶向，以产生缺乏β亚基的小鼠， 主要在工作心肌中表达，以及4）表征 这种β无效突变对心肌细胞L型VDCC的影响 以及完整动物的生理机能。 特别修改的beta 亚基将被引入到β无效肌细胞或β无效肌细胞中。 动物，以确定其对心脏L型调节的影响 VDCC。

L-type voltage dependent calcium channels (VDCCs) are critical components in the regulation of cardiac function. The kinetic characteristics of these channels, which are important in controlling heart rate and force of contraction, are defined by the primary sequence of the four subunits that make up each channel. The objectives of this proposal are to determine the intracardiac distribution of the three beta subunits of L-type VDCCs present in the heart, and to determine the role of the beta subunit in the regulation of the L-type VDCC present in working myocardium. The specific aims are; 1) to isolate and characterize murine cDNA and genomic clones from the beta2 and beta3 subunit genes, 2) to determine the distribution of the beta1, beta2 and beta3 subunits by in situ hybridization and immunohistochemical detection in heart sections. 3) use gene targeting, to produce a mouse that lacks the beta subunit that is predominantly expressed in working myocardium, and 4) to characterize the effect of this beta null mutation on the L-type VDCC of cardiac myocytes and on the physiology of the intact animal. Specifically modified beta subunits will be introduced into either beta null myocytes or beta null animals to determine their effect on the regulation of the cardiac L-type VDCC.