MAPK IN THE CONTRACTILE PHENOTYPE OF SMOOTH MUSCLE

平滑肌收缩表型中的 MAPK

基本信息

批准号：
6165064
负责人：
JOHN A BADWEY
金额：
$ 24.1万
依托单位：
BOSTON BIOMEDICAL RESEARCH INSTITUTE
依托单位国家：
美国
项目类别：
财政年份：
1996
资助国家：
美国
起止时间：
1996-03-01 至 2002-02-28
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/6165064
关键词：
actins adenosinetriphosphatase animal tissue caldesmon carotid artery chemical binding enzyme activity mitogen activated protein kinase muscle contraction muscle stress myosins phosphorylation vascular smooth muscle

项目摘要

DESCRIPTION: (Investigator's abstract) The goal of the work outlined in this application is to further understanding of the signalling systems in vascular smooth muscle that result in an alteration of contractility. In particular, studies are proposed to investigate the roles of mitogen-activated protein kinase (MAPK) and caldesmon in vascular smooth muscle contraction. The high molecular weight form of caldesmon (h-caldesmon) is a potent, smooth muscle specific, inhibitor of actomyosin ATPase activity, in vitro, that binds both actin and myosin. h-Caldesmon is phosphorylated in resting porcine carotid arteries and the stoichiometry of phosphorylation increases in response to pharmacological stimulation suggesting that this process may be regulatory for contraction. h- Caldesmon is phosphorylated on two sites in the carboxyl-terminus of the protein; these sites are modified by mitogen-activated protein kinase (MAPK), in vitro. The hypothesis to be tested is that the activation of MAPK is the contractile phenotype of smooth muscle results in the phosphorylation of h-caldesmon and an alteration of contractile function. Two sub-hypotheses to this are that the phosphorylation of h- caldesmon by MAPK 1:alters actomyosin kinetics, either directly or via an interaction with another protein, and 2) allows for structural changes within the cell that are required for prolonged alterations of stress. In order to investigate this hypothesis, the following specific aims will be pursued: 1. To measure MAPK activity, h-caldesmon phosphorylation and force upon pharmacological stimulation of porcine carotid arteries. Agonists will include neurohumoral agents and growth factors. 2. To measure MAPK activity and h-caldesmon phosphorylation in porcine carotid arteries subjected to stretch. MAPK activity and h-caldesmon phosphorylation levels will be measured as a function of mechanical load applied to the muscle. 3. To determine the biochemical effects of h-caldesmon phosphorylation by MAPK on a)actin and myosin binding to h-caldesmon, b) actin polymerization, and c) actomyosin ATPase activity. Studies in this aim will investigate the direct biochemical effects of h-caldesmon phosphorylation on the contractile apparatus. MAPK plays a role in cultured cell growth and proliferation; however, cells in the contractile phenotype of vascular smooth muscle do not normally undergo cell division. These studies are unique in investigating involvement of MAPK in smooth muscle contractility, the primary function of this tissue.

描述：（研究者的摘要）概述的工作目标在这个应用中是为了进一步理解信令血管平滑肌中的系统会导致收缩性。特别是，建议进行研究以调查丝裂原激活蛋白激酶 (MAPK) 和 caldesmon 在血管平滑肌收缩。高分子量形式的卡地斯蒙 (h-caldesmon) 是一种有效的、平滑肌特异性、肌动球蛋白 ATP 酶活性抑制剂体外，结合肌动蛋白和肌球蛋白。 h-Caldesmon 被磷酸化静息猪颈动脉和化学计量磷酸化因药理刺激而增加表明这个过程可能是收缩的调节过程。 h- Caldesmon 在羧基末端的两个位点被磷酸化蛋白质;这些位点被丝裂原激活蛋白激酶修饰（MAPK），体外。要测试的假设是激活 MAPK 是平滑肌的收缩表型结果 h-caldesmon 的磷酸化和收缩力的改变功能。对此的两个子假设是 h- 的磷酸化 caldesmon by MAPK 1：直接或通过改变肌动球蛋白动力学与另一种蛋白质的相互作用，2）允许结构细胞内的变化是长时间改变所必需的压力。为了验证这一假设，具体如下：将追求的目标是： 1. 测量 MAPK 活性、h-caldesmon 磷酸化和作用力对猪颈动脉的药理刺激。激动剂将包括神经体液剂和生长因子。 2. 测定猪MAPK活性和h-caldesmon磷酸化颈动脉受到拉伸。 MAPK 活性和 h-caldesmon 磷酸化水平将作为机械负载的函数进行测量应用于肌肉。 3. 确定h-caldesmon磷酸化的生化效应通过 MAPK 对 a) 肌动蛋白和肌球蛋白与 h-caldesmon 结合，b) 肌动蛋白聚合，和c)肌动球蛋白ATP酶活性。以此为目标的研究将研究 h-caldesmon 的直接生化效应收缩装置的磷酸化。 MAPK 在培养细胞的生长和增殖中发挥作用；然而，血管平滑肌收缩表型的细胞不通常进行细胞分裂。这些研究的独特之处在于研究 MAPK 在平滑肌收缩力中的参与该组织的主要功能。