MLC Dephosphorylation in Smooth Muscle Cell Apoptosis

平滑肌细胞凋亡中的 MLC 去磷酸化

• 批准号: 6486367
• 负责人: Fabeha Fazal
• 金额: $ 5.44万
• 依托单位: UNIVERSITY OF ILLINOIS AT CHICAGO
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-06-28 至 2003-06-27
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6486367
• 关键词: apoptosis; cell growth regulation; cytokine; cytoskeleton; enzyme induction /repression; enzyme inhibitors; intermolecular interaction; myosin light chain kinase; myosins; phosphorylation; postdoctoral investigator; protein structure function; swine; tissue /cell culture; vascular smooth muscle; western blottings

The cytoskeleton undergoes dramatic changes during programmed cell death (apoptosis) and actin has been implicated in mediating these cytoskeletal changes. Although actin and myosin II work in concert, little is known about the role of myosin II and its regulation by myosin light chain phosphorylation in the mechanism of smooth muscle cell apoptosis. We have made three observations that impact the regulation of cytoskeletal dynamics during apoptosis. First, myosin light chains are dephosphorylated during apoptosis; Second, the activity of myosin light chain kinase (MLCK), the enzyme that phosphorylates myosin II, is decreased during apoptosis; First, myosin light chains are dephosphorylated during apoptosis. Second, the activity of myosin light chain kinase (MLCK), the enzyme that phosphorylates myosin II, is decreased during apoptosis; Second, the activity of myosin light chain kinase (MLCK), the enzyme that phosphorylates myosin II, is decreased during apoptosis; Third, prolonged inhibition of MLCK activity using a pharmacological agent results in nuclear fragmentation and genome digestion. Based on these data, I propose the hypothesis that myosin light chain dephosphorylation is necessary for and perhaps initiates the cytoskeletal changes characteristic of programmed cell death. Specifically, I will address the role of MLCK dephosphorylation in vascular smooth muscle cell death and determine how this may be regulated at the molecular level. The specific aims of this proposal are to: 1. Establish the relation between myosin light chain dephosphorylation and apoptosis of smooth muscle cells. 2. Determine the function of "non-apoptotic MLCK dephosphorylation" in sensitizing the smooth muscle cells to undergo apoptosis following exposure to the pro-inflammatory cytokines TNF-alpha, IL-1beta and IFN-gamma. The information derived from these studies will increase our understanding of cytoskeletal dynamics during apoptosis.

在程序性细胞死亡（凋亡）期间，细胞骨架发生了巨大变化，肌动蛋白与介导这些细胞骨架变化有关。尽管肌动蛋白和肌球蛋白II在一致之间起作用，但对肌球蛋白II的作用及其通过肌球蛋白轻链磷酸化在平滑肌细胞凋亡机理中的作用知之甚少。我们进行了三个观察结果，这些观察会影响细胞凋亡过程中细胞骨架动力学的调节。首先，肌球蛋白光链在凋亡过程中被脱磷酸化。其次，肌球蛋白轻链激酶（MLCK）的活性是磷酸化肌球蛋白II的酶，在凋亡过程中降低。首先，肌球蛋白光链在凋亡过程中被脱磷酸化。其次，肌球蛋白轻链激酶（MLCK）的活性是磷酸化肌球蛋白II的酶，在凋亡过程中降低。其次，肌球蛋白轻链激酶（MLCK）的活性是磷酸化肌球蛋白II的酶，在凋亡过程中降低。第三，使用药理剂长期抑制MLCK活性会导致核破坏和基因组消化。基于这些数据，我提出了以下假设：肌球蛋白轻链去磷酸化是必要的，也许启动了程序性细胞死亡的细胞骨架变化特征。具体而言，我将解决MLCK去磷酸化在血管平滑肌细胞死亡中的作用，并确定如何在分子水平调节这一点。该提案的具体目的是：1。建立肌球蛋白轻链去磷酸化和平滑肌细胞凋亡之间的关系。 2。确定“非凋亡MLCK去磷酸化”在暴露于促炎性细胞因子TNF-Alpha，IL-1Beta和Ifn-Gamma后的平滑肌细胞敏感性中的功能。从这些研究中得出的信息将增加我们对凋亡过程中细胞骨架动力学的理解。