Cellular redistribution of PKCα, rhoA, and ROKα following smooth muscle agonist stimulation
Cellular redistribution of PKCα, rhoA, and ROKα following smooth muscle agonist stimulation
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DOI：
10.1006/excr.1999.4565
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发表时间：
1999-08-25
影响因子：
3.7
通讯作者：
Morgan, KG
中科院分区：
文献类型：
--
作者：
Taggart, MJ;Lee, YH;Morgan, KG
有效的受体偶联激活平滑肌需要从质膜到肌丝的许多信号转导事件的离散协调。质膜上关键因子的募集被认为是导致收缩的细胞外信号转导的关键。因此，我们首次研究了在完整分化的平滑肌细胞中，对受体偶联兴奋重要的三个分子的分布：蛋白激酶Cα(PKCα)、RhoA和Rho Kinase(ROK)。我们还通过单细胞测力直接证实了氨基甲胆碱诱导的[Ca~(2+)](I)对收缩的敏化作用。中央平滑肌细胞切片的激光扫描共聚焦免疫荧光显微镜显示，静息状态下，PKCα、RhoA和ROKα主要分布在胞浆中。毒扁豆碱刺激导致每种蛋白质显著地重新分布到细胞膜。经数字图像分析，静息时PKCα、RhoA和ROKα的胞浆分布分别为1.05+/-0.03(8)、1.09+/-0.03(5)和1.26+/-0.04(12)，刺激后显著增加至2.09+/-0.22(6)、2.02+/-0.12(8)和1.93+/-0.05(10)。有人认为，受体偶联的下游信号分子PKCα、RhoA和Roka在细胞外周的募集有助于激动剂诱导的平滑肌收缩激活的效果。(C)1999年学术出版社。
Efficient receptor-coupled activation of smooth muscle requires discrete coordination of many signal transducing events from the plasma membrane to the myofilaments. Recruitment of key factors to the plasma membrane is thought to be crucial for transduction of extracellular signals leading to contractility. We investigated, therefore, for the first time in intact differentiated smooth muscle cells; the distributions of three molecules important for receptor-coupled excitation: protein kinase C alpha (PKC alpha), rhoA, and rho kinase (ROK). We also directly confirmed, by single cell force measurements, carbachol-induced [Ca2+](i) sensitization of contractility.. Laser scanning confocal immunofluorescent microscopy of central smooth muscle cell sections determined that, at rest, PKC alpha, rhoA, and ROK alpha were distributed predominantly throughout the cytosol. Muscarinic stimulation resulted in significant redistribution of each protein to the cell membrane. By digital image analysis, peripheral:cytosolic distributions of PKC alpha, rhoA, and ROK alpha were calculated as, respectively, 1.05 +/- 0.03 (8), 1.09 +/- 0.03 (5), and 1.26 +/- 0.04 (12) at rest, increasing significantly following stimulation to 2.09 +/- 0.22 (6), 2.02 +/- 0.12 (8), and 1.93 +/- 0.05 (10). It is proposed that this receptor-coupled recruitment to the cell periphery of the downstream signaling molecules PKC alpha, rhoA, and ROK alpha contributes to the efficacy of agonist-induced contractile activation of smooth muscle. (C) 1999 Academic Press.