钙振荡触发人U87星形细胞瘤细胞中的粘着斑解体。

Calcium oscillations trigger focal adhesion disassembly in human U87 astrocytoma cells.

作者信息

Giannone Gregory, Rondé Philippe, Gaire Mireille, Haiech Jacques, Takeda Kenneth

机构信息

Laboratoire de Pharmacologie et Physicochimie des Interactions Cellulaires et Moléculaires, UMR CNRS 7034, Université Louis Pasteur de Strasbourg, 67401 Illkirch, France.

出版信息

J Biol Chem. 2002 Jul 19;277(29):26364-71. doi: 10.1074/jbc.M203952200. Epub 2002 May 14.

Abstract

Integrin-associated intracellular Ca(2+) oscillations modulate cell migration, probably by controlling integrin-mediated release of the cell rear during migration. Focal adhesion kinase (FAK), via its tyrosine phosphorylation activity, plays a key role in integrin signaling. In human U87 astrocytoma cells, expression of the dominant negative FAK-related non-kinase domain (FRNK) inhibits the Ca(2+)-sensitive component of serum-dependent migration. We investigated how integrin-associated Ca(2+) signaling might be coupled to focal adhesion (FA) dynamics by visualizing the effects of Ca(2+) spikes on FAs using green fluorescent protein (GFP)-tagged FAK and FRNK. We report that Ca(2+) spikes are temporally correlated with movement and disassembly of FAs, but not their formation. FRNK transfection did not affect generation of Ca(2+) spikes, although cell morphology was altered, with fewer FAs of larger size and having a more peripheral localization being observed. Larger sized FAs in FRNK-transfected cells were not disassembled by Ca(2+) spikes, providing a possible explanation for impaired Ca(2+)-dependent migration in these cells. Stress fiber end movements initiated by Ca(2+) spikes were visualized using GFP-tagged myosin light chain kinase (MLCK). Ca(2+)-associated movements of stress fiber ends and FAs had similar kinetics, suggesting that stress fibers and FAs move in a coordinated fashion. This indicates that increases in Ca(2+) likely trigger disassembly of adhesive structures that involves disruption of integrin-extracellular matrix interactions, supporting a key role for Ca(2+)-sensitive inside-out signaling in cell migration. A rapid increase in tyrosine phosphorylation of FAK was found in response to an elevation in Ca(2+) induced by thapsigargin, and we propose that this represents the initial triggering event linking Ca(2+) signaling and FA dynamics to cell motility.

摘要

整合素相关的细胞内钙离子振荡可能通过控制迁移过程中整合素介导的细胞尾部释放来调节细胞迁移。粘着斑激酶(FAK)通过其酪氨酸磷酸化活性在整合素信号传导中起关键作用。在人U87星形细胞瘤细胞中,显性负性FAK相关非激酶结构域(FRNK)的表达抑制血清依赖性迁移的钙离子敏感成分。我们通过使用绿色荧光蛋白(GFP)标记的FAK和FRNK可视化钙离子尖峰对粘着斑(FA)的影响,研究整合素相关的钙离子信号如何与粘着斑动力学耦合。我们报告钙离子尖峰在时间上与粘着斑的移动和拆卸相关,但与它们的形成无关。FRNK转染不影响钙离子尖峰的产生,尽管细胞形态发生了改变,观察到的粘着斑数量减少、尺寸更大且定位更外周。FRNK转染细胞中较大尺寸的粘着斑不会被钙离子尖峰拆卸,这为这些细胞中钙离子依赖性迁移受损提供了一种可能的解释。使用GFP标记的肌球蛋白轻链激酶(MLCK)可视化由钙离子尖峰引发的应力纤维末端运动。应力纤维末端和粘着斑的钙离子相关运动具有相似的动力学,表明应力纤维和粘着斑以协调的方式移动。这表明钙离子的增加可能触发涉及整合素 - 细胞外基质相互作用破坏的粘附结构的拆卸,支持钙离子敏感的由内向外信号在细胞迁移中的关键作用。在毒胡萝卜素诱导的钙离子升高后,发现FAK的酪氨酸磷酸化迅速增加,我们提出这代表了将钙离子信号和粘着斑动力学与细胞运动性联系起来的初始触发事件。

文献AI研究员

20分钟写一篇综述,助力文献阅读效率提升50倍

立即体验

用中文搜PubMed

大模型驱动的PubMed中文搜索引擎

马上搜索