局部钙升高触发粘着斑解体,并增强粘着斑激酶在粘着斑处的驻留。
Calcium rises locally trigger focal adhesion disassembly and enhance residency of focal adhesion kinase at focal adhesions.
作者信息
Giannone Grégory, Rondé Philippe, Gaire Mireille, Beaudouin Joël, Haiech Jacques, Ellenberg Jan, Takeda Kenneth
机构信息
Laboratoire de Pharmacologie et Physicochimie des Interactions Cellulaires et Moléculaires, Unité Mixte de Recherche CNRS 7034, Université Louis Pasteur de Strasbourg, 67401 Illkirch, France.
出版信息
J Biol Chem. 2004 Jul 2;279(27):28715-23. doi: 10.1074/jbc.M404054200. Epub 2004 Apr 21.
Focal adhesion kinase (FAK) activity and Ca(2+) signaling led to a turnover of focal adhesions (FAs) required for cell spreading and migration. We used yellow Cameleon-2 (Ycam), a fluorescent protein-based Ca(2+) sensor fused to FAK or to a FAK-related non-kinase domain, to measure simultaneously local Ca(2+) variations at FA sites and FA dynamics. Discrete subcellular Ca(2+) oscillators initiate both propagating and abortive Ca(2+) waves in migrating U87 astrocytoma cells. Ca(2+)-dependent FA disassembly occurs when the Ca(2+) wave reaches individual FAs, indicating that local but not global Ca(2+) increases trigger FA disassembly. An unexpectedly rapid flux of FAK between cytosolic and FA compartments was revealed by fluorescence recovery after photobleaching studies. The FAK-Ycam recovery half-time (17 s) at FAs was slowed (to 29 s) by Ca(2+) elevation. FAK-related non-kinase domain-Ycam had a faster, Ca(2+)-insensitive recovery half-time (11 s), which is consistent with the effect of Ca(2+) on FAK-Ycam dynamics not being due to a general modification of the dynamics of FA components. Because FAK association at FAs was prolonged by Ca(2+) and FAK autophosphorylation was correlated to intracellular Ca(2+) levels, we propose that local Ca(2+) elevations increase the residency of FAK at FAs, possibly by means of tyrosine phosphorylation of FAK, thereby leading to increased activation of its effectors involved in FA disassembly.
粘着斑激酶(FAK)活性和Ca(2+)信号传导导致细胞铺展和迁移所需的粘着斑(FAs)周转。我们使用黄色钙黄绿素-2(Ycam),一种与FAK或FAK相关的非激酶结构域融合的基于荧光蛋白的Ca(2+)传感器,来同时测量FA位点处的局部Ca(2+)变化和FA动态。离散的亚细胞Ca(2+)振荡器在迁移的U87星形细胞瘤细胞中引发传播性和流产性Ca(2+)波。当Ca(2+)波到达单个FAs时,Ca(2+)依赖性FA解体发生,这表明局部而非全局Ca(2+)增加触发FA解体。光漂白后荧光恢复研究揭示了FAK在胞质和FA区室之间意外快速的通量。Ca(2+)升高使FAs处的FAK-Ycam恢复半衰期(17秒)减慢(至29秒)。FAK相关的非激酶结构域-Ycam具有更快的、对Ca(2+)不敏感的恢复半衰期(11秒),这与Ca(2+)对FAK-Ycam动态的影响并非由于FA成分动态的一般修饰一致。由于Ca(2+)延长了FAs处FAK的结合,且FAK自磷酸化与细胞内Ca(2+)水平相关,我们提出局部Ca(2+)升高可能通过FAK的酪氨酸磷酸化增加FAK在FAs处的驻留时间,从而导致参与FA解体的效应器激活增加。