Dynamic conformational changes in the FERM domain of FAK are involved in focal-adhesion behavior during cell spreading and motility
Dynamic conformational changes in the FERM domain of FAK are involved in focal-adhesion behavior during cell spreading and motility
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DOI：
10.1242/jcs.028738
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发表时间：
2009-03-01
影响因子：
4
通讯作者：
Bunt, Gertrude
中科院分区：
文献类型：
--
作者：
Papusheva, Ekaterina;de Queiroz, Fernanda Mello;Bunt, Gertrude
粘着斑激酶（FAK）通过与整合素和细胞外基质介导的信号传导紧密联系来控制细胞的粘附和运动过程。为了探索FAK调控的动力学，我们构建了一个基于FRET的探针，该探针可以可视化活细胞中FAK FERM结构域的构象重排。该传感器报告了细胞粘附后FAK中整合素介导的构象变化。扰动是激酶无关的，涉及FERM结构域中的多元KAKTLR序列。它表现为FRET信号增加，主要在粘着斑中表达，在细胞质中表达程度较低。FAK的FERM结构域中的构象变化在两个连续的阶段中观察到，在扩展过程中-早期和晚期-并且在生长和滑动的外周局灶性粘连位点处的完全粘附的运动细胞中富集，但在稳定或收缩的局灶性粘连中不富集。肌动球蛋白系统的抑制表明参与张力信号诱导的Rho相关激酶，而不是肌球蛋白轻链激酶，在FERM反应的调制。我们的结论是异构构象的FERM域的迁移细胞的粘着斑反映了一个复杂的调控机制FAK，似乎是在细胞牵引力的影响下。
Focal adhesion kinase (FAK) controls cellular adhesion and motility processes by its tight link to integrin- and extracellular-matrix-mediated signaling. To explore the dynamics of the regulation of FAK, we constructed a FRET-based probe that visualizes conformational rearrangements of the FERM domain of FAK in living cells. The sensor reports on an integrin-mediated conformational change in FAK following cellular adhesion. The perturbation is kinase-independent and involves the polybasic KAKTLR sequence in the FERM domain. It is manifested by an increased FRET signal and is expressed primarily in focal adhesions, and to a lesser extent in the cytoplasm. The conformational change in the FERM domain of FAK is observed in two consecutive phases during spreading - early and late - and is enriched in fully adhered motile cells at growing and sliding peripheral focal-adhesion sites, but not in stable or retracting focal adhesions. Inhibition of the actomyosin system indicates the involvement of tension signaling induced by Rho-associated kinase, rather than by myosin light-chain kinase, in the modulation of the FERM response. We conclude that the heterogeneous conformation of the FERM domain in focal adhesions of migrating cells reflects a complex regulatory mechanism for FAK that appears to be under the influence of cellular traction forces.