Suppression of ultraviolet irradiation-induced apoptosis by overexpression of focal adhesion kinase in Madin-Darby canine kidney cells
Suppression of ultraviolet irradiation-induced apoptosis by overexpression of focal adhesion kinase in Madin-Darby canine kidney cells
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DOI：
10.1074/jbc.274.38.26901
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发表时间：
1999-09-17
影响因子：
4.8
通讯作者：
Chen, HC
中科院分区：
文献类型：
--
作者：
Chan, PC;Lai, JF;Chen, HC
粘着斑激酶(FAK)被认为具有抑制细胞凋亡的作用。在本研究中，我们证明了紫外光照射可诱导Madin-Darby犬肾细胞FAK及其两个相互作用蛋白Src和p130(Cas)的裂解，并伴随细胞死亡的增加。Caspase的广谱抑制剂zVAD-FMK可完全抑制这些蛋白在紫外线照射下的切割，而bcl2的过表达则明显延缓了这些蛋白的切割。为了研究FAK是否在抑制紫外线诱导的细胞凋亡中起作用，建立了稳定表达FAK的犬肾细胞系Madin-Darby。我们的结果表明，通过这种策略，细胞在紫外线照射下的存活率显著提高(30%-40%)。在我们努力确定FAK将生存信号传导到下游的机制时，我们发现一个与磷脂酰肌醇3-激酶结合不足的PAK突变体未能促进细胞存活。此外，与内源性p130(Cas)竞争FAK结合的p130(Cas)的Src同源3结构域的表达取消了FAK促进的细胞存活。综上所述，这些结果表明，FAK的完整性及其与磷脂酰肌醇3-激酶和p130(Cas)的结合是FAK发挥抗凋亡功能所必需的。
Focal adhesion kinase (FAK) has been implicated tea play a role in suppression of apoptosis. In this study, we have demonstrated that UV irradiation induced cleavage of FAK and two of its interacting proteins Src and p130(Cas) in Madin-Darby canine kidney cells, concomitant with an increase in cell death. The cleavage of these proteins upon UV irradiation was completely inhibited by ZVAD-FMK, a broad range inhibitor of caspases, and apparently delayed by Bcl2 overexpression. To examine if FAK plays a role in suppressing UV-induced apoptosis, stable Madin-Darby canine kidney cell lines overexpressing FAK were established. Our results showed that a marked (30-40%) increase in cell survival upon UV irradiation was achieved by this strategy. In our efforts to determine the mechanism by which FAK transduces survival signals to the downstream, we found that a PAK mutant deficient in binding to phosphatidylinositol 3-kinase failed to promote cell survival. Moreover, the expression of the Src homology 3 domain of p130(Cas), which competed with endogenous p130(Cas) for FAK binding, abrogated the FAK-promoted cell survival. Together, these results suggest that the integrity of FAK and its binding to phosphatidylinositol 3-kinase and p130(Cas) are required for FAK to exert its antiapoptotic function.