Analysis of PINCH function in Drosophila demonstrates its requirement in integrin-dependent cellular processes
Analysis of PINCH function in Drosophila demonstrates its requirement in integrin-dependent cellular processes
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DOI：
10.1242/dev.00492
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发表时间：
2003-06-01
期刊：
影响因子：
4.6
通讯作者：
Beckerle, MC
中科院分区：
文献类型：
--
作者：
Clark, KA;McGrail, M;Beckerle, MC
整合素在细胞运动、细胞增殖和细胞存活中起着至关重要的作用。进化上保守的LIM蛋白Pinch被认为是整合素依赖的信号复合体的一部分。为了评估PIPCH在整合素介导的细胞事件中的作用，我们直接在果蝇体内测试了PINCH的功能。我们证明，在筛选潜在的整合素效应器时首次发现的蒸鸭(STCK)等位基因代表了果蝇夹带的突变。STCK突变体在胚胎发育过程中死亡，揭示了Pinch在发育中的关键作用。收缩功能受损的胚胎中的肌肉细胞表现出肌动蛋白组织紊乱和细胞-基质黏附。STCK突变也会导致机翼整合素依赖的上皮细胞黏附失败。与Pinch可能有助于整合素功能的想法一致，Pinch蛋白与PPS整合素共同定位于肌肉和翼上皮细胞中肌动蛋白细丝锚定的位置。此外，我们还发现整合素对于肌腱连接处收缩的正确定位是必需的。整合素连接的激酶，ILK，对整合素的功能也是必不可少的。我们证明了果蝇PINCH和ILK在体内是复杂的，并在胚胎肌肉中富含整合素的肌肉附着位置重合。有趣的是，ILK在STCK突变的胚胎中有适当的定位，因此STCK突变的表型不能归因于ILK的错误定位。我们的结果提供了直接的遗传学证据，证明PINCH对果蝇的发育是必不可少的，并且是整合素依赖的细胞黏附所必需的。
Integrins play a crucial role in cell motility, cell proliferation and cell survival. The evolutionarily conserved LIM protein PINCH is postulated to act as part of an integrin-dependent signaling complex. In order to evaluate the role of PINCH in integrin-mediated cellular events, we have tested directly the in vivo function of PINCH in Drosophila melanogaster. We demonstrate that the steamer duck (stck) alleles that were first identified in a screen for potential integrin effectors represent mutations in Drosophila pinch. stck mutants die during embryogenesis, revealing a key role for PINCH in development. Muscle cells within embryos that have compromised PINCH function display disturbed actin organization and cell-substratum adhesion. Mutation of stck also causes failure of integrin-dependent epithelial cell adhesion in the wing. Consistent with the idea that PINCH could contribute to integrin function, PINCH protein colocalizes; with PPS integrin at sites of actin filament anchorage in both muscle and wing epithelial cells. Furthermore, we show that integrins are required for proper localization of PINCH at the myotendinous junction. The integrin-linked kinase, ILK, is also essential for integrin function. We demonstrate that Drosophila PINCH and ILK are complexed in vivo and are coincident at the integrin-rich muscle-attachment sites in embryonic muscle. Interestingly, ILK localizes appropriately in stck mutant embryos, therefore the phenotypes exhibited by the stck mutants are not attributable to mislocalization of ILK. Our results provide direct genetic evidence that PINCH is essential for Drosophila development and is required for integrin-dependent cell adhesion.