Developmental regulation of focal contact protein expression in human melanocytes.
Developmental regulation of focal contact protein expression in human melanocytes.
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人类黑素细胞中焦点接触蛋白表达的发育调节。
DOI：
10.1111/j.1600-0749.1995.tb00667.x
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发表时间：
1995
期刊：
影响因子：
--
通讯作者：
Cassidy,LL
中科院分区：
文献类型：
--
作者：
Scott,GA;Liang,H;Cassidy,LL
焦点接触是细胞外基质和肌动蛋白细胞骨架之间的跨膜连接，在定向细胞迁移、粘附和正常生长中发挥着关键作用。焦点接触的几种不同组成蛋白显示出发育依赖性的表达变化，表明这是胚胎发生过程中控制焦点接触形成的重要机制。在本报告中，我们使用蛋白质印迹法检查了人类胎儿和新生儿黑素细胞中焦点接触相关蛋白的表达。我们发现，桩蛋白（一种 69-kDa 纽蛋白结合蛋白）的表达在新生儿黑素细胞中比在胎儿黑素细胞中高四倍。此外，我们还发现，talin（一种将整合素连接到肌动蛋白细胞骨架的高分子量结构蛋白）在胎儿中被蛋白水解裂解，但在新生儿黑素细胞中则不然。对纤连蛋白上生长的细胞进行免疫荧光显微镜检查，证实在黑色素细胞中推定的焦点接触处的肌动蛋白应力纤维末端存在桩蛋白、踝蛋白和纽蛋白。细胞外基质配体的粘附实验揭示了胎儿和新生儿黑素细胞对纤连蛋白的粘附存在显着差异。观察到的焦点接触蛋白表达的发育特异性变化表明，这可能是人类黑素细胞在发育过程中控制焦点接触组装的重要机制。
Focal contacts are transmembrane links between the extracellular matrix and the actin cytoskeleton that play a critical role in directed cell migration, adhesion, and normal growth. Several different component proteins of the focal contact show develop‐mentally dependent changes in expression, suggesting that this is an important mechanism by which focal contact formation is controlled during embryogenesis. In this report we examine the expression of focal contact‐associated proteins in human fetal and neonatal melanocytes using Western blotting. We show that expression of paxillin, a 69‐kDa vinculin binding protein, is fourfold higher in neonatal melanocytes than in fetal melanocytes. Further, we show that talin, a high molecular weight structural protein that links integrins to the actin cytoskeleton, is proteolytically cleaved in fetal, but not in neonatal melanocytes. Immunofluorescence microscopy of cells grown on fibronectin confirmed the presence of paxillin, talin, and vinculin at the ends of actin stress fibers at presumptive focal contacts in melanocytes. Adhesion experiments to extracellular matrix ligands revealed significant differences in adhesion of fetal and neonatal melanocytes to fibronectin. The developmentally specific changes in focal contact protein expression observed suggest that this may be an important mechanism by which focal contact assembly is controlled in human melanocytes during development.