Satoh K, Ozaki Y, Asazuma N, Yatomi Y, Ruomei Q, Kuroda K, Yang L, Kume S
Department of Clinical and Laboratory Medicine, Yamanashi Medical University, Japan.
Biochem Biophys Res Commun. 1996 Aug 23;225(3):1084-9. doi: 10.1006/bbrc.1996.1299.
Both thrombin and thrombin receptor agonist peptide (TRAP) activated p72syk and p60c-src with similar magnitudes. Both thrombin and TRAP induced translocation of p60c-src and p54/58lyn to cytoskeleton in an aggregation-dependent manner. Thrombin also induced cytoskeletal association of p72syk, but independent of platelet aggregation. Furthermore, p72syk associated with cytoskeleton underwent marked proteolysis, which was partially dependent upon calpain activation. In contrast, TRAP, even at concentrations as high as 100 mu M, did not induce p72syk translocation to cytoskeleton. Our findings suggest that cytoskeletal translocation of p72syk induced by thrombin is governed by a mechanism distinct from those of p60c-src and p54/58lyn translocation. It is also suggested that p72syk translocation induced by thrombin requires additional signal(s) other than that mediated by the recently-cloned thrombin receptor that couples with GTP-binding proteins and interacts with TRAP.
凝血酶和凝血酶受体激动肽（TRAP）均以相似的程度激活p72syk和p60c-src。凝血酶和TRAP均以聚集依赖的方式诱导p60c-src和p54/58lyn向细胞骨架的转位。凝血酶还诱导p72syk与细胞骨架结合，但不依赖于血小板聚集。此外，与细胞骨架结合的p72syk发生明显的蛋白水解，这部分依赖于钙蛋白酶的激活。相比之下，即使在高达100μM的浓度下，TRAP也不会诱导p72syk向细胞骨架的转位。我们的研究结果表明，凝血酶诱导的p72syk向细胞骨架的转位受一种不同于p60c-src和p54/58lyn转位的机制支配。还表明，凝血酶诱导的p72syk转位需要除最近克隆的与GTP结合蛋白偶联并与TRAP相互作用的凝血酶受体介导的信号之外的其他信号。
