Degraded collagen fragments promote rapid disassembly of smooth muscle focal adhesions that correlates with cleavage of pp125(FAK), paxillin, and talin.
Degraded collagen fragments promote rapid disassembly of smooth muscle focal adhesions that correlates with cleavage of pp125(FAK), paxillin, and talin.
复制标题
退化的胶原蛋白片段可促进平滑肌局灶性粘附的快速拆卸，与PP125（FAK），Paxillin和Talin的切割相关。
DOI：
10.1083/jcb.147.3.619
复制
发表时间：
1999-11-01
影响因子：
7.8
通讯作者：
Raines, E W
中科院分区：
文献类型：
--
作者：
Carragher, N O;Levkau, B;Ross, R;Raines, E W
在疾病状态如动脉粥样硬化中观察到活性基质金属蛋白酶和降解的胶原。为了研究降解的胶原片段是否对血管平滑肌细胞（SMC）有明显的影响，将胶原酶消化的I型胶原加入培养的人动脉SMC中。加入胶原片段后，粘附的SMC失去其局部粘附结构并变圆。粘着斑复合物的成分分析表明粘着斑激酶（pp125FAK）、桩蛋白和塔林蛋白的快速裂解。蛋白水解酶钙蛋白酶I抑制剂可抑制切割。体外翻译的pp125FAK是钙蛋白酶I和II介导的加工的底物。PP125 FAK的蛋白水解裂解片段的映射预测了粘着斑靶向（FAT）序列和第二个富含脯氨酸的结构域从酪氨酸激酶结构域和整合素结合序列的解离。免疫共沉淀研究证实，与桩蛋白，黏着斑蛋白，和p130cas的pp125 FAK的能力，是显着降低SMC与降解的胶原蛋白片段处理。此外，有一个完整的pp125FAK与细胞骨架部分的关联显着减少，而pp125FAK裂解片段出现在细胞质中的SMC与降解的胶原蛋白片段处理。整合素阻断研究表明，整合素介导的信号参与降解胶原诱导pp125FAK裂解。因此，胶原片段诱导不同的整合素信号，导致钙蛋白酶介导的pp125FAK、桩蛋白和talin裂解的启动和粘着斑复合物的溶解。
Active matrix metalloproteinases and degraded collagen are observed in disease states, such as atherosclerosis. To examine whether degraded collagen fragments have distinct effects on vascular smooth muscle cells (SMC), collagenase-digested type I collagen was added to cultured human arterial SMC. After addition of collagen fragments, adherent SMC lose their focal adhesion structures and round up. Analysis of components of the focal adhesion complex demonstrates rapid cleavage of the focal adhesion kinase (pp125FAK), paxillin, and talin. Cleavage is suppressed by inhibitors of the proteolytic enzyme, calpain I. In vitro translated pp125FAK is a substrate for both calpain I– and II–mediated processing. Mapping of the proteolytic cleavage fragments of pp125FAK predicts a dissociation of the focal adhesion targeting (FAT) sequence and second proline-rich domain from the tyrosine kinase domain and integrin-binding sequence. Coimmunoprecipitation studies confirm that the ability of pp125FAK to associate with paxillin, vinculin, and p130cas is significantly reduced in SMC treated with degraded collagen fragments. Further, there is a significant reduction in the association of intact pp125FAK with the cytoskeletal fraction, while pp125FAK cleavage fragments appear in the cytoplasm in SMC treated with degraded collagen fragments. Integrin-blocking studies indicate that integrin-mediated signals are involved in degraded collagen induction of pp125FAK cleavage. Thus, collagen fragments induce distinct integrin signals that lead to initiation of calpain-mediated cleavage of pp125FAK, paxillin, and talin and dissolution of the focal adhesion complex.