Phosphorylation of moesin by Rho-associated kinase (Rho-kinase) plays a crucial role in the formation of microvilli-like structures
Phosphorylation of moesin by Rho-associated kinase (Rho-kinase) plays a crucial role in the formation of microvilli-like structures
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DOI：
10.1074/jbc.273.52.34663
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发表时间：
1998-12-25
影响因子：
4.8
通讯作者：
Kaibuchi, K
中科院分区：
文献类型：
--
作者：
Oshiro, N;Fukata, Y;Kaibuchi, K
Rho相关激酶(Rho-kinaseRho)被小的GTP酶Rho激活，在体外使苏氨酸(558)处的moesin磷酸化。在这里，使用位点和磷酸化状态特异性抗体，我们发现在COS7细胞中表达显性活性RhoA诱导Moesin磷酸化和顶膜微绒毛样结构的形成，其中Thr(558)磷酸化的Moesin积累，而显性负Rho-Kinase的表达抑制这两个过程。显性活性Rho-Kinase的表达也诱导了Moesin的磷酸化。在去血清条件下培养表达moesin或moesin(T558A)(Ala替代Thr)的COS7细胞，可见少量微绒毛样结构，而表达moesin(T558D)(Asp替代Thr)的COS7细胞仍有微绒毛样结构。MoesinT558A的表达抑制了RhoA诱导的微绒毛样结构的形成。这些结果表明，Rho-Kinase在体内调节Rho下游Moesin的磷酸化，并且Rho-Kinase对Moesin的磷酸化在微绒毛样结构的形成中起着至关重要的作用。
Rho-associated kinase (Rho-kinase), which is activated by the small GTPase Rho, phosphorylates moesin at Thr(558) in vitro. Here, using a site- and phosphorylation state-specific antibody, we found that the expression of dominant active RhoA in COS7 cells induced moesin phosphorylation and the formation of microvilli-like structures at apical membranes where the Thr(558)-phosphorylated moesin accumulated, whereas the expression of dominant negative Rho-kinase inhibited both of these processes. The expression of dominant active Rho-kinase also induced moesin phosphorylation. When COS7 cells expressing moesin or moesin(T558A) (substitution of Thr by Ala) were cultured under serum-depleted conditions, there were few microvilli-like structures, whereas microvilli-like structures remained in the cells expressing moesin(T558D) (substitution of Thr by Asp). The expression of moesinT558A inhibited the dominant active RhoA-induced formation of microvilli-like structures. These results indicate that Rho-kinase regulates moesin phosphorylation downstream of Rho in vivo and that the phosphorylation of moesin by Rho-kinase plays a crucial role in the formation of microvilli-like structures.