CAKbeta和Fyn使Hic-5的酪氨酸60位点发生磷酸化。

Phosphorylation of Hic-5 at tyrosine 60 by CAKbeta and Fyn.

作者信息

Ishino M, Aoto H, Sasaski H, Suzuki R, Sasaki T

机构信息

Department of Biochemistry, Cancer Research Institute, Sapporo Medical University School of Medicine, South-1, West-17, Chuo-Ku, 060-8556, Sapporo, Japan.

出版信息

FEBS Lett. 2000 Jun 2;474(2-3):179-83. doi: 10.1016/s0014-5793(00)01597-0.

DOI:10.1016/s0014-5793(00)01597-0

PMID:10838081

Abstract

Hic-5 is a CAKbeta-binding protein localized at focal adhesions. Here we show that overexpression of CAKbeta or Fyn, but not FAK, enhanced the tyrosine phosphorylation of coexpressed Hic-5 in COS-7 cells. These phosphorylations were further augmented by stimulating cells with osmotic stress. The Y60F mutant of Hic-5 was not phosphorylated, and Hic-5 phosphorylated on tyrosine 60 was bound specifically to the SH2 domain of Csk. Coexpression experiments revealed that the phosphorylation of Hic-5 by CAKbeta required the kinase activation of CAKbeta and binding of Hic-5 by CAKbeta. Specific phosphorylation of Hic-5 by CAKbeta and Fyn may activate a signaling pathway mediated by Hic-5.

摘要

Hic-5是一种定位于粘着斑的CAKβ结合蛋白。在此我们表明，在COS-7细胞中，CAKβ或Fyn（而非FAK）的过表达增强了共表达的Hic-5的酪氨酸磷酸化。通过渗透压应激刺激细胞可进一步增强这些磷酸化作用。Hic-5的Y60F突变体未被磷酸化，而在酪氨酸60位点磷酸化的Hic-5特异性结合Csk的SH2结构域。共表达实验表明，CAKβ对Hic-5的磷酸化需要CAKβ的激酶激活以及CAKβ与Hic-5的结合。CAKβ和Fyn对Hic-5的特异性磷酸化可能激活由Hic-5介导的信号通路。