Balda M S, Anderson J M, Matter K
Department of Cell Biology, Science III, University of Geneva, Switzerland.
FEBS Lett. 1996 Dec 16;399(3):326-32. doi: 10.1016/s0014-5793(96)01352-x.
ZO-1 is a tight junction phosphoprotein partially homologous to a tumor suppressor in Drosophila. The homologous region contains an SH3 domain with an unidentified function. Using fusion proteins containing the SH3 domain and various N- and C-terminal sequences, we tested for association of a kinase with this protein domain in extracts of MDCK cells. We show that the SH3 domain of ZO-1 binds a serine protein kinase that phosphorylates a region immediately C-terminal to the SH3 domain. This kinase associates specifically with the SH3 domain of ZO-1 and appears to be also associated with junctional complexes extracted from MDCK cells.
紧密连接蛋白1（ZO-1）是一种紧密连接磷蛋白，与果蝇中的一种肿瘤抑制因子部分同源。同源区域包含一个功能未知的SH3结构域。我们使用含有SH3结构域以及各种N端和C端序列的融合蛋白，在MDCK细胞提取物中检测一种激酶与该蛋白结构域的结合情况。我们发现，ZO-1的SH3结构域结合一种丝氨酸蛋白激酶，该激酶使SH3结构域紧邻的C端区域发生磷酸化。这种激酶特异性地与ZO-1的SH3结构域结合，并且似乎也与从MDCK细胞中提取的连接复合体相关。
