McKenzie Jenny A G, Riento Kirsi, Ridley Anne J
Ludwig Institute for Cancer Research, Royal Free and University College, School of Medicine, 91 Riding Street, London WIW 7BS, UK.
FEBS Lett. 2006 Apr 17;580(9):2388-94. doi: 10.1016/j.febslet.2006.03.048.
Occludin is an integral-membrane protein that contributes to tight junction function. We have identified casein kinase I epsilon (CKI epsilon) as a binding partner for the C-terminal cytoplasmic domain of occludin by yeast two-hybrid screening. CKI epsilon phosphorylated occludin and co-localised and co-immunoprecipitated with occludin from human endothelial cells. Amino acids 265-318 of occludin were sufficient for CKI epsilon binding and phosphorylation. Deletion of the C-terminal 48 amino acids of occludin increased CKI epsilon binding and phosphorylation, suggesting that this region inhibits CKI epsilon binding. These data identify CKI epsilon as a novel occludin kinase that may be important for the regulation of occludin.
闭合蛋白是一种有助于紧密连接功能的整合膜蛋白。我们通过酵母双杂交筛选，确定酪蛋白激酶Iε（CKIε）为闭合蛋白C端胞质结构域的结合伴侣。CKIε使闭合蛋白磷酸化，并与人内皮细胞中的闭合蛋白共定位和共免疫沉淀。闭合蛋白的第265 - 318位氨基酸足以实现CKIε的结合和磷酸化。缺失闭合蛋白C端的48个氨基酸会增加CKIε的结合和磷酸化，表明该区域抑制CKIε的结合。这些数据确定CKIε为一种新型的闭合蛋白激酶，可能对闭合蛋白的调节很重要。
