Hosking Catherine Rose, Ulloa Fausto, Hogan Catherine, Ferber Emma C, Figueroa Angélica, Gevaert Kris, Birchmeier Walter, Briscoe James, Fujita Yasuyuki
Medical Research Council Laboratory for Molecular Cell Biology and Cell Biology Unit, Department of Biology, University College London, London WC1E 6BT, UK.
Mol Biol Cell. 2007 May;18(5):1918-27. doi: 10.1091/mbc.e06-10-0941. Epub 2007 Mar 7.
In epithelial cells, p120 catenin (p120) localizes at cell-cell contacts and regulates adhesive function of the cadherin complex. In addition, p120 has been reported to localize in the nucleus, although the nuclear function of p120 is not fully understood. Here, we report the identification of Gli-similar 2 (Glis2) as a novel binding protein for p120. Glis2 is a Krüppel-like transcriptional repressor with homology to the Gli family, but its physiological function has not been well characterized. In this study, we show that coexpression of Glis2 and Src induces nuclear translocation of p120. Furthermore, p120 induces the C-terminal cleavage of Glis2, and this cleavage is further enhanced by Src. The cleaved form of Glis2 loses one of its five zinc finger domains, but it is still able to bind DNA. Functional studies in chick neural tube indicate that full-length Glis2 can affect neuronal differentiation, whereas the cleaved form requires coexpression of p120 to have a similar effect. These data indicate that p120 has additional novel functions in the nucleus together with Glis2.
在上皮细胞中,p120连环蛋白(p120)定位于细胞间连接并调节钙黏蛋白复合体的黏附功能。此外,据报道p120也定位于细胞核,尽管其核功能尚未完全明确。在此,我们报告鉴定出Gli相似蛋白2(Glis2)是p120的一种新型结合蛋白。Glis2是一种与Gli家族具有同源性的类Krüppel转录抑制因子,但其生理功能尚未得到充分表征。在本研究中,我们表明Glis2和Src的共表达诱导p120的核转位。此外,p120诱导Glis2的C末端裂解,并且Src进一步增强这种裂解。裂解形式的Glis2失去其五个锌指结构域之一,但它仍然能够结合DNA。在鸡神经管中的功能研究表明,全长Glis2可以影响神经元分化,而裂解形式需要与p120共表达才能产生类似的效果。这些数据表明,p120与Glis2在细胞核中具有额外的新功能。