Kitazawa Masashi, Yamakuni Tohru, Song Si-Young, Kato Chieko, Tsuchiya Reiko, Ishida Mami, Suzuki Nobuhide, Adachi Eijiro, Iwashita Shintaro, Ueno Susumu, Yanagihara Nobuyuki, Taoka Masato, Isobe Toshiaki, Ohizumi Yasushi
Department of Pharmaceutical Molecular Biology, Graduate School of Pharmaceutical Sciences, Tohoku University, Aoba, Aramaki, Aoba-ku, Sendai 980-8578, Japan.
Biochem Biophys Res Commun. 2005 May 27;331(1):181-6. doi: 10.1016/j.bbrc.2005.03.127.
V-1, an ankyrin repeat protein with the activity to control tyrosine hydroxylase (TH) gene expression and transmitter release in PC12D cells, associates with CapZ, an actin capping protein, and thereby regulates actin polymerization in vitro. In this study, immunoprecipitation and Western blot analysis showed that V-1 was physically associated with CapZ-beta in PC12D transfectants overexpressing V-1. These proteins were co-localized in the soma of Purkinje cells of rat cerebellum as assayed by immunohistochemistry. Furthermore, in the V-1 transfectants, the amount of CapZ which physically associated with V-1 was steeply reduced at 2h after treatment with forskolin, but was thereafter increased to reach its initial level at 12h after forskolin-treatment. These results suggest that the association of V-1 with CapZ is controlled by a cAMP-dependent signalling pathway probably to play a functional role in the regulatory mechanism of actin dynamics in the endocrine system and the central nervous system.
V-1是一种具有控制PC12D细胞中酪氨酸羟化酶（TH）基因表达和递质释放活性的锚蛋白重复序列蛋白，它与肌动蛋白封端蛋白CapZ结合，从而在体外调节肌动蛋白聚合。在本研究中，免疫沉淀和蛋白质印迹分析表明，在过表达V-1的PC12D转染细胞中，V-1与CapZ-β在物理上相互关联。通过免疫组织化学分析，这些蛋白质在大鼠小脑浦肯野细胞的胞体中共定位。此外，在用福斯高林处理2小时后，在V-1转染细胞中，与V-1物理结合的CapZ量急剧减少，但在福斯高林处理12小时后又增加至初始水平。这些结果表明，V-1与CapZ的结合受cAMP依赖性信号通路的控制，可能在内分泌系统和中枢神经系统的肌动蛋白动力学调节机制中发挥功能作用。
