Watanabe G, Saito Y, Madaule P, Ishizaki T, Fujisawa K, Morii N, Mukai H, Ono Y, Kakizuka A, Narumiya S
Department of Pharmacology, Kyoto University Faculty of Medicine, Japan.
Science. 1996 Feb 2;271(5249):645-8. doi: 10.1126/science.271.5249.645.
The Rho guanosine 5'-triphosphatase (GTPase) cycles between the active guanosine triphosphate (GTP)-bound form and the inactive guanosine diphosphate-bound form and regulates cell adhesion and cytokinesis, but how it exerts these actions is unknown. The yeast two-hybrid system was used to clone a complementary DNA for a protein (designated Rhophilin) that specifically bound to GTP-Rho. The Rho-binding domain of this protein has 40 percent identity with a putative regulatory domain of a protein kinase, PKN. PKN itself bound to GTP-Rho and was activated by this binding both in vitro and in vivo. This study indicates that a serine-threonine protein kinase is a Rho effector and presents an amino acid sequence motif for binding to GTP-Rho that may be shared by a family of Rho target proteins.
Rho鸟苷5'-三磷酸酶（GTP酶）在活性鸟苷三磷酸（GTP）结合形式和非活性鸟苷二磷酸结合形式之间循环，并调节细胞黏附和胞质分裂，但它如何发挥这些作用尚不清楚。利用酵母双杂交系统克隆了一种与GTP-Rho特异性结合的蛋白质（命名为Rhophilin）的互补DNA。该蛋白质的Rho结合结构域与一种蛋白激酶PKN的假定调节结构域有40%的同源性。PKN自身与GTP-Rho结合，并在体外和体内被这种结合激活。这项研究表明，一种丝氨酸-苏氨酸蛋白激酶是Rho效应器，并呈现出一个可能为Rho靶蛋白家族所共有的与GTP-Rho结合的氨基酸序列基序。
