G蛋白偶联受体激酶和arrestins在受体调节中的作用

Effect of receptor kinases & arrestins in G protein coupled receptor regulation

Ｇ 蛋白偶联受体（ Ｇｐｒｏｔｅｉｎｃｏｕｐｌｅｄ ｒｅｃｅｐｔｏｒ ， Ｇ Ｐ Ｃ Ｒｓ）是一大家族，介导许多激素的信号转导。在激动剂的持续作用下， Ｇ Ｐ Ｃ Ｒｓ 可发生对激动剂的敏感性下降，即受体减敏，现认为这一过程主要由 Ｇ 蛋白偶联受体激酶（ Ｇｐｒｏｔｅｉｎｃｏｕｐｌｅｄ ｒｅｃｅｐｔｏｒ ｋｉｎａｓｅｓ ， Ｇ Ｒ Ｋｓ） 和ａｒｒｅｓｔｉｎｓ 两大蛋白家族介导： Ｇ Ｒ Ｋｓ 先结合并磷酸化被激动剂占领的受体，然后ａｒｒｅｓｔｉｎｓ与磷酸化的受体结合，阻止受体与 Ｇ 蛋白发生作用，导致受体功能减退。近来发现， Ｇ Ｒ Ｋｓ 和ａｒｒｅｓｔｉｎｓ 还参与受体的内陷机制。

G protein coupled receptors (GPCRs) mediate many signal transduction pathways. Most GPCRs are often desensitized during agonist exposure. The process appears to be mainly mediated by G protein coupled receptor kinases (GRKs) and arrestins: GRKs bind to agonist occupied receptors and phosphorylate them, which leads to the binding of arrestin and prevents the interaction of receptor and G protein. Recent studies have revealed that GRKs and arrestins also play important roles in endocytosis of GPCRs related to receptor resensitization.