真菌G蛋白信号调控蛋白的功能研究进展

Advances in functional research of RGS proteins in fungi

G蛋白信号途径是真菌细胞信号转导网络的枢纽,在细胞的各种生物学调控过程中具有重要作用。G蛋白信号调控蛋白(Rgulators of G protein signaling,RGS)是一类重要的G蛋白信号调控因子,能通过促进G蛋白α亚基(Gα)偶联的GTP水解,使Gα和Gβγ亚基发生聚合,导致G蛋白失活,从而迅速关闭与G蛋白偶联的信号途径。自从第一个RGS蛋白在酿酒酵母中被鉴定以来,目前已经有30多个RGS蛋白在重要的模式真菌中被报道,包括构巢曲霉、绿僵菌、稻瘟病菌、玉米赤霉菌、轮枝镰孢菌、新型隐球菌和白色念珠菌等。RGS蛋白在真菌的营养菌丝生长、产孢、毒素和色素生产、致病性和有性生殖等过程中发挥着重要作用。本文对真菌中已报道RGS蛋白的功能进行了总结,对真菌RGS蛋白的结构特征和调控机制进行了评述。

G protein is located in the hub of the cellular signal transduction network, important in regulating the activity of G-protein. Regulators of G protein signaling （RGS） primarily function as GTPase-accelerating proteins （GAPs） that promote GTP hydrolysis by the Gα subunits, thereby inactivating the G protein and rapidly switching off G protein-coupled signaling pathways. Since the first RGS protein was identified from the budding yeast Saccharomyces cerevisiae, more than 30 RGS proteins have been characterized from several typical fungi, such as Aspergillus nidulans, Metarhizium anisopliae, Magnaporthe oryzae, Gibberella zeae, Fusarium verticillioides, Cryptococcus neoformans and Candida albicans. RGS proteins play pivotal roles in fungi including vegetative growth, sporulation, mycotoxin/pigment production, pathogenicity and mating. In this review, the functions of RGS proteins in different fungi were summarized, and the functional domains and regulation mechanism of RGS proteins in fungi were discussed.