含B56调节亚基的PP2A全酶在肿瘤信号通路中的调控作用

Regulatory Function of B56-containing PP2A Holoenzyme in Cancer Signaling Pathways

蛋白磷酸酶2A（protein phosphatase 2A,PP2A）是细胞中广泛表达的异三聚体全酶,调节许多重要的信号通路,它的表达异常所致的信号通路紊乱会引发肿瘤和促进肿瘤的发展.PP2A在特定的状态下能够发挥抑癌因子的作用,这种抑癌特性由B调节亚基与底物的相互作用来决定,因此B调节亚基在PP2A的抑癌功能中起关键作用.

Protein phosphatase 2A （PP2A） is a widely expressed cell heterotrimeric holoenzyme. It functions in regulation of many important cell signaling pathways. Disorders in signaling pathways caused by PP2A abnormal expression contribute to tumor initiation and progression. Many studies have showed that PP2A plays a role as a tumor suppressor under specific conditions. However, the tumor suppressing activity of PP2A is determined by the interaction of its B regulatory subunit with its substrate. Therefore, B regulatory subunit is critical to PP2A＇s tumor suppressing function. In this review, we summarize the structure and physiological functions of PP2A regulatory subunit B56, specifically the regulatory roles of PP2A holoenzyme containing regulatory subunit B56 in several major cancer signaling pathways, and explain the relationship between PP2As containing specific regulatory subunit with diseases.