The SF3b complex is an intrinsic component of the functional U2 small nuclear ribonucleoprotein (snRNP). As U2 snRNP enters nuclear pre-mRNA splicing, SF3b plays key roles in recognizing the branch point sequence (BPS) and facilitating spliceosome assembly and activation. Since the discovery of SF3b, substantial progress has been made in elucidating its molecular mechanism during splicing. In addition, numerous recent studies indicate that SF3b and its components are engaged in various molecular and cellular events that are beyond the canonical role in splicing. This review summarizes the current knowledge on the SF3b complex and highlights its multiple roles in splicing and beyond.

SF3b复合体是功能性U2小核糖核糖核蛋白（snRNP）的固有组成部分。当U2 snRNP进入核mRNA前体剪接时，SF3b在识别分支点序列（BPS）和促进剪接体组装和激活中起关键作用。自发现SF3b以来，在阐明剪接过程中的分子机制方面已取得了实质性进展。另外，最近的大量研究表明，SF3b及其组分参与了各种分子和细胞事件，而这些事件在剪接中都没有规范作用。这篇综述总结了关于SF3b复合体的当前知识，并着重介绍了其在剪接及以后的多重作用。