剪接因子U2AF65相关蛋白的研究进展

U2核糖核蛋白小体辅助因子(U2AF)65是参与前体mRNA剪接的重要辅助因子,前体RNA生成之初,U1核糖核蛋白小体(snRNP)结合到内含子的5'剪接位点,U2AF65和U2AF35分别结合到多聚嘧啶序列和3'剪接位点,剪接因子1(SF1)结合到分支位点是剪接体形成的第一步。U2AF的存在又辅助U2snRNP代替SF1结合到分支位点,使剪接反应顺利进行。最近几年,发现基因组中存在一些U2AF65的旁系同源基因序列。这些旁系同源基因由祖先基因经连续复制而横向形成,复制出的基因副本经历了各自的进化途径,最终它们在结构和功能上有相似之处,又各有独特之处。我们简要讨论了U2AF65、PUF60、CAPERα和CAPERβ这4种同源蛋白的发现过程、结构特征、自身的多样性、基因的进化和生物学功能。

Progress of the Study of U2AF65 Splicing Factor Related Proteins

U2 small nuclear ribonucleoprotein（snRNP） auxiliary factor 65kD（U2AF65） is an essential splicing fac-tor（SF） in pre-mRNA splicing.Recognition of 5＇ splice site by U1snRNP,binding of U2AF65 to the polypyrimidine（Py-tract） and U2AF35 to 3＇ splice site,and binding of SF1 to branch site bring about the assembly of splicing commitment complex.Then with the auxiliary of U2AF,U2snRNP replaces SF1 at the branch site so as to make sure the splicing reaction go well on.During the past few years,several paralogs for U2AF65 have been discov-ered.They derive from a single ancestral gene duplicated within a genome and then experience different ways to evolve.These proteins have similarities and differences in structure and function.Here,we reviewed the discovery of each protein,the conserved structural features that characterize the U2AF65 related proteins,the diversity of each protein and evolution situation of these genes.And we discussed the biological functions of these proteins.