Zhang Guo-Wei, Song Huai-Dong, Chen Zhu
Shanghai Institute of Hematology, Ruijin Hospital, Shanghai 200025, China.
Yi Chuan Xue Bao. 2004 Jan;31(1):102-7.
Eukayotic pre-mRNAs are spliced to form mature mRNA. The pre-mRNAs alternative splicing greatly increases the diversity of proteins and the complexity of genes expression. The recognition of splice sites can occur across intron (intron definition) or across exon (exon definition). There are many kinds of alternative splicing patterns, including the choice of alternative splicing sites, the choice of alternative splicing ends, the alternative splicing of mutually exclusive exons, and an intron can be excised from or retained in mRNA. The splice sites choice process is regulated by many kinds of cis-acting and trans-acting elements and is closely related with the basic splicing process. Some of the splicing factors in basic splicing process can regulate the alternative splicing. The alternative splicing is also a co-transcriptional process. Promoters can regulate alternative splicing and produce different mRNA isoforms. Many molecular mechanisms of alternative splicing have been proposed, and it was also found that the RNA editing and trans-splicing could also regulate alternative splicing.
真核生物的前体信使核糖核酸（pre-mRNA）经过剪接形成成熟的信使核糖核酸（mRNA）。前体信使核糖核酸的可变剪接极大地增加了蛋白质的多样性和基因表达的复杂性。剪接位点的识别可以跨越内含子（内含子定义）或跨越外显子（外显子定义）。可变剪接有多种模式，包括可变剪接位点的选择、可变剪接末端的选择、互斥外显子的可变剪接，并且一个内含子可以从mRNA中切除或保留。剪接位点的选择过程受多种顺式作用元件和反式作用元件调控，且与基本剪接过程密切相关。基本剪接过程中的一些剪接因子可以调控可变剪接。可变剪接也是一个共转录过程。启动子可以调控可变剪接并产生不同的mRNA异构体。已经提出了许多可变剪接的分子机制，并且还发现RNA编辑和反式剪接也可以调控可变剪接。
