期刊名称:Proceedings of the National Academy of Sciences
印刷版ISSN:0027-8424
电子版ISSN:1091-6490
出版年度:2005
卷号:102
期号:14
页码:5002-5007
DOI:10.1073/pnas.0500543102
语种:English
出版社:The National Academy of Sciences of the United States of America
摘要:The 5' and 3' splice sites within an intron can, in principle, be joined to those within any other intron during pre-mRNA splicing. However, exons are joined in a strict 5' to 3' linear order in constitutively spliced pre-mRNAs. Thus, specific mechanisms must exist to prevent the random joining of exons. Here we report that insertion of exon sequences into an intron can inhibit splicing to the downstream 3' splice site and that this inhibition is independent of intron size. The exon sequences required for splicing inhibition were found to be exonic enhancer elements, and their inhibitory activity requires the binding of serine/arginine-rich splicing factors. We conclude that exonic enhancers can act as barriers to prevent exon skipping and thereby may play a key role in ensuring the correct 5' to 3' linear order of exons in spliced mRNA.
关键词:intronic splicing silencers ; pre-mRNA splicing ; accurate splice-site recognition and pairing