Splice site strength–dependent activity and genetic buffering by poly-G runs

Pre-mRNA splicing is regulated through the combinatorial activity of RNA motifs, including splice sites and splicing regulatory elements. Here we show that the activity of the G-run (polyguanine sequence) class of splicing enhancer elements is approx4-fold higher when adjacent to intermediate streng...

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Bibliographic Details
Main Authors: Xiao, Xinshu, Wang, Zefeng, Jang, Minyoung, Nutiu, Razvan, Wang, Eric T, Burge, Christopher B
Other Authors: Whitaker College of Health Sciences and Technology
Format: Article
Language:en_US
Published: Nature Publishing Group 2011
Online Access:http://hdl.handle.net/1721.1/66571
https://orcid.org/0000-0002-6605-3637
Description
Summary:Pre-mRNA splicing is regulated through the combinatorial activity of RNA motifs, including splice sites and splicing regulatory elements. Here we show that the activity of the G-run (polyguanine sequence) class of splicing enhancer elements is approx4-fold higher when adjacent to intermediate strength 5' splice sites (ss) than when adjacent to weak 5' ss, and approx1.3-fold higher relative to strong 5' ss. We observed this dependence on 5' ss strength in both splicing reporters and in global microarray and mRNA-Seq analyses of splicing changes following RNA interference against heterogeneous nuclear ribonucleoprotein (hnRNP) H, which cross-linked to G-runs adjacent to many regulated exons. An exon's responsiveness to changes in hnRNP H levels therefore depends in a complex way on G-run abundance and 5' ss strength. This pattern of activity enables G-runs and hnRNP H to buffer the effects of 5' ss mutations, augmenting both the frequency of 5' ss polymorphism and the evolution of new splicing patterns. Certain other splicing factors may function similarly.