The influence of microRNAs and poly(A) tail length on endogenous mRNA-protein complexes

• Main Authors: Wang, Miranda (Author), Lugowski, Andrew (Author), Nicholson, Beth (Author), Laver, John D. (Author), Sidhu, Sachdev S. (Author), Smibert, Craig A. (Author), Lipshitz, Howard D. (Author), Subtelny, Alexander Orest (Contributor), Rissland, Olivia S. (Contributor), Bartel, David (Contributor)
• Other Authors: Massachusetts Institute of Technology. Department of Biology (Contributor), Whitehead Institute for Biomedical Research (Contributor)
• Format: Article
• Language: English
• Published: Biomed Central Ltd., 2018-06-21T13:41:48Z.
• Subjects: Article
• Online Access: Get fulltext

Background: All mRNAs are bound in vivo by proteins to form mRNA-protein complexes (mRNPs), but changes in the composition of mRNPs during posttranscriptional regulation remain largely unexplored. Here, we have analyzed, on a transcriptome-wide scale, how microRNA-mediated repression modulates the associations of the core mRNP components eIF4E, eIF4G, and PABP and of the decay factor DDX6 in human cells. Results: Despite the transient nature of repressed intermediates, we detect significant changes in mRNP composition, marked by dissociation of eIF4G and PABP, and by recruitment of DDX6. Furthermore, although poly(A)-tail length has been considered critical in post-transcriptional regulation, differences in steady-state tail length explain little of the variation in either PABP association or mRNP organization more generally. Instead, relative occupancy of core components correlates best with gene expression. Conclusions: These results indicate that posttranscriptional regulatory factors, such as microRNAs, influence the associations of PABP and other core factors, and do so without substantially affecting steady-state tail length.
National Institutes of Health (U.S.) (Grant K99GM102319)
National Institutes of Health (U.S.) (Grant T32GM007753)
National Institutes of Health (U.S.) (Grant R01GM067031)
National Institutes of Health (U.S.) (Grant R35GM118135)
Natural Sciences and Engineering Research Council of Canada (Discovery Grant)