Please use this identifier to cite or link to this item:
Title: Regulation of mRNA abundance by polypyrimidine tract-binding protein-controlled alternate 5′ splice site choice
Authors: Hamid, Fursham M.
Makeyev, Eugene V.
Keywords: DRNTU::Science::Biological sciences
Issue Date: 2014
Source: Hamid, F. M., & Makeyev, E. V. (2014). Regulation of mRNA abundance by polypyrimidine tract-binding protein-controlled alternate 5′ splice site choice. PLoS genetics, 10(11), e1004771-.
Series/Report no.: PLoS genetics
Abstract: Alternative splicing (AS) provides a potent mechanism for increasing protein diversity and modulating gene expression levels. How alternate splice sites are selected by the splicing machinery and how AS is integrated into gene regulation networks remain important questions of eukaryotic biology. Here we report that polypyrimidine tract-binding protein 1 (Ptbp1/PTB/hnRNP-I) controls alternate 5′ and 3′ splice site (5′ss and 3′ss) usage in a large set of mammalian transcripts. A top scoring event identified by our analysis was the choice between competing upstream and downstream 5′ss (u5′ss and d5′ss) in the exon 18 of the Hps1 gene. Hps1 is essential for proper biogenesis of lysosome-related organelles and loss of its function leads to a disease called type 1 Hermansky-Pudlak Syndrome (HPS). We show that Ptbp1 promotes preferential utilization of the u5′ss giving rise to stable mRNAs encoding a full-length Hps1 protein, whereas bias towards d5′ss triggered by Ptbp1 down-regulation generates transcripts susceptible to nonsense-mediated decay (NMD). We further demonstrate that Ptbp1 binds to pyrimidine-rich sequences between the u5′ss and d5′ss and activates the former site rather than repressing the latter. Consistent with this mechanism, u5′ss is intrinsically weaker than d5′ss, with a similar tendency observed for other genes with Ptbp1-induced u5′ss bias. Interestingly, the brain-enriched Ptbp1 paralog Ptbp2/nPTB/brPTB stimulated the u5′ss utilization but with a considerably lower efficiency than Ptbp1. This may account for the tight correlation between Hps1 with Ptbp1 expression levels observed across mammalian tissues. More generally, these data expand our understanding of AS regulation and uncover a post-transcriptional strategy ensuring co-expression of a subordinate gene with its master regulator through an AS-NMD tracking mechanism.
ISSN: 1553-7404
DOI: 10.1371/journal.pgen.1004771
Rights: © 2014 Hamid, Makeyev. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Fulltext Permission: open
Fulltext Availability: With Fulltext
Appears in Collections:SBS Journal Articles

Google ScholarTM




Items in DR-NTU are protected by copyright, with all rights reserved, unless otherwise indicated.