The Rtr1p CTD phosphatase autoregulates its mRNA through a degradation pathway involving the REX exonucleases
- 1Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, California 90095, USA
- 2Molecular Biology Institute, University of California, Los Angeles, Los Angeles, California 90095, USA
- Corresponding author: guillom{at}chem.ucla.edu
Abstract
Rtr1p is a phosphatase that impacts gene expression by modulating the phosphorylation status of the C-terminal domain of the large subunit of RNA polymerase II. Here, we show that Rtr1p is a component of a novel mRNA degradation pathway that promotes its autoregulation through turnover of its own mRNA. We show that the 3′UTR of the RTR1 mRNA contains a cis element that destabilizes this mRNA. RTR1 mRNA turnover is achieved through binding of Rtr1p to the RTR1 mRNP in a manner that is dependent on this cis element. Genetic evidence shows that Rtr1p-mediated decay of the RTR1 mRNA involves the 5′-3′ DExD/H-box RNA helicase Dhh1p and the 3′-5′ exonucleases Rex2p and Rex3p. Rtr1p and Rex3p are found associated with Dhh1p, suggesting a model for recruiting the REX exonucleases to the RTR1 mRNA for degradation. Rtr1p-mediated decay potentially impacts additional transcripts, including the unspliced BMH2 pre-mRNA. We propose that Rtr1p may imprint its RNA targets cotranscriptionally and determine their downstream degradation mechanism by directing these transcripts to a novel turnover pathway that involves Rtr1p, Dhh1p, and the REX family of exonucleases.
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Footnotes
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Article published online ahead of print. Article and publication date are at http://www.rnajournal.org/cgi/doi/10.1261/rna.055723.115.
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Freely available online through the RNA Open Access option.
- Received December 14, 2015.
- Accepted December 28, 2015.
This article, published in RNA, is available under a Creative Commons License (Attribution 4.0 International), as described at http://creativecommons.org/licenses/by/4.0/.