Mutational analysis of the yeast RNA helicase Sub2p reveals conserved domains required for growth, mRNA export, and genomic stability
- Cyril Saguez1,3,
- Fernando A. Gonzales1,3,4,
- Manfred Schmid1,
- Andreas Bøggild1,
- Chrysa M. Latrick1,5,
- Francisco Malagon1,6,
- Andrea Putnam2,
- Lee Sanderson1,
- Eckhard Jankowsky2,
- Ditlev E. Brodersen1 and
- Torben Heick Jensen1,7
- 1Centre for mRNP Biogenesis and Metabolism, Department of Molecular Biology and Genetics, Aarhus University, 8000 Aarhus, Denmark
- 2Center for RNA Molecular Biology and Department of Biochemistry, School of Medicine, Case Western Reserve University, Cleveland, Ohio 44106, USA
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↵3 These authors contributed equally to this work.
Abstract
Sub2p/UAP56 is a highly conserved DEAD-box RNA helicase involved in the packaging and nuclear export of mRNA/protein particles (mRNPs). In Saccharomyces cerevisiae, Sub2p is recruited to active chromatin by the pentameric THO complex and incorporated into the larger transcription–export (TREX) complex. Sub2p also plays a role in the maintenance of genome integrity as its inactivation causes severe transcription-dependent recombination of DNA. Despite the central role of Sub2p in early mRNP biology, little is known about its function. Here, we report the presence of an N-terminal motif (NTM) conserved specifically in the Sub2p branch of RNA helicases. Mutation of the NTM causes nuclear accumulation of poly(A)+ RNA and impaired growth without affecting core helicase functions. Thus, the NTM functions as an autonomous unit. Moreover, two sub2 mutants, that are deficient in ATP binding, act in a trans-dominant negative fashion for growth and induce high recombination rates in vivo. Although wild-type Sub2p is prevented access to transcribed loci in such a background, this does not mechanistically explain the phenotype.
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↵7 Corresponding author
E-mail thj{at}mb.au.dk
- Received May 7, 2013.
- Accepted June 27, 2013.
- © 2013; Published by Cold Spring Harbor Laboratory Press for the RNA Society
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