Mutational analysis of the yeast RNA helicase Sub2p reveals conserved domains required for growth, mRNA export, and genomic stability

RNA. 2013 Oct;19(10):1363-71. doi: 10.1261/rna.040048.113. Epub 2013 Aug 20.


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.

Keywords: RNA; RNA export; RNA helicase; genome stability.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenosine Triphosphatases / chemistry
  • Adenosine Triphosphatases / genetics*
  • Adenosine Triphosphatases / metabolism
  • Blotting, Western
  • Cell Nucleus / genetics
  • Chromatin / genetics
  • Chromatin Immunoprecipitation
  • Genomic Instability*
  • Mutation / genetics*
  • RNA Transport / genetics*
  • RNA, Fungal / genetics*
  • RNA, Messenger / genetics*
  • Saccharomyces cerevisiae / genetics*
  • Saccharomyces cerevisiae / growth & development
  • Saccharomyces cerevisiae / metabolism
  • Transcription, Genetic


  • Chromatin
  • RNA, Fungal
  • RNA, Messenger
  • Adenosine Triphosphatases
  • RNA-dependent ATPase