title: Spliceosomal DEAH-Box ATPases Remodel Pre-mRNA to Activate Alternative Splice Sites.
abstract: During pre-mRNA splicing, a central step in the expression and regulation of eukaryotic genes, the spliceosome selects splice sites for intron excision and exon ligation. In doing so, the spliceosome must distinguish optimal from suboptimal splice sites. At the catalytic stage of splicing, suboptimal splice sites are repressed by the DEAH-box ATPases Prp16 and Prp22. Here, using budding yeast, we show that these ATPases function further by enabling the spliceosome to search for and utilize alternative branch sites and 3' splice sites. The ATPases facilitate this search by remodeling the splicing substrate to disengage candidate splice sites. Our data support a mechanism involving 3' to 5' translocation of the ATPases along substrate RNA and toward a candidate site, but, surprisingly, not across the site. Thus, our data implicate DEAH-box ATPases in acting at a distance by pulling substrate RNA from the catalytic core of the spliceosome.
authors.affiliation: Graduate Program in Cell and Molecular Biology, University of Chicago, 920 East 58(th) Street, Chicago, IL 60637, USA.
authors.forename: Daniel R
authors.initials: DR
authors.lastname: Semlow
authors.affiliation: Cellular and Molecular Biology, University of Michigan, 930 North University Avenue, Ann Arbor, MI 48109, USA; Single Molecule Analysis Group, Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, MI 48109, USA.
authors.forename: Mario R
authors.initials: MR
authors.lastname: Blanco
authors.affiliation: Single Molecule Analysis Group, Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, MI 48109, USA.
authors.forename: Nils G
authors.initials: NG
authors.lastname: Walter
authors.affiliation: Department of Molecular Genetics and Cell Biology, University of Chicago, 920 East 58(th) Street, Chicago, IL 60637, USA. Electronic address: jstaley@uchicago.edu.
authors.forename: Jonathan P
authors.initials: JP
authors.lastname: Staley
mesh_terms: D000251:Adenosine Triphosphatases / Q000378:metabolism*; D053487:DEAD-box RNA Helicases / Q000378:metabolism*; D005091:Exons; D020365:RNA Helicases / Q000378:metabolism*; D012322:RNA Precursors / Q000235:genetics / Q000378:metabolism; D022821:RNA Splice Sites; D000072260:RNA Splicing Factors; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism*; D017381:Spliceosomes / Q000378:metabolism*
chemical_list: D012322:RNA Precursors; D022821:RNA Splice Sites; D000072260:RNA Splicing Factors; D029701:Saccharomyces cerevisiae Proteins; D000251:Adenosine Triphosphatases; C075669:PRP16 protein, S cerevisiae; C067135:PRP22 protein, S cerevisiae; D053487:DEAD-box RNA Helicases; D020365:RNA Helicases