title: Prp5 bridges U1 and U2 snRNPs and enables stable U2 snRNP association with intron RNA.
abstract: Communication between U1 and U2 snRNPs is critical during pre-spliceosome assembly; yet, direct connections have not been observed. To investigate this assembly step, we focused on Prp5, an RNA-dependent ATPase of the DExD/H family. We identified homologs of Saccharomyces cerevisiae Prp5 in humans (hPrp5) and Schizosaccharomyces pombe (SpPrp5), and investigated their interactions and function. Depletion and reconstitution of SpPrp5 from extracts demonstrate that ATP binding and hydrolysis by Prp5 are required for pre-spliceosome complex A formation. hPrp5 and SpPrp5 are each physically associated with both U1 and U2 snRNPs; Prp5 contains distinct U1- and U2-interacting domains that are required for pre-spliceosome assembly; and, we observe a Prp5-associated U1/U2 complex in S. pombe. Together, these data are consistent with Prp5 being a bridge between U1 and U2 snRNPs at the time of pre-spliceosome formation.
authors.affiliation: Department of Cell Biology, Albert Einstein College of Medicine, Bronx, NY, USA.
authors.forename: Yong-Zhen
authors.initials: YZ
authors.lastname: Xu
authors.forename: Catherine M
authors.initials: CM
authors.lastname: Newnham
authors.forename: Sei
authors.initials: S
authors.lastname: Kameoka
authors.forename: Tao
authors.initials: T
authors.lastname: Huang
authors.forename: Maria M
authors.initials: MM
authors.lastname: Konarska
authors.forename: Charles C
authors.initials: CC
authors.lastname: Query
mesh_terms: D000251:Adenosine Triphosphatases / Q000737:chemistry / Q000378:metabolism / Q000502:physiology*; D000255:Adenosine Triphosphate / Q000378:metabolism; D053487:DEAD-box RNA Helicases; D005091:Exons; D007438:Introns; D008957:Models, Genetic; D017434:Protein Structure, Tertiary; D020365:RNA Helicases / Q000737:chemistry / Q000502:physiology*; D012322:RNA Precursors / Q000378:metabolism; D012333:RNA, Messenger / Q000737:chemistry / Q000378:metabolism*; D017412:Ribonucleoprotein, U1 Small Nuclear / Q000378:metabolism* / Q000502:physiology; D017413:Ribonucleoprotein, U2 Small Nuclear / Q000378:metabolism* / Q000502:physiology; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry; D012568:Schizosaccharomyces / Q000235:genetics / Q000378:metabolism; D029702:Schizosaccharomyces pombe Proteins / Q000737:chemistry / Q000502:physiology*; D017386:Sequence Homology, Amino Acid; D017381:Spliceosomes / Q000378:metabolism*
chemical_list: D012322:RNA Precursors; D012333:RNA, Messenger; D017412:Ribonucleoprotein, U1 Small Nuclear; D017413:Ribonucleoprotein, U2 Small Nuclear; D029701:Saccharomyces cerevisiae Proteins; D029702:Schizosaccharomyces pombe Proteins; D000255:Adenosine Triphosphate; D000251:Adenosine Triphosphatases; C467585:DDX46 protein, human; C064447:PRP5 protein, S cerevisiae; C488449:PRP5 protein, S pombe; D053487:DEAD-box RNA Helicases; D020365:RNA Helicases