Remodeling of U2-U6 snRNA helix I during pre-mRNA splicing by Prp16 and the NineTeen Complex protein Cwc2.
Removal of intron regions from pre-messenger RNA (pre-mRNA) requires spliceosome assembly with pre-mRNA, then subsequent spliceosome remodeling to allow activation for the two steps of intron removal. Spliceosome remodeling is carried out through the action of DExD/H-box ATPases that modulate RNA-RNA and protein-RNA interactions. The ATPase Prp16 remodels the spliceosome between the first and second steps of splicing by catalyzing release of first step factors Yju2 and Cwc25 as well as destabilizing U2-U6 snRNA helix I. How Prp16 destabilizes U2-U6 helix I is not clear. We show that the NineTeen Complex (NTC) protein Cwc2 displays genetic interactions with the U6 ACAGAGA, the U6 internal stem loop (ISL) and the U2-U6 helix I, all RNA elements that form the spliceosome active site. We find that one function of Cwc2 is to stabilize U2-U6 snRNA helix I during splicing. Cwc2 also functionally cooperates with the NTC protein Isy1/NTC30. Mutation in Cwc2 can suppress the cold sensitive phenotype of the prp16-302 mutation indicating a functional link between Cwc2 and Prp16. Specifically the prp16-302 mutation in Prp16 stabilizes Cwc2 interactions with U6 snRNA and destabilizes Cwc2 interactions with pre-mRNA, indicating antagonistic functions of Cwc2 and Prp16. We propose that Cwc2 is a target for Prp16-mediated spliceosome remodeling during pre-mRNA splicing.
Faculty of Life Sciences, The University of Manchester, Oxford Road, Manchester, M13 9PT.
Rebecca
R
Hogg
Faculty of Life Sciences, The University of Manchester, Oxford Road, Manchester, M13 9PT.
Rogerio Alves
RA
de Almeida
Faculty of Life Sciences, The University of Manchester, Oxford Road, Manchester, M13 9PT.
Jayalath P D
JP
Ruckshanthi
Faculty of Life Sciences, The University of Manchester, Oxford Road, Manchester, M13 9PT rokeefe@manchester.ac.uk.
Raymond T
RT
O'Keefe
D000251:Adenosine Triphosphatases / Q000235:genetics*; D009154:Mutation; D009690:Nucleic Acid Conformation; D020365:RNA Helicases / Q000235:genetics*; D012322:RNA Precursors / Q000378:metabolism*; D012326:RNA Splicing; D000072260:RNA Splicing Factors; D012333:RNA, Messenger / Q000378:metabolism*; D012342:RNA, Small Nuclear / Q000737:chemistry* / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics* / Q000378:metabolism
C543031:Cwc2 protein, S cerevisiae; D012322:RNA Precursors; D000072260:RNA Splicing Factors; D012333:RNA, Messenger; D012342:RNA, Small Nuclear; D016601:RNA-Binding Proteins; D029701:Saccharomyces cerevisiae Proteins; C405484:U2 small nuclear RNA; C405486:U6 small nuclear RNA; D000251:Adenosine Triphosphatases; C075669:PRP16 protein, S cerevisiae; D020365:RNA Helicases