The identification and characterization of a novel splicing protein, Isy1p, of Saccharomyces cerevisiae.
We have identified a novel splicing factor, Isy1p, through two-hybrid screens for interacting proteins involved in nuclear pre-mRNA splicing. Isy1p was tagged and demonstrated to be part of the splicing machinery, associated with spliceosomes throughout the splicing reactions. At least a portion of the Isy1 protein population is associated with snRNAs; low levels of U5 and U6 snRNAs are coimmunoprecipitated specifically with Isy1p. When the ISY1 gene was knocked out, no defect in vegetative growth was observed. Using a sensitive in vivo splicing assay, however, we observed lower splicing efficiency in the isy1 null mutant compared to wild-type, indicating that Isy1 p is important in the optimization of splicing.
Dix
I
I
Institute of Cell and Molecular Biology, University of Edinburgh, United Kingdom.
Russell
C
C
Yehuda
S B
SB
Kupiec
M
M
Beggs
J D
JD
D000595:Amino Acid Sequence; D003001:Cloning, Molecular; D005656:Fungal Proteins / Q000737:chemistry / Q000235:genetics; D017353:Gene Deletion; D017930:Genes, Reporter / Q000235:genetics; D008969:Molecular Sequence Data; D009154:Mutation; D009687:Nuclear Proteins / Q000737:chemistry / Q000235:genetics; D011233:Precipitin Tests; D012322:RNA Precursors / Q000235:genetics; D012326:RNA Splicing / Q000235:genetics*; D012333:RNA, Messenger / Q000032:analysis; D016601:RNA-Binding Proteins / Q000737:chemistry / Q000235:genetics*; D017411:Ribonucleoproteins, Small Nuclear / Q000235:genetics; D012441:Saccharomyces cerevisiae / Q000235:genetics*; D029701:Saccharomyces cerevisiae Proteins; D016415:Sequence Alignment; D017381:Spliceosomes / Q000235:genetics
D005656:Fungal Proteins; C118319:ISY1 protein, S cerevisiae; D009687:Nuclear Proteins; D012322:RNA Precursors; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; D017411:Ribonucleoproteins, Small Nuclear; D029701:Saccharomyces cerevisiae Proteins