Extensive genetic interactions between PRP8 and PRP17/CDC40, two yeast genes involved in pre-mRNA splicing and cell cycle progression.
Biochemical and genetic experiments have shown that the PRP17 gene of the yeast Saccharomyces cerevisiae encodes a protein that plays a role during the second catalytic step of the splicing reaction. It was found recently that PRP17 is identical to the cell division cycle CDC40 gene. cdc40 mutants arrest at the restrictive temperature after the completion of DNA replication. Although the PRP17/CDC40 gene product is essential only at elevated temperatures, splicing intermediates accumulate in prp17 mutants even at the permissive temperature. In this report we describe extensive genetic interactions between PRP17/CDC40 and the PRP8 gene. PRP8 encodes a highly conserved U5 snRNP protein required for spliceosome assembly and for both catalytic steps of the splicing reaction. We show that mutations in the PRP8 gene are able to suppress the temperature-sensitive growth phenotype and the splicing defect conferred by the absence of the Prp17 protein. In addition, these mutations are capable of suppressing certain alterations in the conserved PyAG trinucleotide at the 3' splice junction, as detected by an ACT1-CUP1 splicing reporter system. Moreover, other PRP8 alleles exhibit synthetic lethality with the absence of Prp17p and show a reduced ability to splice an intron bearing an altered 3' splice junction. On the basis of these findings, we propose a model for the mode of interaction between the Prp8 and Prp17 proteins during the second catalytic step of the splicing reaction.
Ben-Yehuda
S
S
Department of Molecular Microbiology and Biotechnology, Tel Aviv University, Ramat Aviv 69978, Israel.
Russell
C S
CS
Dix
I
I
Beggs
J D
JD
Kupiec
M
M
D000483:Alleles; D001483:Base Sequence; D002453:Cell Cycle / Q000235:genetics*; D018797:Cell Cycle Proteins / Q000235:genetics; D004268:DNA-Binding Proteins; D004303:Dosage Compensation, Genetic; D005656:Fungal Proteins / Q000235:genetics; D005800:Genes, Fungal; D016296:Mutagenesis; D010641:Phenotype; D012313:RNA; D012322:RNA Precursors / Q000235:genetics*; D012326:RNA Splicing; D000072260:RNA Splicing Factors; D012333:RNA, Messenger / Q000235:genetics*; D016601:RNA-Binding Proteins; D017414:Ribonucleoprotein, U4-U6 Small Nuclear; D017415:Ribonucleoprotein, U5 Small Nuclear; D012441:Saccharomyces cerevisiae / Q000235:genetics; D029701:Saccharomyces cerevisiae Proteins
C093570:CDC40 protein, S cerevisiae; D018797:Cell Cycle Proteins; D004268:DNA-Binding Proteins; D005656:Fungal Proteins; C077018:PRP8 protein, S cerevisiae; D012322:RNA Precursors; D000072260:RNA Splicing Factors; C034477:RNA primers; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; D017414:Ribonucleoprotein, U4-U6 Small Nuclear; D017415:Ribonucleoprotein, U5 Small Nuclear; D029701:Saccharomyces cerevisiae Proteins; D012313:RNA