Genetic interactions with CLF1 identify additional pre-mRNA splicing factors and a link between activators of yeast vesicular transport and splicing.
Clf1 is a conserved spliceosome assembly factor composed predominately of TPR repeats. Here we show that the TPR elements are not functionally equivalent, with the amino terminus of Clf1 being especially sensitive to change. Deletion and add-back experiments reveal that the splicing defect associated with TPR removal results from the loss of TPR-specific sequence information. Twelve mutants were found that show synthetic growth defects when combined with an allele that lacks TPR2 (i.e., clf1Delta2). The identified genes encode the Mud2, Ntc20, Prp16, Prp17, Prp19, Prp22, and Syf2 splicing factors and four proteins without established contribution to splicing (Bud13, Cet1, Cwc2, and Rds3). Each synthetic lethal with clf1Delta2 (slc) mutant is splicing defective in a wild-type CLF1 background. In addition to the splicing factors, SSD1, BTS1, and BET4 were identified as dosage suppressors of clf1Delta2 or selected slc mutants. These results support Clf1 function through multiple stages of the spliceosome cycle, identify additional genes that promote cellular mRNA maturation, and reveal a link between Rab/Ras GTPase activation and the process of pre-mRNA splicing.
Vincent
Kevin
K
Department of Biology, University of Kentucky, Lexington, Kentucky 40506-0225, USA.
Wang
Qiang
Q
Jay
Steven
S
Hobbs
Kathryn
K
Rymond
Brian C
BC
D000483:Alleles; D000595:Amino Acid Sequence; D015152:Blotting, Northern; D017353:Gene Deletion; D008969:Molecular Sequence Data; D009841:Oligonucleotides; D017434:Protein Structure, Tertiary; D012326:RNA Splicing / Q000235:genetics*; D012333:RNA, Messenger / Q000235:genetics; D016601:RNA-Binding Proteins / Q000235:genetics*; D016415:Sequence Alignment; D017381:Spliceosomes / Q000235:genetics / Q000502:physiology*; D022161:Transport Vesicles / Q000235:genetics / Q000502:physiology*; D015003:Yeasts; D020691:rab GTP-Binding Proteins
D009841:Oligonucleotides; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; D020691:rab GTP-Binding Proteins