A defect of Kap104 alleviates the requirement of mitotic exit network gene functions in Saccharomyces cerevisiae.
A subgroup of the karyopherin beta (also called importin beta) protein that includes budding yeast Kap104 and human transportin/karyopherin beta2 is reported to function as a receptor for the transport of mRNA-binding proteins into the nucleus. We identified KAP104 as a responsible gene for a suppressor mutation of cdc15-2. We found that the kap104-E604K mutation suppressed the temperature-sensitive growth of cdc15-2 cells by promoting the exit from mitosis and suppressed the temperature sensitivity of various mitotic-exit mutations. The cytokinesis defect of these mitotic-exit mutants was not suppressed by kap104-E604K. Furthermore, the kap104-E604K mutation delays entry into DNA synthesis even at a permissive temperature. In cdc15-2 kap104-E604K cells, SWI5 and SIC1, but not CDH1, became essential at a high temperature, suggesting that the kap104-E604K mutation promotes mitotic exit via the Swi5-Sic1 pathway. Interestingly, SPO12, which is involved in the release of Cdc14 from the nucleolus during early anaphase, also became essential in cdc15-2 kap104-E604K cells at a high temperature. The kap104-E604K mutation caused a partial delocalization of Cdc14 from the nucleolus during interphase. This delocalization of Cdc14 was suppressed by the deletion of SPO12. These results suggest that a mutation in Kap104 stimulates exit from mitosis through the activation of Cdc14 and implies a novel role for Kap104 in cell-cycle progression in budding yeast.
Asakawa
Kazuhide
K
Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Hongo, Tokyo 113-0033, Japan.
Toh-e
Akio
A
D001483:Base Sequence; D002453:Cell Cycle / Q000235:genetics; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism; D002455:Cell Division / Q000235:genetics; D002466:Cell Nucleolus / Q000378:metabolism; D050756:Cyclin-Dependent Kinase Inhibitor Proteins; D004271:DNA, Fungal / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism; D005800:Genes, Fungal; D006801:Humans; D007399:Interphase / Q000235:genetics; D028884:Karyopherins / Q000235:genetics* / Q000378:metabolism; D008938:Mitosis / Q000235:genetics; D009154:Mutation; D009687:Nuclear Proteins; D017027:Protein Tyrosine Phosphatases / Q000235:genetics / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000166:cytology* / Q000235:genetics* / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics* / Q000378:metabolism; D013489:Suppression, Genetic; D013696:Temperature; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D028961:beta Karyopherins
C074860:CDC14 protein, S cerevisiae; D018797:Cell Cycle Proteins; D050756:Cyclin-Dependent Kinase Inhibitor Proteins; D004271:DNA, Fungal; D004268:DNA-Binding Proteins; D005656:Fungal Proteins; C101820:KAP104 protein, S cerevisiae; D028884:Karyopherins; D009687:Nuclear Proteins; C086926:SIC1 protein, S cerevisiae; C416648:SPO12 protein, S cerevisiae; C080218:SWI5 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; D028961:beta Karyopherins; D017027:Protein Tyrosine Phosphatases