Crm1-mediated nuclear export of Cdc14 is required for the completion of cytokinesis in budding yeast.
The mitotic exit network (MEN) controls the exit from mitosis in budding yeast. The proline-directed phosphatase, Cdc14p, is a key component of MEN and promotes mitotic exit by activating the degradation of Clb2p and by reversing Cdk-mediated mitotic phosphorylation. Cdc14p is sequestered in the nucleolus during much of the cell cycle and is released in anaphase from the nucleolus to the nucleoplasm and cytoplasm to perform its functions. Release of Cdc14p from the nucleolus during anaphase is well understood. In contrast, less is known about the mechanism by which Cdc14p is released from the nucleus to the cytoplasm. Here we show that Cdc14p contains a leucine-rich nuclear export signal (NES) that interacts with Crm1p physically. Mutations in the NES of Cdc14p allow Clb2p degradation and mitotic exit, but cause abnormal morphology and cytokinesis defects at non-permissive temperatures. Cdc14p localizes to the bud neck, among other cytoplasmic structures, following its release from the nucleolus in late anaphase. This bud neck localization of Cdc14p is disrupted by mutations in its NES and by the leptomycin B-mediated inhibition of Crm1p. Our results suggest a requirement for Crm1p-dependent nuclear export of Cdc14p in coordinating mitotic exit and cytokinesis in budding yeast.
Bembenek
Joshua
J
Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA.
Kang
Jungseog
J
Kurischko
Cornelia
C
Li
Bing
B
Raab
Jesse R
JR
Belanger
Kenneth D
KD
Luca
Francis C
FC
Yu
Hongtao
H
D021581:Active Transport, Cell Nucleus; D000595:Amino Acid Sequence; D000818:Animals; D018797:Cell Cycle Proteins / Q000737:chemistry / Q000378:metabolism*; D002467:Cell Nucleus / Q000378:metabolism*; D002478:Cells, Cultured; D019926:Cyclin B / Q000378:metabolism; D048749:Cytokinesis; D054637:Dual-Specificity Phosphatases; D005231:Fatty Acids, Unsaturated / Q000494:pharmacology; D006801:Humans; D028884:Karyopherins / Q000378:metabolism*; D051379:Mice; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D049790:Nuclear Export Signals; D010641:Phenotype; D010744:Phosphoric Monoester Hydrolases / Q000737:chemistry / Q000378:metabolism; D021381:Protein Transport; D017027:Protein Tyrosine Phosphatases / Q000737:chemistry / Q000378:metabolism*; D018160:Receptors, Cytoplasmic and Nuclear / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry / Q000378:metabolism*; D004718:Saccharomycetales / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism*; D016415:Sequence Alignment; D000097606:Exportin 1 Protein
D018797:Cell Cycle Proteins; D019926:Cyclin B; D054637:Dual-Specificity Phosphatases; D005231:Fatty Acids, Unsaturated; D028884:Karyopherins; D049790:Nuclear Export Signals; D010744:Phosphoric Monoester Hydrolases; D017027:Protein Tyrosine Phosphatases; D018160:Receptors, Cytoplasmic and Nuclear; D029701:Saccharomyces cerevisiae Proteins; D000097606:Exportin 1 Protein; C074860:CDC14 protein, S cerevisiae; C093749:CLB2 protein, S cerevisiae; C120902:CDC14A protein, human; C474200:CDC14B protein, human; C038753:leptomycin B