Saccharomyces cerevisiae Mob1p is required for cytokinesis and mitotic exit

F. C. Luca, M. Mody, C. Kurischko, D. M. Roof, T. H. Giddings, Mark Winey

Research output: Contribution to journalArticle

112 Citations (Scopus)

Abstract

The Saccharomyces cerevisiae mitotic exit network (MEN) is a conserved set of genes that mediate the transition from mitosis to G1 by regulating mitotic cyclin degradation and the inactivation of cyclin-dependent kinase (CDK). Here, we demonstrate that, in addition to mitotic exit, S. cerevisiae MEN gene MOB1 is required for cytokinesis and cell separation. The cytokinesis defect was evident in mob1 mutants under conditions in which there was no mitotic-exit defect. Observation of live cells showed that yeast myosin II, Myo1p, was present in the contractile ring at the bud neck but that the ring failed to contract and disassemble. The cytokinesis defect persisted for several mitotic cycles, resulting in chains of cells with correctly segregated nuclei but with uncontracted actomyosin rings. The cytokinesis proteins Cdc3p (a septin), actin, and Iqg1p/Cyk1p (an IQGAP-like protein) appeared to correctly localize in mob1 mutants, suggesting that MOB1 functions subsequent to actomyosin ring assembly. We also examined the subcellular distribution of Mob1p during the cell cycle and found that Mob1p first localized to the spindle pole bodies during mid-anaphase and then localized to a ring at the bud neck just before and during cytokinesis. Localization of Mob1p to the bud neck required CDC3, MEN genes CDC5, CDC14, CDC15, and DBF2, and spindle pole body gene NUD1 but was independent of MYO1. The localization of Mob1p to both spindle poles was abolished in cdc15 and nud1 mutants and was perturbed in cdc5 and cdc14 mutants. These results suggest that the MEN functions during the mitosis-to-G1 transition to control cyclin-CDK inactivation and cytokinesis.

Original languageEnglish (US)
Pages (from-to)6972-6983
Number of pages12
JournalMolecular and Cellular Biology
Volume21
Issue number20
DOIs
StatePublished - Oct 10 2001
Externally publishedYes

Fingerprint

Cytokinesis
Saccharomyces cerevisiae
Spindle Pole Bodies
Actomyosin
Cyclins
Cyclin-Dependent Kinases
Gene Regulatory Networks
Mitosis
Septins
Spindle Poles
Myosin Type II
Anaphase
Cell Separation
Genes
Actins
Cell Cycle
Proteins
Yeasts
Observation

ASJC Scopus subject areas

  • Molecular Biology
  • Cell Biology

Cite this

Saccharomyces cerevisiae Mob1p is required for cytokinesis and mitotic exit. / Luca, F. C.; Mody, M.; Kurischko, C.; Roof, D. M.; Giddings, T. H.; Winey, Mark.

In: Molecular and Cellular Biology, Vol. 21, No. 20, 10.10.2001, p. 6972-6983.

Research output: Contribution to journalArticle

Luca, F. C. ; Mody, M. ; Kurischko, C. ; Roof, D. M. ; Giddings, T. H. ; Winey, Mark. / Saccharomyces cerevisiae Mob1p is required for cytokinesis and mitotic exit. In: Molecular and Cellular Biology. 2001 ; Vol. 21, No. 20. pp. 6972-6983.
@article{11976247c097479b9f2cf3e9d397b115,
title = "Saccharomyces cerevisiae Mob1p is required for cytokinesis and mitotic exit",
abstract = "The Saccharomyces cerevisiae mitotic exit network (MEN) is a conserved set of genes that mediate the transition from mitosis to G1 by regulating mitotic cyclin degradation and the inactivation of cyclin-dependent kinase (CDK). Here, we demonstrate that, in addition to mitotic exit, S. cerevisiae MEN gene MOB1 is required for cytokinesis and cell separation. The cytokinesis defect was evident in mob1 mutants under conditions in which there was no mitotic-exit defect. Observation of live cells showed that yeast myosin II, Myo1p, was present in the contractile ring at the bud neck but that the ring failed to contract and disassemble. The cytokinesis defect persisted for several mitotic cycles, resulting in chains of cells with correctly segregated nuclei but with uncontracted actomyosin rings. The cytokinesis proteins Cdc3p (a septin), actin, and Iqg1p/Cyk1p (an IQGAP-like protein) appeared to correctly localize in mob1 mutants, suggesting that MOB1 functions subsequent to actomyosin ring assembly. We also examined the subcellular distribution of Mob1p during the cell cycle and found that Mob1p first localized to the spindle pole bodies during mid-anaphase and then localized to a ring at the bud neck just before and during cytokinesis. Localization of Mob1p to the bud neck required CDC3, MEN genes CDC5, CDC14, CDC15, and DBF2, and spindle pole body gene NUD1 but was independent of MYO1. The localization of Mob1p to both spindle poles was abolished in cdc15 and nud1 mutants and was perturbed in cdc5 and cdc14 mutants. These results suggest that the MEN functions during the mitosis-to-G1 transition to control cyclin-CDK inactivation and cytokinesis.",
author = "Luca, {F. C.} and M. Mody and C. Kurischko and Roof, {D. M.} and Giddings, {T. H.} and Mark Winey",
year = "2001",
month = "10",
day = "10",
doi = "10.1128/MCB.21.20.6972-6983.2001",
language = "English (US)",
volume = "21",
pages = "6972--6983",
journal = "Molecular and Cellular Biology",
issn = "0270-7306",
publisher = "American Society for Microbiology",
number = "20",

}

TY - JOUR

T1 - Saccharomyces cerevisiae Mob1p is required for cytokinesis and mitotic exit

AU - Luca, F. C.

AU - Mody, M.

AU - Kurischko, C.

AU - Roof, D. M.

AU - Giddings, T. H.

AU - Winey, Mark

PY - 2001/10/10

Y1 - 2001/10/10

N2 - The Saccharomyces cerevisiae mitotic exit network (MEN) is a conserved set of genes that mediate the transition from mitosis to G1 by regulating mitotic cyclin degradation and the inactivation of cyclin-dependent kinase (CDK). Here, we demonstrate that, in addition to mitotic exit, S. cerevisiae MEN gene MOB1 is required for cytokinesis and cell separation. The cytokinesis defect was evident in mob1 mutants under conditions in which there was no mitotic-exit defect. Observation of live cells showed that yeast myosin II, Myo1p, was present in the contractile ring at the bud neck but that the ring failed to contract and disassemble. The cytokinesis defect persisted for several mitotic cycles, resulting in chains of cells with correctly segregated nuclei but with uncontracted actomyosin rings. The cytokinesis proteins Cdc3p (a septin), actin, and Iqg1p/Cyk1p (an IQGAP-like protein) appeared to correctly localize in mob1 mutants, suggesting that MOB1 functions subsequent to actomyosin ring assembly. We also examined the subcellular distribution of Mob1p during the cell cycle and found that Mob1p first localized to the spindle pole bodies during mid-anaphase and then localized to a ring at the bud neck just before and during cytokinesis. Localization of Mob1p to the bud neck required CDC3, MEN genes CDC5, CDC14, CDC15, and DBF2, and spindle pole body gene NUD1 but was independent of MYO1. The localization of Mob1p to both spindle poles was abolished in cdc15 and nud1 mutants and was perturbed in cdc5 and cdc14 mutants. These results suggest that the MEN functions during the mitosis-to-G1 transition to control cyclin-CDK inactivation and cytokinesis.

AB - The Saccharomyces cerevisiae mitotic exit network (MEN) is a conserved set of genes that mediate the transition from mitosis to G1 by regulating mitotic cyclin degradation and the inactivation of cyclin-dependent kinase (CDK). Here, we demonstrate that, in addition to mitotic exit, S. cerevisiae MEN gene MOB1 is required for cytokinesis and cell separation. The cytokinesis defect was evident in mob1 mutants under conditions in which there was no mitotic-exit defect. Observation of live cells showed that yeast myosin II, Myo1p, was present in the contractile ring at the bud neck but that the ring failed to contract and disassemble. The cytokinesis defect persisted for several mitotic cycles, resulting in chains of cells with correctly segregated nuclei but with uncontracted actomyosin rings. The cytokinesis proteins Cdc3p (a septin), actin, and Iqg1p/Cyk1p (an IQGAP-like protein) appeared to correctly localize in mob1 mutants, suggesting that MOB1 functions subsequent to actomyosin ring assembly. We also examined the subcellular distribution of Mob1p during the cell cycle and found that Mob1p first localized to the spindle pole bodies during mid-anaphase and then localized to a ring at the bud neck just before and during cytokinesis. Localization of Mob1p to the bud neck required CDC3, MEN genes CDC5, CDC14, CDC15, and DBF2, and spindle pole body gene NUD1 but was independent of MYO1. The localization of Mob1p to both spindle poles was abolished in cdc15 and nud1 mutants and was perturbed in cdc5 and cdc14 mutants. These results suggest that the MEN functions during the mitosis-to-G1 transition to control cyclin-CDK inactivation and cytokinesis.

UR - http://www.scopus.com/inward/record.url?scp=0034813103&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0034813103&partnerID=8YFLogxK

U2 - 10.1128/MCB.21.20.6972-6983.2001

DO - 10.1128/MCB.21.20.6972-6983.2001

M3 - Article

C2 - 11564880

AN - SCOPUS:0034813103

VL - 21

SP - 6972

EP - 6983

JO - Molecular and Cellular Biology

JF - Molecular and Cellular Biology

SN - 0270-7306

IS - 20

ER -