Phosphorylation-dependent regulation of septin dynamics during the cell cycle

Dev Cell. 2003 Mar;4(3):345-57. doi: 10.1016/s1534-5807(03)00061-3.

Abstract

Septins are GTPases involved in cytokinesis. In yeast, they form a ring at the cleavage site. Using FRAP, we show that septins are mobile within the ring at bud emergence and telophase and are immobile during S, G2, and M phases. Immobilization of the septins is dependent on both Cla4, a PAK-like kinase, and Gin4, a septin-dependent kinase that can phosphorylate the septin Shs1/Sep7. Induction of septin ring dynamics in telophase is triggered by the translocation of Rts1, a kinetochore-associated regulatory subunit of PP2A phosphatase, to the bud neck and correlates with Rts1-dependent dephosphorylation of Shs1. In rts1-Delta cells, the actomyosin ring contracts properly but cytokinesis fails. Together our results implicate septins in a late step of cytokinesis and indicate that proper regulation of septin dynamics, possibly through the control of their phosphorylation state, is required for the completion of cytokinesis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Cycle / physiology*
  • Cell Cycle Proteins / genetics
  • Cell Cycle Proteins / metabolism*
  • Cell Division / physiology*
  • Cells, Cultured
  • Cyclin-Dependent Kinases / genetics
  • Cyclin-Dependent Kinases / metabolism
  • Cytoskeletal Proteins / genetics
  • Cytoskeletal Proteins / metabolism
  • DNA Restriction Enzymes / genetics
  • DNA Restriction Enzymes / metabolism
  • Fluorescence Resonance Energy Transfer
  • Organelles / metabolism
  • Organelles / ultrastructure
  • Phosphoprotein Phosphatases / genetics
  • Phosphoprotein Phosphatases / metabolism
  • Phosphorylation
  • Profilins
  • Protein Subunits / genetics
  • Protein Subunits / metabolism
  • Protein-Serine-Threonine Kinases / genetics
  • Protein-Serine-Threonine Kinases / metabolism
  • Saccharomyces cerevisiae / cytology
  • Saccharomyces cerevisiae / metabolism*
  • Saccharomyces cerevisiae Proteins / genetics
  • Saccharomyces cerevisiae Proteins / metabolism*

Substances

  • CDC12 protein, S cerevisiae
  • CDC3 protein, S cerevisiae
  • Cell Cycle Proteins
  • Cytoskeletal Proteins
  • Profilins
  • Protein Subunits
  • SHS1 protein, S cerevisiae
  • Saccharomyces cerevisiae Proteins
  • CLA4 protein, S cerevisiae
  • GIN4 protein, S cerevisiae
  • Protein-Serine-Threonine Kinases
  • Cyclin-Dependent Kinases
  • DNA Restriction Enzymes
  • endodeoxyribonuclease Rts1
  • Phosphoprotein Phosphatases