A novel checkpoint pathway controls actomyosin ring constriction trigger in fission yeast

Elife. 2020 Oct 26:9:e59333. doi: 10.7554/eLife.59333.

Abstract

In fission yeast, the septation initiation network (SIN) ensures temporal coordination between actomyosin ring (CAR) constriction with membrane ingression and septum synthesis. However, questions remain about CAR regulation under stress conditions. We show that Rgf1p (Rho1p GEF), participates in a delay of cytokinesis under cell wall stress (blankophor, BP). BP did not interfere with CAR assembly or the rate of CAR constriction, but did delay the onset of constriction in the wild type cells but not in the rgf1Δ cells. This delay was also abolished in the absence of Pmk1p, the MAPK of the cell integrity pathway (CIP), leading to premature abscission and a multi-septated phenotype. Moreover, cytokinesis delay correlates with maintained SIN signaling and depends on the SIN to be achieved. Thus, we propose that the CIP participates in a checkpoint, capable of triggering a CAR constriction delay through the SIN pathway to ensure that cytokinesis terminates successfully.

Keywords: Rho1 GEF; S. pombe; actomyosin ring constriction; cell biology; cell wall; cytokinesis; fission yeast; stress.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Actomyosin / genetics
  • Actomyosin / metabolism*
  • Cytokinesis
  • Guanine Nucleotide Exchange Factors / genetics
  • Guanine Nucleotide Exchange Factors / metabolism
  • Mitogen-Activated Protein Kinases / genetics
  • Mitogen-Activated Protein Kinases / metabolism
  • Schizosaccharomyces / cytology*
  • Schizosaccharomyces / genetics
  • Schizosaccharomyces / metabolism*
  • Schizosaccharomyces pombe Proteins / genetics
  • Schizosaccharomyces pombe Proteins / metabolism

Substances

  • Guanine Nucleotide Exchange Factors
  • Rgf1 protein, S pombe
  • Schizosaccharomyces pombe Proteins
  • Actomyosin
  • Mitogen-Activated Protein Kinases
  • Pmk1 protein, S pombe