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Updated: May 24, 2025

Spatiotemporal Analysis of Cytokinetic Events in Fission Yeast
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Spatiotemporal Analysis of Cytokinetic Events in Fission Yeast

Published on: February 20, 2017

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PP2A-B56 regulates Mid1 protein levels for proper cytokinesis in fission yeast

Madeline L Chrupcala1, James B Moseley1

  • 1Department of Biochemistry and Cell Biology, The Geisel School of Medicine at Dartmouth, Hanover, NH.

Molecular Biology of the Cell
|March 5, 2025
PubMed

Insights

The protein phosphatase PP2A-B56 is crucial for cell division by maintaining Mid1 protein levels. Its absence causes asymmetric cell division due to misplaced cytokinetic rings in fission yeast.

Area of Science:

  • Cell Biology
  • Molecular Biology
  • Genetics

Background:

  • Protein phosphorylation regulates cell division, including cytokinesis.
  • Mid1, an anillin-like protein, establishes the cell division plane in fission yeast and is regulated by phosphorylation.
  • No protein phosphatases were previously known to regulate Mid1.

Purpose of the Study:

  • To investigate the role of protein phosphatases in regulating Mid1 and cytokinesis.
  • To identify novel regulators of the cell division process.

Main Methods:

  • Studied fission yeast mutants lacking the PP2A-B56 subunit (par1∆).
  • Assessed cell division, cytokinetic ring assembly, and Mid1 protein levels.
  • Investigated the effect of restoring Mid1 expression in par1∆ mutants.

Main Results:

  • PP2A-B56 is essential for proper cytokinesis by promoting Mid1 protein levels.
  • par1∆ cells exhibit asymmetric division with misplaced cytokinetic rings.
  • Reduced Mid1 protein levels in par1∆ mutants lead to defects at the cytokinetic ring.
  • Restoring Mid1 expression rescues the cytokinesis defects in par1∆ cells.

Conclusions:

  • Identified a novel pathway where PP2A-B56 regulates cytokinesis through Mid1.
  • This finding has implications for understanding cytokinesis control in various organisms.
  • PP2A-B56 plays a critical role in maintaining Mid1 protein homeostasis for accurate cell division.

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