Pom1 kinase links division plane position to cell polarity by regulating Mid1p cortical distribution

J Cell Sci. 2006 Nov 15;119(Pt 22):4710-8. doi: 10.1242/jcs.03261. Epub 2006 Oct 31.

Abstract

In fission yeast, Mid1p, a major determinant for division plane position, defines a medial cortical compartment where it recruits myosin II at the onset of mitosis to initiate contractile ring assembly. How Mid1p is restricted to the medial cortex is unknown. We report here that in a pom1 polarity mutant, which displays a monopolar growth pattern, Mid1p distribution expands towards the non-growing cell tip, uncoupling Mid1p localization from nuclear position. This accounts for the displacement of the contractile ring during mitosis. By contrast, Mid1p localization is normal in a bud6Delta strain, indicating that Mid1p misdistribution is not a general consequence of monopolar growth. We conclude that Pom1 kinase acts as a negative regulator of Mid1p distribution, excluding Mid1p from non-growing ends, whereas a Pom1-independent mechanism prevents Mid1p association with growing ends. Our work therefore provides evidence that cell polarity regulators influence the distribution of Mid1p, linking division plane position to cell polarity.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Compartmentation
  • Cell Polarity
  • Cytokinesis
  • Mutation
  • Protein Kinases / genetics
  • Protein Kinases / metabolism*
  • Schizosaccharomyces / metabolism
  • Schizosaccharomyces / physiology*
  • Schizosaccharomyces pombe Proteins / genetics
  • Schizosaccharomyces pombe Proteins / metabolism*
  • Subcellular Fractions / metabolism

Substances

  • Mid1 protein, S pombe
  • Schizosaccharomyces pombe Proteins
  • Protein Kinases
  • Pom1 protein, S pombe