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Updated: Aug 18, 2026

Fluorescence Live-cell Imaging of the Complete Vegetative Cell Cycle of the Slow-growing Social Bacterium Myxococcus xanthus
11:45

Fluorescence Live-cell Imaging of the Complete Vegetative Cell Cycle of the Slow-growing Social Bacterium Myxococcus xanthus

Published on: June 20, 2018

Pph1 from Myxococcus xanthus is a protein phosphatase involved in vegetative growth and development

A Treuner-Lange1, M J Ward, D R Zusman

  • 1Department of Molecular and Cell Biology, 401 Barker Hall, University of California, Berkeley, CA 94720-3204, USA.

Molecular Microbiology
|April 12, 2001
PubMed

Insights

The study identifies the first Ser/Thr protein phosphatase gene, pph1, in Myxococcus xanthus. This phosphatase is crucial for bacterial development, swarming, and spore formation, interacting with a key protein kinase.

Area of Science:

  • Microbiology
  • Molecular Biology
  • Biochemistry

Background:

  • Myxococcus xanthus exhibits complex behaviors like swarming and fruiting body formation, regulated by Ser/Thr protein kinases.
  • The role of protein phosphatases in M. xanthus development was previously unknown.

Purpose of the Study:

  • To identify and characterize the first Ser/Thr protein phosphatase gene (pph1) in Myxococcus xanthus.
  • To investigate the function of Pph1 in M. xanthus vegetative growth and development.

Main Methods:

  • DNA sequence analysis of pph1.
  • Purification and enzymatic activity assay of recombinant Pph1.
  • Construction and analysis of a pph1 null mutant.
  • Yeast two-hybrid system for protein interaction studies.

Main Results:

  • Pph1 encodes a 28-kDa protein homologous to eukaryotic PP2C phosphatases, representing a novel bacterial phosphatase group.
  • Recombinant Pph1 exhibits Mn2+/Mg2+-dependent, okadaic acid-resistant phosphatase activity.
  • Pph1 expression peaks during early aggregation; pph1 mutant shows defects in swarming, sporulation, and fruiting body formation.
  • Pph1 interacts with the negative developmental effector Pkn5, suggesting a link with Pkn2-type kinases.

Conclusions:

  • Pph1 is a functional PP2C phosphatase essential for M. xanthus development.
  • Pph1 plays a critical role in regulating swarming, spore formation, and multicellular development.
  • The interaction between Pph1 and Pkn5 highlights a regulatory mechanism involving protein kinases and phosphatases in M. xanthus.

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