Bacterial motility complexes require the actin-like protein, MreB and the Ras homologue, MglA

EMBO J. 2010 Jan 20;29(2):315-26. doi: 10.1038/emboj.2009.356. Epub 2009 Dec 3.

Abstract

Gliding motility in the bacterium Myxococcus xanthus uses two motility engines: S-motility powered by type-IV pili and A-motility powered by uncharacterized motor proteins and focal adhesion complexes. In this paper, we identified MreB, an actin-like protein, and MglA, a small GTPase of the Ras superfamily, as essential for both motility systems. A22, an inhibitor of MreB cytoskeleton assembly, reversibly inhibited S- and A-motility, causing rapid dispersal of S- and A-motility protein clusters, FrzS and AglZ. This suggests that the MreB cytoskeleton is involved in directing the positioning of these proteins. We also found that a DeltamglA motility mutant showed defective localization of AglZ and FrzS clusters. Interestingly, MglA-YFP localization mimicked both FrzS and AglZ patterns and was perturbed by A22 treatment, consistent with results indicating that both MglA and MreB bind to motility complexes. We propose that MglA and the MreB cytoskeleton act together in a pathway to localize motility proteins such as AglZ and FrzS to assemble the A-motility machineries. Interestingly, M. xanthus motility systems, like eukaryotic systems, use an actin-like protein and a small GTPase spatial regulator.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacterial Adhesion*
  • Bacterial Proteins / analysis
  • Bacterial Proteins / genetics
  • Bacterial Proteins / metabolism*
  • Cell Polarity
  • Cytoskeleton / metabolism
  • Molecular Motor Proteins / analysis
  • Molecular Motor Proteins / metabolism*
  • Mutation
  • Myxococcus xanthus / cytology*
  • Myxococcus xanthus / metabolism
  • Thiourea / analogs & derivatives
  • Thiourea / pharmacology

Substances

  • Bacterial Proteins
  • Molecular Motor Proteins
  • MglA protein, Myxococcus xanthus
  • 2,6-dichlorobenzylthiopseudourea
  • Thiourea