Regulation of dynamic polarity switching in bacteria by a Ras-like G-protein and its cognate GAP

• Simone Leonardy ^[1] ; Mandy Miertzschke ^[2] ; Iryna Bulyha ^[1] ; Eva Sperling ^[1] ; Alfred Wittinghofer ^[2] ; Lotte Søgaard-Andersen ^[1]
  1. [1] Max Planck Institute for Terrestrial Microbiology

     Max Planck Institute for Terrestrial Microbiology

     Landkreis Marburg-Biedenkopf, Alemania

     
  2. [2] Department of Structural Biology, Max Planck Institute for Molecular Physiology, Dortmund, Germany
• Localización: EMBO journal: European Molecular Biology Organization, ISSN 0261-4189, Vol. 29, Nº. 14, 2010, págs. 2276-2289
• Idioma: inglés
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• Resumen

  • The rod-shaped cells of the bacterium Myxococcus xanthus move uni-directionally and occasionally undergo reversals during which the leading/lagging polarity axis is inverted. Cellular reversals depend on pole-to-pole relocation of motility proteins that localize to the cell poles between reversals. We show that MglA is a Ras-like G-protein and acts as a nucleotide-dependent molecular switch to regulate motility and that MglB represents a novel GTPase-activating protein (GAP) family and is the cognate GAP of MglA. Between reversals, MglA/GTP is restricted to the leading and MglB to the lagging pole defining the leading/lagging polarity axis. For reversals, the Frz chemosensory system induces the relocation of MglA/GTP to the lagging pole causing an inversion of the leading/lagging polarity axis. MglA/GTP stimulates motility by establishing correct polarity of motility proteins between reversals and reversals by inducing their pole-to-pole relocation. Thus, the function of Ras-like G-proteins and their GAPs in regulating cell polarity is found not only in eukaryotes, but also conserved in bacteria.