The actin homologue MreB organizes the bacterial cell membrane

Nat Commun. 2014 Mar 7;5:3442. doi: 10.1038/ncomms4442.

Abstract

The eukaryotic cortical actin cytoskeleton creates specific lipid domains, including lipid rafts, which determine the distribution of many membrane proteins. Here we show that the bacterial actin homologue MreB displays a comparable activity. MreB forms membrane-associated filaments that coordinate bacterial cell wall synthesis. We noticed that the MreB cytoskeleton influences fluorescent staining of the cytoplasmic membrane. Detailed analyses combining an array of mutants, using specific lipid staining techniques and spectroscopic methods, revealed that MreB filaments create specific membrane regions with increased fluidity (RIFs). Interference with these fluid lipid domains (RIFs) perturbs overall lipid homeostasis and affects membrane protein localization. The influence of MreB on membrane organization and fluidity may explain why the active movement of MreB stimulates membrane protein diffusion. These novel MreB activities add additional complexity to bacterial cell membrane organization and have implications for many membrane-associated processes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Actins / genetics
  • Actins / metabolism
  • Bacillus subtilis / genetics
  • Bacillus subtilis / metabolism
  • Bacterial Proteins / genetics
  • Bacterial Proteins / metabolism*
  • Blotting, Western
  • Carbonyl Cyanide m-Chlorophenyl Hydrazone / pharmacology
  • Cell Membrane / chemistry
  • Cell Membrane / metabolism*
  • Cytoskeletal Proteins / genetics
  • Cytoskeletal Proteins / metabolism*
  • Cytoskeleton / drug effects
  • Cytoskeleton / metabolism*
  • Green Fluorescent Proteins / genetics
  • Green Fluorescent Proteins / metabolism
  • Lipid Bilayers / chemistry
  • Lipid Bilayers / metabolism
  • Membrane Fluidity / drug effects
  • Membrane Proteins / metabolism
  • Microscopy, Fluorescence
  • Mutation
  • Oxazines / chemistry
  • Protein Transport / drug effects
  • Proton Ionophores / pharmacology
  • Time-Lapse Imaging

Substances

  • Actins
  • Bacterial Proteins
  • Cytoskeletal Proteins
  • Lipid Bilayers
  • Membrane Proteins
  • Oxazines
  • Proton Ionophores
  • Green Fluorescent Proteins
  • Carbonyl Cyanide m-Chlorophenyl Hydrazone
  • nile red