Characterization and subcellular localization of a bacterial flotillin homologue

Microbiology (Reading). 2009 Jun;155(Pt 6):1786-1799. doi: 10.1099/mic.0.025312-0. Epub 2009 Apr 21.


The process of endospore formation in Bacillus subtilis is complex, requiring the generation of two distinct cell types, a forespore and larger mother cell. The development of these cell types is controlled and regulated by cell type-specific gene expression, activated by a sigma-factor cascade. Activation of these cell type-specific sigma factors is coupled with the completion of polar septation. Here, we describe a novel protein, YuaG, a eukaryotic reggie/flotillin homologue that is involved in the early stages of sporulation of the Gram-positive model organism B. subtilis. YuaG localizes in discrete foci in the membrane and is highly dynamic. Purification of detergent-resistant membranes revealed that YuaG is associated with negatively charged phospholipids, e.g. phosphatidylglycerol (PG) or cardiolipin (CL). However, localization of YuaG is not always dependent on PG/CL in vivo. A yuaG disruption strain shows a delay in the onset of sporulation along with reduced sporulation efficiency, where the spores develop to a certain stage and then appear to be trapped at this stage. Our results indicate that YuaG is involved in the early stage of spore development, probably playing a role in the signalling cascade at the onset of sporulation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacillus subtilis / physiology*
  • Bacterial Proteins / physiology
  • Cardiolipins / metabolism
  • Gene Expression Regulation, Bacterial
  • Genes, Bacterial / physiology
  • Green Fluorescent Proteins
  • Intracellular Space / metabolism*
  • Membrane Microdomains / metabolism
  • Membrane Proteins / chemistry
  • Membrane Proteins / physiology*
  • Recombinant Fusion Proteins / biosynthesis
  • Sequence Homology, Amino Acid*
  • Sigma Factor / metabolism
  • Spores, Bacterial


  • Bacterial Proteins
  • Cardiolipins
  • Membrane Proteins
  • Recombinant Fusion Proteins
  • Sigma Factor
  • flotillins
  • Green Fluorescent Proteins