title: Characterization and subcellular localization of a bacterial flotillin homologue.
abstract: 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.
authors.affiliation: Institut für Biochemie, Universität zu Köln, Zülpicher Str. 47, D-50674 Köln, Germany.
authors.forename: Catriona
authors.initials: C
authors.lastname: Donovan
authors.affiliation: Institut für Biochemie, Universität zu Köln, Zülpicher Str. 47, D-50674 Köln, Germany.
authors.forename: Marc
authors.initials: M
authors.lastname: Bramkamp
mesh_terms: D001412:Bacillus subtilis / Q000502:physiology*; D001426:Bacterial Proteins / Q000502:physiology; D002308:Cardiolipins / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial / Q000502:physiology; D049452:Green Fluorescent Proteins; D042541:Intracellular Space / Q000378:metabolism*; D021962:Membrane Microdomains / Q000378:metabolism; D008565:Membrane Proteins / Q000737:chemistry / Q000502:physiology*; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis; D017386:Sequence Homology, Amino Acid; D012808:Sigma Factor / Q000378:metabolism; D013171:Spores, Bacterial
chemical_list: D001426:Bacterial Proteins; D002308:Cardiolipins; D008565:Membrane Proteins; D011993:Recombinant Fusion Proteins; D012808:Sigma Factor; C106354:flotillins; D049452:Green Fluorescent Proteins