title: Crucial role for membrane fluidity in proliferation of primitive cells.
abstract: The cell wall is a defining structural feature of the bacterial subkingdom. However, most bacteria are capable of mutating into a cell-wall-deficient "L-form" state, requiring remarkable physiological and structural adaptations. L-forms proliferate by an unusual membrane deformation and scission process that is independent of the conserved and normally essential FtsZ based division machinery, and which may provide a model for the replication of primitive cells. Candidate gene screening revealed no requirement for the cytoskeletal systems that might actively drive membrane deformation or scission. Instead, we uncovered a crucial role for branched-chain fatty acid (BCFA) synthesis. BCFA-deficient mutants grow and undergo pulsating shape changes, but membrane scission fails, abolishing the separation of progeny cells. The failure in scission is associated with a reduction in membrane fluidity. The results identify a step in L-form proliferation and demonstrate that purely biophysical processes may have been sufficient for proliferation of primitive cells.
authors: Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, The Medical School, Newcastle University, Newcastle upon Tyne NE2 4HH, UK.
authors: Romain
authors: R
authors: Mercier
authors: Patricia
authors: P
authors: Domínguez-Cuevas
authors: Jeff
authors: J
authors: Errington
mesh_terms: D001412:Bacillus subtilis / Q000166:cytology / Q000235:genetics / Q000502:physiology*; D001426:Bacterial Proteins / Q000235:genetics / Q000502:physiology; D002455:Cell Division / Q000502:physiology; D002462:Cell Membrane / Q000502:physiology*; D049109:Cell Proliferation; D002473:Cell Wall / Q000502:physiology; D003599:Cytoskeleton / Q000502:physiology; D005227:Fatty Acids / Q000502:physiology; D007740:L Forms / Q000235:genetics / Q000502:physiology*; D008560:Membrane Fluidity / Q000502:physiology*; D009154:Mutation / Q000235:genetics
chemical_list: D001426:Bacterial Proteins; D005227:Fatty Acids