title: Cell-wall remodeling drives engulfment duringBacillus subtilissporulation.
abstract: When starved, the Gram-positive bacteriumBacillus subtilisforms durable spores for survival. Sporulation initiates with an asymmetric cell division, creating a large mother cell and a small forespore. Subsequently, the mother cell membrane engulfs the forespore in a phagocytosis-like process. However, the force generation mechanism for forward membrane movement remains unknown. Here, we show that membrane migration is driven by cell wall remodeling at the leading edge of the engulfing membrane, with peptidoglycan synthesis and degradation mediated by penicillin binding proteins in the forespore and a cell wall degradation protein complex in the mother cell. We propose a simple model for engulfment in which the junction between the septum and the lateral cell wall moves around the forespore by a mechanism resembling the 'template model'. Hence, we establish a biophysical mechanism for the creation of a force for engulfment based on the coordination between cell wall synthesis and degradation.
authors.affiliation: Department of Life Sciences, Imperial College London, London, United Kingdom.|Centre for Integrative Systems Biology and Bioinformatics, Imperial College London, London, United Kingdom.
authors.forename: Nikola
authors.initials: N
authors.lastname: Ojkic
authors.affiliation: Division of Biological Sciences, University of California, San Diego, La Jolla, United States.
authors.forename: Javier
authors.initials: J
authors.lastname: López-Garrido
authors.affiliation: Division of Biological Sciences, University of California, San Diego, La Jolla, United States.
authors.forename: Kit
authors.initials: K
authors.lastname: Pogliano
authors.affiliation: Department of Life Sciences, Imperial College London, London, United Kingdom.|Centre for Integrative Systems Biology and Bioinformatics, Imperial College London, London, United Kingdom.
authors.forename: Robert G
authors.identifier: 0000-0003-1379-659X
authors.initials: RG
authors.lastname: Endres
mesh_terms: D001412:Bacillus subtilis / Q000235:genetics* / Q000254:growth & development; D055592:Biophysical Phenomena; D002455:Cell Division / Q000235:genetics; D002462:Cell Membrane / Q000737:chemistry / Q000235:genetics*; D002473:Cell Wall / Q000737:chemistry / Q000235:genetics*; D010587:Phagocytosis / Q000235:genetics; D013171:Spores, Bacterial / Q000235:genetics* / Q000254:growth & development
keywords: B. subtilis; cell wall; computational biology; infectious disease; microbiology; peptidoglycan remodeling; sporulation; systems biology