title: Membrane reconstitution of FtsZ-ZipA complex inside giant spherical vesicles made of E. coli lipids: large membrane dilation and analysis of membrane plasticity.
abstract: During the division process of Escherichia coli, the globular protein FtsZ is early recruited at the constriction site. The Z-ring, based on FtsZ filaments associated to the inner cell membrane, has been postulated to exert constriction forces. Membrane anchoring is mediated by ZipA, an essential transmembrane protein able to specifically bind FtsZ. In this work, an artificial complex of FtsZ-ZipA has been reconstituted at the inner side of spherical giant unilamellar vesicles made of E. coli lipids. Under these conditions, FtsZ polymerization, triggered when a caged GTP analogue is UV-irradiated, was followed by up to 40% vesicle inflation. The homogeneous membrane dilation was accompanied by the visualization of discrete FtsZ assemblies at the membrane. Complementary rheological data revealed enhanced elasticity under lateral dilation. This explains why vesicles can undergo large dilations in the regime of mechanical stability. A mechanical role for FtsZ polymers as promoters of membrane softening and plasticization is hypothesized.
authors.affiliation: Departamento de Química Física I, Universidad Complutense, 28040 Madrid, Spain. ivanlopez@quim.ucm.es
authors.forename: I
authors.initials: I
authors.lastname: López-Montero
authors.forename: P
authors.initials: P
authors.lastname: López-Navajas
authors.forename: J
authors.initials: J
authors.lastname: Mingorance
authors.forename: M
authors.initials: M
authors.lastname: Vélez
authors.forename: M
authors.initials: M
authors.lastname: Vicente
authors.forename: F
authors.initials: F
authors.lastname: Monroy
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry*; D001703:Biophysics / Q000379:methods; D002352:Carrier Proteins / Q000737:chemistry*; D018797:Cell Cycle Proteins / Q000737:chemistry*; D002462:Cell Membrane / Q000378:metabolism; D048749:Cytokinesis; D003598:Cytoskeletal Proteins / Q000737:chemistry*; D004926:Escherichia coli / Q000201:enzymology / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000737:chemistry*; D006160:Guanosine Triphosphate / Q000737:chemistry; D008051:Lipid Bilayers / Q000737:chemistry; D008055:Lipids / Q000737:chemistry*; D008856:Microscopy, Fluorescence / Q000379:methods; D012212:Rheology / Q000379:methods; D058615:Synthetic Biology / Q000379:methods; D013816:Thermodynamics; D014461:Ultracentrifugation; D014466:Ultraviolet Rays
chemical_list: D001426:Bacterial Proteins; D002352:Carrier Proteins; D018797:Cell Cycle Proteins; D003598:Cytoskeletal Proteins; D029968:Escherichia coli Proteins; C071525:FtsZ protein, Bacteria; D008051:Lipid Bilayers; D008055:Lipids; C103795:ZipA protein, E coli; D006160:Guanosine Triphosphate