title: Imaging-based identification of a critical regulator of FtsZ protofilament curvature in Caulobacter.
abstract: FtsZ is an essential bacterial GTPase that polymerizes at midcell, recruits the division machinery, and may generate constrictive forces necessary for cytokinesis. However, many of the mechanistic details underlying these functions are unknown. We sought to identify FtsZ-binding proteins that influence FtsZ function in Caulobacter crescentus. Here, we present a microscopy-based screen through which we discovered two FtsZ-binding proteins, FzlA and FzlC. FzlA is conserved in α-proteobacteria and was found to be functionally critical for cell division in Caulobacter. FzlA altered FtsZ structure both in vivo and in vitro, forming stable higher-order structures that were resistant to depolymerization by MipZ, a spatial determinant of FtsZ assembly. Electron microscopy revealed that FzlA organizes FtsZ protofilaments into striking helical bundles. The degree of curvature induced by FzlA depended on the nucleotide bound to FtsZ. Induction of FtsZ curvature by FzlA carries implications for regulating FtsZ function by modulating its superstructure.
authors.affiliation: Department of Developmental Biology, Stanford University School of Medicine, Stanford, CA 94305, USA. egoley@stanford.edu
authors.forename: Erin D
authors.initials: ED
authors.lastname: Goley
authors.forename: Natalie A
authors.initials: NA
authors.lastname: Dye
authors.forename: John N
authors.initials: JN
authors.lastname: Werner
authors.forename: Zemer
authors.initials: Z
authors.lastname: Gitai
authors.forename: Lucy
authors.initials: L
authors.lastname: Shapiro
mesh_terms: D000251:Adenosine Triphosphatases / Q000378:metabolism; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure; D016935:Caulobacter crescentus / Q000235:genetics / Q000378:metabolism*; D002453:Cell Cycle / Q000502:physiology; D002455:Cell Division / Q000502:physiology; D048430:Cell Shape / Q000235:genetics; D003598:Cytoskeletal Proteins / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure; D015870:Gene Expression / Q000235:genetics; D006153:Guanosine Diphosphate / Q000378:metabolism; D006160:Guanosine Triphosphate / Q000031:analogs & derivatives / Q000378:metabolism; D046529:Microscopy, Electron, Transmission; D008857:Microscopy, Interference; D017351:N-Acetylglucosaminyltransferases / Q000235:genetics / Q000378:metabolism; D058105:Polymerization; D011485:Protein Binding / Q000502:physiology; D025941:Protein Interaction Mapping / Q000379:methods; D055503:Protein Multimerization / Q000502:physiology; D020836:Protein Structure, Quaternary / Q000502:physiology*
chemical_list: D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D003598:Cytoskeletal Proteins; C071525:FtsZ protein, Bacteria; D006153:Guanosine Diphosphate; C004805:5'-guanylylmethylenebisphosphonate; D006160:Guanosine Triphosphate; D017351:N-Acetylglucosaminyltransferases; C064057:UDP-N-acetylglucosamine-N-acetylmuramyl-(pentapeptide)pyrophosphoryl-undecaprenol N-acetylglucosamine transferase; D000251:Adenosine Triphosphatases