Molecular analysis of the key cytokinetic components of cyanobacteria: FtsZ, ZipN and MinCDE.
Using a bacterial two-hybrid system and a combination of in vivo and in vitro assays that take advantage of the green fluorescent reporter protein (GFP), we have investigated the localization and the protein-protein interaction of several key components of the cytokinetic machinery of cyanobacteria (i.e. the progenitor of chloroplast). We demonstrate that (i) the ftsZ and zipN genes are essential for the viability of the model cyanobacterium Synechocystis sp. PCC 6803, whereas the minCDE cluster is dispensable for cell growth; (ii) the GTP-binding domain of FtsZ is crucial to FtsZ assembly into the septal ring at mid-cell; (iii) the Z-ring of deeply constricted daughter cells is oriented perpendicularly to the mother Z-ring, showing that Synechocystis divides in alternating perpendicular planes; (iv) the MinCDE system affects the morphology of the cell, as well as the position and the shape of FtsZ structures; and (v) MinD is targeted to cell membranes in a process involving its C-terminal amphipathic helix, but not its ATP-binding region. Finally, we have also characterized a novel Z-interacting protein, ZipN, the N-terminal DnaJ domain of which is critical to the decoration of the Z-ring, and we report that this process is independent of MinCDE.
Mazouni
Khalil
K
Service de Biochimie et Génétique Moléculaire, CEA Saclay, 91191 Gif Sur Yvette Cedex, France.
Domain
Francis
F
Cassier-Chauvat
Corinne
C
Chauvat
Franck
F
D001426:Bacterial Proteins / Q000235:genetics / Q000502:physiology*; D002455:Cell Division; D000458:Cyanobacteria / Q000166:cytology* / Q000235:genetics*; D003598:Cytoskeletal Proteins / Q000235:genetics / Q000502:physiology*; D019204:GTP-Binding Proteins / Q000235:genetics / Q000502:physiology; D005798:Genes, Bacterial; D020043:Genes, Essential; D017930:Genes, Reporter; D049452:Green Fluorescent Proteins; D050956:HSP40 Heat-Shock Proteins; D006360:Heat-Shock Proteins / Q000378:metabolism; D008164:Luminescent Proteins / Q000378:metabolism; D008565:Membrane Proteins / Q000235:genetics / Q000502:physiology; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D021381:Protein Transport; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D020798:Two-Hybrid System Techniques
D001426:Bacterial Proteins; D003598:Cytoskeletal Proteins; C071525:FtsZ protein, Bacteria; D050956:HSP40 Heat-Shock Proteins; D006360:Heat-Shock Proteins; D008164:Luminescent Proteins; D008565:Membrane Proteins; C080466:MinC protein, Bacteria; D011993:Recombinant Fusion Proteins; D049452:Green Fluorescent Proteins; D019204:GTP-Binding Proteins