title: Cyclic GMP controls Rhodospirillum centenum cyst development.
abstract: Adenylyl cyclases are widely distributed across all kingdoms whereas guanylyl cyclases are generally thought to be restricted to eukaryotes. Here we report that the α-proteobacterium Rhodospirillum centenum secretes cGMP when developing cysts and that a guanylyl cyclase deletion strain fails to synthesize cGMP and is defective in cyst formation. The R. centenum cyclase was purified and shown to effectively synthesize cGMP from GTP in vitro, demonstrating that it is a functional guanylyl cyclase. A homologue of the Escherichia coli cAMP receptor protein (CRP) is linked to the guanylyl cyclase and when deleted is deficient in cyst development. Isothermal calorimetry (ITC) and differential scanning fluorimetry (DSF) analyses demonstrate that the recombinant CRP homologue preferentially binds to, and is stabilized by cGMP, but not cAMP. This study thus provides evidence that cGMP has a crucial role in regulating prokaryotic development. The involvement of cGMP in regulating bacterial development has broader implications as several plant-interacting bacteria contain a similar cyclase coupled by the observation that Azospirillum brasilense also synthesizes cGMP when inducing cysts.
authors.affiliation: Indiana University, Bloomington, IN 47405, USA University of California at Berkeley, Berkeley, CA 94720, USA.
authors.forename: Jeremiah N
authors.initials: JN
authors.lastname: Marden
authors.forename: Qian
authors.initials: Q
authors.lastname: Dong
authors.forename: Sugata
authors.initials: S
authors.lastname: Roychowdhury
authors.forename: James E
authors.initials: JE
authors.lastname: Berleman
authors.forename: Carl E
authors.initials: CE
authors.lastname: Bauer
mesh_terms: D000595:Amino Acid Sequence; D002851:Chromatography, High Pressure Liquid; D017124:Conserved Sequence / Q000235:genetics; D002373:Cyclic AMP Receptor Protein / Q000378:metabolism; D006152:Cyclic GMP / Q000378:metabolism*; D006162:Guanylate Cyclase / Q000737:chemistry / Q000378:metabolism; D008954:Models, Biological; D008969:Molecular Sequence Data; D005810:Multigene Family / Q000235:genetics; D009154:Mutation / Q000235:genetics; D016366:Open Reading Frames / Q000235:genetics; D011485:Protein Binding; D012045:Regulatory Sequences, Nucleic Acid / Q000235:genetics; D042182:Rhodospirillum centenum / Q000201:enzymology / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid; D015398:Signal Transduction; D012988:Soil Microbiology; D013045:Species Specificity; D013171:Spores, Bacterial / Q000166:cytology / Q000378:metabolism; D013379:Substrate Specificity; D013489:Suppression, Genetic; D044366:Transition Temperature
chemical_list: D002373:Cyclic AMP Receptor Protein; D006162:Guanylate Cyclase; D006152:Cyclic GMP