Cyclic GMP controls Rhodospirillum centenum cyst development
Article first published online: 9 JAN 2011
© 2011 Blackwell Publishing Ltd
Volume 79, Issue 3, pages 600–615, February 2011
How to Cite
Marden, J. N., Dong, Q., Roychowdhury, S., Berleman, J. E. and Bauer, C. E. (2011), Cyclic GMP controls Rhodospirillum centenum cyst development. Molecular Microbiology, 79: 600–615. doi: 10.1111/j.1365-2958.2010.07513.x
- Issue published online: 24 JAN 2011
- Article first published online: 9 JAN 2011
- Accepted 12 December, 2010.
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.