PMID:19602145

Citation	Kobayashi, H, De Nisco, NJ, Chien, P, Simmons, LA and Walker, GC (2009) Sinorhizobium meliloti CpdR1 is critical for co-ordinating cell cycle progression and the symbiotic chronic infection. Mol. Microbiol. 73:586-600
Abstract	ATP-driven proteolysis plays a major role in regulating the bacterial cell cycle, development and stress responses. In the nitro -fixing symbiosis with host plants, Sinorhizobium meliloti undergoes a profound cellular differentiation, including endoreduplication of the ome. The regulatory mechanisms governing the alterations of the S. meliloti cell cycle in planta are largely unknown. Here, we report the characterization of two cpdR homologues, cpdR1 and cpdR2, of S. meliloti that encode single-domain response regulators. In Caulobacter crescentus, CpdR controls the polar localization of the ClpXP protease, thereby mediating the regulated proteolysis of key protein(s), such as CtrA, involved in cell cycle progression. The S. meliloti cpdR1-null mutant can invade the host cytoplasm, however, the intracellular bacteria are unable to differentiate into bacteroids. We show that S. meliloti CpdR1 has a polar localization pattern and a role in ClpX positioning similar to C. crescentus CpdR, suggesting a conserved function of CpdR proteins among alpha-proteobacteria. However, in S. meliloti, free-living cells of the cpdR1-null mutant show a striking morphology of irregular coccoids and aberrant DNA replication. Thus, we demonstrate that CpdR1 mediates the co-ordination of cell cycle events, which are critical for both the free-living cell division and the differentiation required for the chronic intracellular infection.
Links	PubMed PMC2756024 Online version:10.1111/j.1365-2958.2009.06794.x
Keywords	Bacterial Proteins/genetics; Bacterial Proteins/metabolism; Cell Cycle; DNA Replication; DNA, Bacterial/biosynthesis; Gene Expression Profiling; Gene Expression Regulation, Bacterial; Mutagenesis, Insertional; Sinorhizobium meliloti/cytology; Sinorhizobium meliloti/genetics; Sinorhizobium meliloti/metabolism; Symbiosis
edit table

Annotations

Gene product	Qualifier	GO Term	Evidence Code	with/from	Aspect	Extension	Notes	Status
RHIME:Q92M29	part_of	GO:0060187: cell pole	ECO:0000314: direct assay evidence used in manual assertion		C		Seeded From UniProt	complete

References

See Help:References for how to manage references in GONUTS.