Disease relevance of osmC

• Growth-phase-dependent expression of the osmotically inducible gene osmC of Escherichia coli K-12 [1].
• One of two osmC homologs in Bacillus subtilis is part of the sigmaB-dependent general stress regulon [2].
• To determine if these two subfamilies are functionally distinct, ohr and osmC in Pseudomonas aeruginosa (a bacterium with one representative from each subfamily) were analysed [3].

High impact information on osmC

• We find that RprA synthesis is regulated by the RcsC/RcsB phosphorelay system, previously found to regulate capsule synthesis and promoters of ftsZ and osmC [4].
• Yet, under our experimental conditions, the subsequent expression of the osmC-lacZ fusion was equivalent to that obtained from the tandem promoters [5].
• The sequence of an osmC-phoA gene fusion confirmed the osmC reading frame [5].
• The expression of this operon fusion demonstrated that osmC regulation occurs at the transcriptional level [5].
• A deletion of osmC from the E. coli chromosome was constructed by gene replacement, demonstrating that it is not an essential gene [5].

Biological context of osmC

• All the sequences necessary for osmotic regulation of both promoters are located within a 137 base-pair DNA fragment extending from position -95 to +42 with respect to the putative osmC translation start [5].
• Only ohr mutants are hypersensitive to organic peroxide, and this phenotype can be restored by complementation with ohr but not osmC [3].
• Mutants in osmC, a member of the rpoS regulon, also exhibited reduced survival and increased sensitivity to oxidative stress [6].
• The osmCp promoter region was subcloned and a lac operon fusion transcribed under osmCp control was constructed [5].

Associations of osmC with chemical compounds

• In contrast, osmC was induced by ethanol and osmotic stress [3].

Analytical, diagnostic and therapeutic context of osmC

• The existence of these two promoters was confirmed by site-directed mutagenesis. osmC transcription is regulated by the growth phase [1].

References