Identification and characterization of starvation induced msdgc-1 promoter involved in the c-di-GMP turnover.
C-di-GMP [Bis-(3'-5')-cyclic-dimeric-guanosine monophosphate], a second messenger is involved in intracellular communication in the bacterial species. As a result several multi-cellular behaviors in both Gram-positive and Gram-negative bacteria are directly linked to the intracellular level of c-di-GMP. The cellular concentration of c-di-GMP is maintained by two opposing activities, diguanylate cyclase (DGC) and phosphodiesterase (PDE-A). In Mycobacterium smegmatis, a single bifunctional protein MSDGC-1 is responsible for the cellular concentration of c-di-GMP. A better understanding of the regulation of c-di-GMP at the genetic level is necessary to control the function of above two activities. In this work, we have characterized the promoter element present in msdgc-1 along with the +1 transcription start site and identified the sigma factors that regulate the transcription of msdgc-1. Interestingly, msdgc-1 utilizes SigA during the initial phase of growth, whereas near the stationary phase SigB containing RNA polymerase takes over the expression of msdgc-1. We report here that the promoter activity of msdgc-1 increases during starvation or depletion of carbon source like glucose or glycerol. When msdgc-1 is deleted, the numbers of viable cells are ~10 times higher in the stationary phase in comparison to that of the wild type. We propose here that msdgc-1 is involved in the regulation of cell population density.
Molecular Biophysics Unit, Indian Institute of Science, Bangalore 560012, India.
Binod K
BK
Bharati
R K
RK
Swetha
Dipankar
D
Chatterji
D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D001483:Base Sequence; D002874:Chromosome Mapping; D003470:Culture Media; D006152:Cyclic GMP / Q000031:analogs & derivatives; D004790:Enzyme Induction; D029968:Escherichia coli Proteins / Q000235:genetics* / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D055786:Gene Knockout Techniques; D017930:Genes, Reporter; D005947:Glucose / Q000502:physiology; D005990:Glycerol / Q000378:metabolism; D058977:Molecular Sequence Annotation; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D020102:Mycobacterium smegmatis / Q000201:enzymology / Q000235:genetics* / Q000254:growth & development; D019761:Phosphorus-Oxygen Lyases / Q000235:genetics* / Q000378:metabolism; D017354:Point Mutation; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D012808:Sigma Factor / Q000737:chemistry; D013312:Stress, Physiological; D024363:Transcription Initiation Site; D001616:beta-Galactosidase / Q000096:biosynthesis / Q000235:genetics
D001426:Bacterial Proteins; D003470:Culture Media; D029968:Escherichia coli Proteins; D012808:Sigma Factor; C062025:bis(3',5')-cyclic diguanylic acid; D001616:beta-Galactosidase; D019761:Phosphorus-Oxygen Lyases; C060720:diguanylate cyclase; D006152:Cyclic GMP; D005947:Glucose; D005990:Glycerol
7H9; BRIT; Board of Radiation and Isotope Technology; DGCCO; DGCKO; DGCKO complemented with MSMEG_2196; DGCOE; DMF; Dimethylformamide; EDTA; Ethylenedinitrilotetraacetic acid; MSMEG_2196 over expressing strain; Middlebrook-7H9; ONPG; PMSF; Phenylmethylsulfonyl fluoride; RelKO; Sigma factors; Transcription; c-di-GMP regulation; cfu; colony forming unit; deletion mutant of M. smegmatis rel gene; deletion mutant of MSMEG_2196; msdgc-1 promoter; o-nitrophenyl-β-d-galactopyranoside; β-Galactosidase