DevR is a transcriptional regulator that mediates the genetic response of Mycobacterium tuberculosis to oxygen limitation and nitric oxide exposure. devR is co-transcribed along with devS, which encodes its cognate sensor kinase, and an upstream gene, Rv3134c. The transcriptional activity of this operon was characterized by primer extension, transcriptional fusion and electrophoretic mobility shift assays (EMSAs) under aerobic conditions. Transcription start points (Tsps) were detected upstream of both Rv3134c and devR, and the major transcript was derived from upstream of Rv3134c. Sequences with similarity to sigma factor consensus elements and to DevR-binding motifs were detected in the vicinity of the Tsps by in silico analysis. EMSAs with promoter regions and DevR protein showed that DevR binds to its own promoters in a sequence-specific manner with differing affinities. Consistent with the primer extension and EMSA data, Rv3134c promoters, and not devR promoters, were determined to be the principal promoters of this operon using reporter assays performed in Mycobacterium smegmatis and Escherichia coli. Furthermore, DevR modulated the activity of both devR and Rv3134c promoters. From these findings it is inferred that the Rv3134c-devR-devS operon is transcribed from multiple promoters and is autoregulated.
BashyamM. D.,
KaushalD.,
DasguptaS. K.,
TyagiA. K.
1996; A study of mycobacterial transcriptional apparatus: identification of novel features in promoter elements. J Bacteriol 178:4847–4853
CalamitaH.,
KoC.,
TyagiS.,
YoshimatsuT.,
MorrisonN. E.,
BishaiW. R.
2005; The Mycobacterium tuberculosis SigD sigma factor controls the expression of ribosome-associated gene products in stationary phase and is required for full virulence. Cell Microbiol 7:233–244
ColeS. T.,
BroschR.,
ParkhillJ.39 other authors1998; Deciphering the biology of Mycobacterium tuberculosis from the complete genome sequence. Nature 393:537–544[CrossRef]
Das GuptaS. K.,
BashyamM. D.,
TyagiA. K.
1993; Cloning and assessment of mycobacterial promoters by using a plasmid shuttle vector. J Bacteriol 175:5186–5192
DasguptaN.,
TyagiJ. S.
1998; Identification of a restriction fragment length polymorphism associated with a deletion that maps in a transcriptionally active open-reading frame, orfX , in Mycobacterium tuberculosis Erdman. Tuber Lung Dis 79:75–81[CrossRef]
DasguptaN.,
KapurV.,
SinghK. K.,
DasT. K.,
SachdevaS.,
JyothisriK.,
TyagiJ. S.
2000; Characterization of a two-component system, devR-devS , of Mycobacterium tuberculosis
. Tuber Lung Dis 80:141–159[CrossRef]
FlorczykM. A.,
McCueL. A.,
PurkayasthaA.,
CurrentiE.,
WolinM. J.,
McDonoughK. A.
2003; A family of acr -coregulated Mycobacterium tuberculosis genes shares a common DNA motif and requires Rv3133c ( dosR or devR ) for expression. Infect Immun 71:5332–5343[CrossRef]
HaydelS. E.,
BenjaminW. H.,
DunlapN. E.,
Clark-CurtissJ. EJr.
2002; Expression, autoregulation, and DNA binding properties of the Mycobacterium tuberculosis TrcR response regulator. J Bacteriol 184:2192–2203[CrossRef]
HeH.,
ZahrtT. C.
2005; Identification and characterization of a regulatory sequence recognized by Mycobacterium tuberculosis persistence regulator MprA. J Bacteriol 187:202–212[CrossRef]
HuY.,
CoatesA. R.
2001; Increased levels of sigJ mRNA in late stationary phase cultures of Mycobacterium tuberculosis detected by DNA array hybridisation. FEMS Microbiol Lett 202:59–65[CrossRef]
KingerA. K.,
TyagiJ. S.
1993; Identification and cloning of genes differentially expressed in the virulent strain of Mycobacterium tuberculosis
. Gene 131:113–117[CrossRef]
MalhotraV.,
SharmaD.,
RamanathanV. D.
& 8 other authors; 2004; Disruption of response regulator gene, devR , leads to attenuation in virulence of Mycobacterium tuberculosis
. FEMS Microbiol Lett 231:237–245[CrossRef]
NathanC.,
ShilohM. U.
2000; Reactive oxygen and nitrogen intermediates in the relationship between mammalian hosts and microbial pathogens. Proc Natl Acad Sci U S A 97:8841–8848[CrossRef]
NystromT.,
NeidhardtF. C.
1992; Cloning, mapping and nucleotide sequencing of a gene encoding a universal stress protein in Escherichia coli
. Mol Microbiol 6:3187–3198[CrossRef]
NystromT.,
NeidhardtF. C.
1994; Expression and role of the universal stress protein, UspA, of Escherichia coli during growth arrest. Mol Microbiol 11:537–544[CrossRef]
ParishT.,
SmithD. A.,
KendallS.,
CasaliN.,
BancroftG. J.,
StokerN. G.
2003; Deletion of two-component regulatory systems increases the virulence of Mycobacterium tuberculosis
. Infect Immun 71:1134–1140[CrossRef]
ParkH. D.,
GuinnK. M.,
HarrellM. I.,
LiaoR.,
VoskuilM. I.,
TompaM.,
SchoolnikG. K.,
ShermanD. R.
2003; Rv3133c/ dosR is a transcription factor that mediates the hypoxic response of Mycobacterium tuberculosis
. Mol Microbiol 48:833–843[CrossRef]
PaulS.,
BirkeyS.,
LiuW.,
HulettF. M.
2004; Autoinduction of Bacillus subtilis phoPR operon transcription results from enhanced transcription from E σ A- and E σ E-responsive promoters by phosphorylated PhoP. J Bacteriol 186:4262–4275[CrossRef]
RamanS.,
HazraR.,
DascherC. C.,
HussonR. N.
2004; Transcription regulation by the Mycobacterium tuberculosis alternative sigma factor SigD and its role in virulence. J Bacteriol 186:6605–6616[CrossRef]
RobertsD. M.,
LiaoR. P.,
WisedchaisriG.,
HolW. G.,
ShermanD. R.
2004; Two sensor kinases contribute to the hypoxic response of Mycobacterium tuberculosis
. J Biol Chem 279:23082–23087[CrossRef]
SainiD. K.,
MalhotraV.,
DeyD.,
PantN.,
DasT. K.,
TyagiJ. S.
2004; DevR-DevS is a bona fide two-component system of Mycobacterium tuberculosis that is hypoxia-responsive in the absence of the DNA-binding domain of DevR. Microbiology 150:865–875[CrossRef]
ScarlatoV.,
PrugnolaA.,
AricoB.,
RappuoliR.
1990; Positive transcriptional feedback at the bvg locus controls expression of virulence factors in Bordetella pertussis
. Proc Natl Acad Sci U S A 87:6753–6757[CrossRef]
TaborS.,
RichardsonC. C.
1985; A bacteriophage T7 RNA polymerase/promoter system for controlled exclusive expression of specific genes. Proc Natl Acad Sci U S A 82:1074–1078[CrossRef]
ValdiviaR. H.,
HromockyjA. E.,
MonackD.,
RamakrishnanL.,
FalkowS.
1996; Applications for green fluorescent protein (GFP) in the study of host-pathogen interactions. Gene 173:47–52[CrossRef]
VoskuilM. I.,
SchnappingerD.,
ViscontiK. C.,
HarrellM. I.,
DolganovG. M.,
ShermanD. R.,
SchoolnikG. K.
2003; Inhibition of respiration by nitric oxide induces a Mycobacterium tuberculosis dormancy program. J Exp Med 198:705–713[CrossRef]