Browse
Submit Data
Databases
API
Help

Dataset Information

26 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

The DosS-DosT/DosR Mycobacterial Sensor System.

ABSTRACT: DosS/DosR is a two-component regulatory system in which DosS, a heme-containing sensor also known as DevS, under certain conditions undergoes autophosphorylation and then transfers the phosphate to DosR, a DNA-binding protein that controls the entry of Mycobacterium tuberculosis and other mycobacteria into a latent, dormant state. DosT, a second sensor closely related to DosS, is present in M. tuberculosis and participates in the control of the dormancy response mediated by DosR. The binding of phosphorylated DosR to DNA initiates the expression of approximately fifty dormancy-linked genes. DosT is accepted to be a gas sensor that is activated in the ferrous state by the absence of an oxygen ligand or by the binding of NO or CO. DosS functions in a similar fashion as a gas sensor, but contradictory evidence has led to the suggestion that it also functions as a redox state sensor. This review focuses on the structure, biophysical properties, and function of the DosS/DosT heme sensors.

SUBMITTER: Sivaramakrishnan S

PROVIDER: S-EPMC4082495 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Similar Datasets

Unique roles of DosT and DosS in DosR regulon induction and Mycobacterium tuberculosis dormancy.

Project description:In Mycobacterium tuberculosis, the sensor kinases DosT and DosS activate the transcriptional regulator DosR, resulting in the induction of the DosR regulon, which is important for anaerobic survival and perhaps latent infection. The individual and collective roles of these sensors have been postulated biochemically, but their roles in vivo have remained unclear. This work demonstrates distinct and additive roles for each sensor during anaerobic dormancy. Both sensors are necessary for wild-type levels of DosR regulon induction, and concomitantly, full induction of the regulon is required for wild-type anaerobic survival. In the anaerobic model, DosT plays an early role, responding to hypoxia. DosT then induces the regulon and with it DosS, which sustains and further induces the regulon. DosT then loses its functionality as oxygen becomes limited, and DosS alone maintains induction of the genes from that point forward. Thus, M. tuberculosis has evolved a system whereby it responds to hypoxic conditions in a stepwise fashion as it enters an anaerobic state.

| S-EPMC2715697 | biostudies-literature

Mycobacterium tuberculosis DosS is a redox sensor and DosT is a hypoxia sensor.

Project description:A fundamental challenge to the study of oxidative stress responses of Mycobacterium tuberculosis (Mtb) is to understand how the protective host molecules are sensed and relayed to control bacilli gene expression. The genetic response of Mtb to hypoxia and NO is controlled by the sensor kinases DosS and DosT and the response regulator DosR through activation of the dormancy/NO (Dos) regulon. However, the regulatory ligands of DosS and DosT and the mechanism of signal sensing were unknown. Here, we show that both DosS and DosT bind heme as a prosthetic group and that DosS is rapidly autooxidized to attain the met (Fe3+) form, whereas DosT exists in the O2-bound (oxy) form. EPR and UV-visible spectroscopy analysis showed that O2, NO, and CO are ligands of DosS and DosT. Importantly, we demonstrate that the oxidation or ligation state of the heme iron modulates DosS and DosT autokinase activity and that ferrous DosS, and deoxy DosT, show significantly increased autokinase activity compared with met DosS and oxy DosT. Our data provide direct proof that DosS functions as a redox sensor, whereas DosT functions as a hypoxia sensor, and that O2, NO, and CO are modulatory ligands of DosS and DosT. Finally, we identified a third potential dormancy signal, CO, that induces the Mtb Dos regulon. We conclude that Mtb has evolved finely tuned redox and hypoxia-mediated sensing strategies for detecting O2, NO, and CO. Data presented here establish a paradigm for understanding the mechanism of bacilli persistence.

| S-EPMC1906723 | biostudies-literature

Strains of the East Asian (W/Beijing) lineage of Mycobacterium tuberculosis are DosS/DosT-DosR two-component regulatory system natural mutants.

Project description:As part of our ongoing efforts to uncover the phenotypic consequences of genetic variability among clinical Mycobacterium tuberculosis isolates, we previously reported that isolates of the "East Asian" or "W/Beijing" lineage constitutively overexpress the coordinately regulated transcriptional program known as the DosR regulon under standard in vitro conditions. This phenotype distinguishes the W/Beijing lineage from all other M. tuberculosis lineages, which normally induce expression of this regulon only once exposed to low oxygen or nitric oxide, both of which result in inhibition of bacterial respiration and replication. Transcription of the DosR regulon is controlled through a two-component regulatory system comprising the transcription factor DosR and two possible cognate histidine sensor kinases, DosS and DosT. Through sequence analysis of a carefully selected set of isolates representing each of the major M. tuberculosis lineages, we describe herein a naturally occurring frameshift mutation in the gene encoding the DosT sensor kinase for isolates of the most recently evolved W/Beijing sublineages. Intriguingly, the occurrence of the frameshift mutation correlates precisely with the appearance of the constitutive DosR regulon phenotype displayed by the same "modern" W/Beijing strains. However, complementation studies have revealed that the mutation in dosT alone is not directly responsible for the constitutive DosR regulon phenotype. Our data serve to highlight the evolutionary pressure that exists among distinct M. tuberculosis lineages to maintain tight control over DosR regulon expression.

| S-EPMC2849454 | biostudies-literature

Mycobacterium tuberculosis sensor kinase DosS modulates the autophagosome in a DosR-independent manner.

Project description:Dormancy is a key characteristic of the intracellular life-cycle of Mtb. The importance of sensor kinase DosS in mycobacteria are attributed in part to our current findings that DosS is required for both persistence and full virulence of Mtb. Here we show that DosS is also required for optimal replication in macrophages and involved in the suppression of TNF-? and autophagy pathways. Silencing of these pathways during the infection process restored full virulence in Mtb?dosS mutant. Notably, a mutant of the response regulator DosR did not exhibit the attenuation in macrophages, suggesting that DosS can function independently of DosR. We identified four DosS targets in Mtb genome; Rv0440, Rv2859c, Rv0994, and Rv0260c. These genes encode functions related to hypoxia adaptation, which are not directly controlled by DosR, e.g., protein recycling and chaperoning, biosynthesis of molybdenum cofactor and nitrogen metabolism. Our results strongly suggest a DosR-independent role for DosS in Mtb.

| S-EPMC6754383 | biostudies-literature

The unique roles of DosT and DosS in DosR regulon induction and Mycobacterium tuberculosis dormancy

Project description:In Mycobacterium tuberculosis, the sensor kinases DosT and DosS activate the transcriptional regulator DosR, resulting in the induction of the DosR regulon, important for anaerobic survival and perhaps latent infection. The individual and collective roles of these sensors has been postulated biochemically, but their roles have remained unclear in vivo. This work demonstrates distinct and additive roles for each sensor during anaerobic dormancy. Both sensors are necessary for wild type levels of DosR regulon induction, and concomitantly, full induction of the regulon is required for wild type anaerobic survival. In the anaerobic model, DosT plays an early role, responding to hypoxia. DosT then induces the regulon and with it DosS, which sustains and further induces the regulon. DosT then loses its functionality as oxygen becomes limited, and DosS alone maintains induction of the genes from that point forward. Thus, M. tuberculosis has evolved a system whereby it responds to hypoxic conditions in a stepwise fashion as it enters an anaerobic state.

2009-06-26 | GSE16811 | GEO

Ultrafast ligand dynamics in the heme-based GAF sensor domains of the histidine kinases DosS and DosT from Mycobacterium tuberculosis.

Project description:The transcriptional regulator DosR from M. tuberculosis plays a crucial role in the virulence to dormancy transition of the pathogen. DosR can be activated by DosT and DosS, two histidine kinases with heme-containing sensor GAF domains, capable of diatomic ligand binding. To investigate the initial processes occurring upon ligand dissociation, we performed ultrafast time-resolved absorption spectroscopy of the isolated sensor domains ligated with O(2), NO, and CO. The results reveal a relatively closed heme pocket for both proteins. For DosT the yield of O(2) escape from the heme pocket on the picoseconds time scale upon photodissociation was found to be very low (1.5%), similar to other heme-based oxygen sensor proteins, implying that this sensor acts as an effective O(2) trap. Remarkably, this yield is an order of magnitude higher in DosS (18%). For CO, by contrast, the fraction of CO rebinding within the heme pocket is higher in DosS. Experiments with mutant DosT sensor domains and molecular dynamics simulations indicate an important role in ligand discrimination of the distal tyrosine, present in both proteins, which forms a hydrogen bond with heme-bound O(2). We conclude that despite their similarity, DosT and DosS display ligand-specific different primary dynamics during the initial phases of intraprotein signaling. The distal tyrosine, present in both proteins, plays an important role in these processes.

| S-EPMC3254832 | biostudies-literature

Mycobacterium tuberculosis Sensor Kinase DosS Modulates the Autophagosome in a DosR-independent Manner

Project description:This SuperSeries is composed of the SubSeries listed below.

2018-08-22 | GSE118869 | GEO

The unique roles of DosT and DosS in DosR regulon induction and Mycobacterium tuberculosis dormancy

Project description:In Mycobacterium tuberculosis, the sensor kinases DosT and DosS activate the transcriptional regulator DosR, resulting in the induction of the DosR regulon, important for anaerobic survival and perhaps latent infection. The individual and collective roles of these sensors has been postulated biochemically, but their roles have remained unclear in vivo. This work demonstrates distinct and additive roles for each sensor during anaerobic dormancy. Both sensors are necessary for wild type levels of DosR regulon induction, and concomitantly, full induction of the regulon is required for wild type anaerobic survival. In the anaerobic model, DosT plays an early role, responding to hypoxia. DosT then induces the regulon and with it DosS, which sustains and further induces the regulon. DosT then loses its functionality as oxygen becomes limited, and DosS alone maintains induction of the genes from that point forward. Thus, M. tuberculosis has evolved a system whereby it responds to hypoxic conditions in a stepwise fashion as it enters an anaerobic state. Various DosS and DosT mutant strains were analyzed against wild type (reference strain H37Rv, identical conditions as mutant) under various conditions: day 6 in an anaerobic dormancy model, 4 or 24 hours in a GasPak model, or log phase with the addition of a nitric oxide donor. Experiments were repeated in triplicate or quadruplicate.

2009-06-26 | E-GEOD-16811 | biostudies-arrayexpress

Mycobacterium tuberculosis Sensor Kinase DosS Modulates the Autophagosome in a DosR-independent Manner [II]

Project description:Transcriptional profiling of bacterial RNA samples from infected Rhesus Bone Marrow Derived Macrophages (RhBMDMs) compared to RNA isolated from respective in vitro grwon cultures viz M. tuberculosis H37Rv or Isogeneic mutant MtbdosS

2018-08-22 | GSE118867 | GEO

Mycobacterium tuberculosis Sensor Kinase DosS Modulates the Autophagosome in a DosR-independent Manner [I]

Project description:Transcriptional profiling of RNA samples from un-infected Rhesus Bone Marrow Derived Macrophages (RhBMDMs) exposed to IMDM complete media used as control were compared to RNA from RhBMDMs infected for 24 hr with 'dos' mutants of Mtb viz. MtbΔdosR, MtbΔdosS, or MtbΔdosT

2018-08-22 | GSE118866 | GEO

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data