Characterization of the AtsR hybrid sensor kinase phosphorelay pathway and identification of its response regulator in Burkholderia cenocepacia.

J Biol Chem

From the Centre for Human Immunology, Department of Microbiology and Immunology, Schulich School of Medicine, University of Western Ontario, London, Ontario N6A 5C1, Canada and; the Centre for Infection and Immunity, Queen's University Belfast, BT9 5GZ Belfast, United Kingdom. Electronic address:

Published: October 2013

AtsR is a membrane-bound hybrid sensor kinase of Burkholderia cenocepacia that negatively regulates quorum sensing and virulence factors such as biofilm production, type 6-secretion, and protease secretion. Here we elucidate the mechanism of AtsR phosphorelay by site-directed mutagenesis of predicted histidine and aspartic acid phosphoacceptor residues. We demonstrate by in vitro phosphorylation that histidine 245 and aspartic acid 536 are conserved sites of phosphorylation in AtsR, and we also identify the cytosolic response regulator AtsT (BCAM0381) as a key component of the AtsR phosphorelay pathway. Monitoring the function of AtsR and its derivatives in vivo by measuring extracellular protease activity and swarming motility confirmed the in vitro phosphorylation results. Together we find that the AtsR receiver domain plays a fine-tuning role in determining the levels of phosphotransfer from its sensor kinase domain to the AtsT response regulator.

Download full-text PDF

Source
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3798511PMC
http://dx.doi.org/10.1074/jbc.M113.489914DOI Listing

Publication Analysis

Top Keywords

sensor kinase
12
response regulator
12
hybrid sensor
8
phosphorelay pathway
8
burkholderia cenocepacia
8
atsr phosphorelay
8
aspartic acid
8
vitro phosphorylation
8
atsr
6
characterization atsr
4

Similar Publications

Membrane bound histidine kinases (HKs) are ubiquitous sensors of extracellular stimuli in bacteria. However, a uniform structural model is still missing for their transmembrane signaling mechanism. Here, we used solid-state NMR in conjunction with crystallography, solution NMR and distance measurements to investigate the transmembrane signaling mechanism of a paradigmatic citrate sensing membrane embedded HK, CitA.

View Article and Find Full Text PDF

Live imaging of paracrine signaling: Advances in visualization and tracking techniques.

Cell Struct Funct

January 2025

Department of Pathology and Biology of Diseases, Graduate School of Medicine, Kyoto University.

Live imaging techniques have revolutionized our understanding of paracrine signaling, a crucial form of cell-to-cell communication in biological processes. This review examines recent advances in visualizing and tracking paracrine factors through four key stages: secretion from producing cells, diffusion through extracellular space, binding to target cells, and activation of intracellular signaling within target cells. Paracrine factor secretion can be directly visualized by fluorescent protein tagging to ligand, or indirectly by visualizing the cleavage of the transmembrane pro-ligands or plasma membrane fusion of endosomes comprising the paracrine factors.

View Article and Find Full Text PDF

Rifampicin-resistant tuberculosis (RR-TB) is a critical issue with significant implications for patient care, public health, and TB control efforts that necessitate comprehensive strategies for detection. This study presents a novel point-of-care diagnostic tool for RR-TB detection employing a peptide nucleic acid (PNA)-paper-based sensor combined with isothermal recombinase polymerase amplification (RPA). The sensor targets mutations in codons 516, 526, and 531 of the rpoB gene, the top three common mutations associated with rifampicin-resistant strains.

View Article and Find Full Text PDF

Cytotoxic DNAs, methylation, histones and histones binding proteins are speculated to induce DNA sensors. Under stressed condition, the antigenic patterns, PAMPs and DAMPs, trigger the hyperactive innate response through DNA, DNA-RNA hybrids, oligonucleotides, histones and mtDNA to initiate cGAMP-STING-IFN I cascade. HSV -1&2, HIV, Varicella- Zoster virus, Polyomavirus, Cytomegalovirus, and KSHV negatively regulate the STING-MAVS-TBK-1/1KKE pathway.

View Article and Find Full Text PDF

Feedback loop centered on MAF1 reduces blood-brain barrier damage in sepsis-associated encephalopathy.

Cell Mol Biol Lett

January 2025

Department of Critical Care Medicine, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Southern Medical University, Guangzhou, China.

Background: A previous study found that MAF1 homolog, a negative regulator of RNA polymerase III (MAF1), protects the blood-brain barrier (BBB) in sepsis-associated encephalopathy (SAE); however, the related molecular mechanisms remain unclear.

Subjects And Methods: In this study, a rat sepsis model was constructed using the cecum ligation and puncture (CLP) method. In vitro, rat brain microvascular endothelial cells and astrocytes were stimulated with serum from the sepsis model rats.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!