Bacteria sense their environment using receptors of the histidine sensor kinase family, but how kinase activity is regulated by ligand binding is not well understood. Autoinducer-2 (AI-2), a secreted signaling molecule originally identified in studies of the marine bacterium Vibrio harveyi, regulates quorum-sensing responses and allows communication between different bacterial species. AI-2 signal transduction in V. harveyi requires the integral membrane receptor LuxPQ, comprised of periplasmic binding protein (LuxP) and histidine sensor kinase (LuxQ) subunits. Combined X-ray crystallographic and functional studies show that AI-2 binding causes a major conformational change within LuxP, which in turn stabilizes a quaternary arrangement in which two LuxPQ monomers are asymmetrically associated. We propose that formation of this asymmetric quaternary structure is responsible for repressing the kinase activity of both LuxQ subunits and triggering the transition of V. harveyi into quorum-sensing mode.

Download full-text PDF

Source
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3468944PMC
http://dx.doi.org/10.1016/j.cell.2006.07.032DOI Listing

Publication Analysis

Top Keywords

histidine sensor
12
sensor kinase
12
kinase activity
8
luxq subunits
8
kinase
5
ligand-induced asymmetry
4
asymmetry histidine
4
kinase complex
4
complex regulates
4
regulates quorum
4

Similar Publications

A Stable Zn(II) Metal-Organic Framework as Turn-On and Blue-Shift Fluorescence Sensor for Amino Acids and Dipicolinic Acid in Living Cells or Using Aerosol Jet Printing.

Inorg Chem

January 2025

School of Chemistry and Chemical Engineering, Jiangxi Provincial Key Laboratory of Functional Crystalline Materials Chemistry, Jiangxi University of Science and Technology, Ganzhou 341000, Jiangxi Province, P. R. China.

Amino acids and dipicolinic acid (DPA) are important biomarkers for identifying human health. Establishing rapid, accurate, sensitive, and simple assays is essential for disease prevention and early diagnosis. In this work, a novel Zn(II) metal-organic framework (MOF) with the formula {[Zn(μ-OH)(BTDI)(dpp)]·dpp·4HO·2DMF} (, where denotes Jiangxi University of Science and Technology, HBTDI = 5,5'-(benzo[][1,2,5]thiadiazole-4,7-diyl)diisophthalic acid; dpp = 1,3-di(4-pyridyl)propane) was successfully synthesized via a mixed-ligands strategy.

View Article and Find Full Text PDF

RcsF-independent mechanisms of signaling within the Rcs phosphorelay.

PLoS Genet

December 2024

Laboratory of Molecular Biology, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland, United States of America.

The Rcs (regulator of capsule synthesis) phosphorelay is a conserved cell envelope stress response mechanism in enterobacteria. It responds to perturbations at the cell surface and the peptidoglycan layer from a variety of sources, including antimicrobial peptides, beta-lactams, and changes in osmolarity. RcsF, an outer membrane lipoprotein, is the sensor for this pathway and activates the phosphorelay by interacting with an inner membrane protein IgaA.

View Article and Find Full Text PDF

Stress contingent changes in Hog1 pathway architecture and regulation in Candida albicans.

PLoS Pathog

December 2024

Newcastle University Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, United Kingdom.

The Hog1 stress-activated protein kinase (SAPK) is a key mediator of stress resistance and virulence in Candida albicans. Hog1 activation via phosphorylation of the canonical TGY motif is mediated by the Pbs2 MAPKK, which itself is activated by the Ssk2 MAPKKK. Although this three-tiered SAPK signalling module is well characterised, it is unclear how Hog1 activation is regulated in response to different stresses.

View Article and Find Full Text PDF

Plant growth depends on growth regulators, nutrient availability, and amino acids levels, all of which influence cell wall formation and cell expansion. Cell wall integrity and structures are surveyed and modified by a complex array of cell wall integrity sensors, including LRR-extensins (LRXs) that bind RALF (rapid alkalinization factor) peptides with high affinity and help to compact cell walls. Expressing the Arabidopsis root-hair specific LRX1 without the extensin domain, which anchors the protein to the cell wall, has a negative effect on root hair development.

View Article and Find Full Text PDF

This study aimed to develop a compensatory growth model using growing beef cattle by changing dietary protein and to investigate the underlying mechanisms of compensatory protein deposition in muscle tissue. Twelve Charolais bulls were randomly assigned to one of two groups with two periods: 1) a control group (CON) fed a 13% crude protein (CP) diet for 6 weeks; 2) a treatment group (REC) fed a 7% CP diet for 4 weeks (restriction period) and fed a 13% CP diet in the following 2 weeks (re-alimentation period). Growth performance, digestibility, nitrogen balance, targeted metabolomics of amino acids (AA) in plasma, and transcriptional profiling in muscle tissue were analyzed.

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!