Autoinduction is a conserved mechanism of cell density-dependent gene regulation that occurs in a variety of gram-negative bacteria. Autoinducible luminescence in Vibrio fischeri requires a transcriptional activator, LuxR, while a LuxR homolog, LasR, activates elastase expression in Pseudomonas aeruginosa. Both LuxR and LasR require specific signal molecules, called autoinducers, for activity. We show here the activation in Escherichia coli of the V. fischeri luminescence (lux) operon by LasR and of the P. aeruginosa elastase gene (lasB) by LuxR when each is in the presence of its cognate autoinducer. Neither LuxR nor LasR showed appreciable activity with the heterologous V. fischeri or P. aeruginosa autoinducer. This supports the view that there is a direct interaction of each transcriptional activator with its proper autoinducer and suggests that there are conserved, autoinduction-related elements within the promoter regions of these genes.
Download full-text PDF |
Source |
|---|---|
| http://www.ncbi.nlm.nih.gov/pmc/articles/PMC205467 | PMC |
| http://dx.doi.org/10.1128/jb.176.10.3076-3080.1994 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
LitR and its quorum-sensing regulators modulate biofilm formation by .
J Bacteriol
January 2025
Department of Microbiology and Immunology, Stritch School of Medicine Loyola University Chicago, Chicago, Illinois, USA.
Quorum sensing controls numerous processes ranging from the production of virulence factors to biofilm formation. Biofilms, communities of bacteria that are attached to one another and/or a surface, are common in nature, and when they form, they can produce a quorum of bacteria. One model system to study biofilms is the bacterium , which forms a biofilm that promotes the colonization of its symbiotic host.
View Article and Find Full Text PDFOptimization of Toxicity, Biodegradability, and Skin Irritation in Formulations Containing Mixtures of Anionic and Nonionic Surfactants Combined with Silica Nanoparticles.
Toxics
January 2025
Department of Chemical Engineering, Faculty of Sciences, University of Granada, Campus Fuente Nueva s/n, 18071 Granada, Spain.
Surfactants play a crucial role in various industrial applications, including detergents and personal care products. However, their widespread use raises concerns due to their potential environmental impact and health risks, particularly in aquatic ecosystems, where they can disrupt the balance of marine life and accumulate in water sources, posing challenges to sustainable development. This study investigates the environmental and health implications of anionic and nonionic surfactants, focusing on their toxicity, biodegradation, and skin irritation potential profiles, especially when combined with silica nanoparticles.
View Article and Find Full Text PDFThe conserved global regulator H-NS has a strain-specific impact on biofilm formation in symbionts.
bioRxiv
December 2024
Earth, Marine & Environmental Sciences Department, University of North Carolina, Chapel Hill, NC.
Unlabelled: Strain-level variation among host-associated bacteria often determines host range and the extent to which colonization is beneficial, benign, or pathogenic. is a beneficial symbiont of the light organs of fish and squid with known strain-specific differences that impact host specificity, colonization efficiency, and interbacterial competition. Here, we describe how the conserved global regulator, H-NS, has a strain-specific impact on a critical colonization behavior: biofilm formation.
View Article and Find Full Text PDFA mutualistic model bacterium is lethal to non-symbiotic hosts via the type VI secretion system.
bioRxiv
December 2024
Department of Biochemistry and Molecular Biology, Brody School of Medicine, East Carolina University.
What makes a bacterium pathogenic? Since the early days of germ theory, researchers have categorized bacteria as pathogens or non-pathogens, those that cause harm and those that do not, but this binary view is not always accurate. is an exclusive mutualistic symbiont found within the light organs of Hawaiian bobtail squid. This symbiotic interaction requires to utilize a range of behaviors and produce molecules that are often associated with pathogenicity.
View Article and Find Full Text PDFDistinct baseline toxicity of volatile organic compounds (VOCs) in gaseous and liquid phases: Mixture effects and potential molecular mechanisms.
J Hazard Mater
December 2024
Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP3), Department of Environmental Science and Engineering, Fudan University, Shanghai 200438, China.
Volatile organic compounds (VOCs) are significant pollutants found in various environments, posing health risks. Traditionally, the gaseous VOCs are adsorbed and eluted in liquid phases, and then subjected to toxicity testing, which deviates from the actual exposure scenarios of gaseous VOCs. How the physical states of VOCs (gaseous or liquid) affect their toxicity has not been well understood.
View Article and Find Full Text PDFWant 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!