Related Experiment Video
Updated: May 12, 2026
10:57
NF-κB-dependent Luciferase Activation and Quantification of Gene Expression in Salmonella Infected Tissue Culture Cells
Published on: January 12, 2020
GidA expression in Salmonella is modulated under certain environmental conditions
Jaclyn M Rehl1, Daniel C Shippy, Nicholas M Eakley
1Department of Animal Sciences, University of Wisconsin-Madison, 1675 Observatory Drive, Madison, WI 53706, USA.
Current Microbiology
|April 13, 2013
Summary
Glucose-inhibited division (GidA) protein levels increase in Salmonella under various environmental conditions. This GidA upregulation correlates with enhanced Salmonella virulence, suggesting a regulatory role in infection.
Area of Science:
- Microbiology
- Bacterial Pathogenesis
- Molecular Biology
Background:
- Glucose-inhibited division (GidA) protein is conserved across bacteria and eukarya.
- Previous studies showed GidA deficiency attenuates Salmonella virulence and reduces virulence gene expression.
Purpose of the Study:
- To investigate the impact of environmental factors (glucose, EDTA, pH 5) on GidA expression in Salmonella.
- To determine the relationship between GidA expression levels and Salmonella virulence under these conditions.
Main Methods:
- Transcriptional analysis using real-time RT-PCR and β-galactosidase assays.
- Protein expression analysis via semiquantitative Western blot.
- In vitro virulence assays for Salmonella.
Main Results:
- No significant changes in gidA transcription or promoter activity were observed under tested environmental conditions.
- Semiquantitative Western blot revealed a significant increase in GidA protein levels in Salmonella grown in different environments.
- Increased GidA expression correlated with enhanced Salmonella in vitro virulence.
Conclusions:
- Salmonella GidA protein expression is modulated by environmental conditions, independent of transcriptional changes.
- Elevated GidA levels are associated with increased Salmonella virulence potential in vitro.
- GidA plays a role in regulating Salmonella virulence in response to environmental cues.
Related Concept Videos
01:23Stringent Response in E. coli
Bacterial growth is closely tied to nutrient availability, with cells proliferating exponentially under favorable conditions and entering a stationary phase when resources become scarce. This transition is mediated by a regulatory mechanism known as the stringent response, which allows bacteria to adapt to nutrient deprivation by modulating gene expression and metabolic activity.During nutrient scarcity, intracellular amino acid levels decline. It results in the accumulation of uncharged tRNAs...
01:28Global Regulatory Systems
Global regulatory systems in bacteria enable rapid and coordinated responses to environmental changes by integrating sensory inputs with gene expression, ensuring efficient adaptation to fluctuating conditions. Key global regulatory mechanisms include regulons, two-component systems, sigma factors, and secondary messengers.Regulons and Global RegulatorsA regulon is a collection of genes and operons controlled by a common global regulator. These regulators enable bacteria to prioritize resource...
01:28Gene Regulation in Microbial Communities: Quorum Sensing
Quorum sensing is a mechanism of bacterial communication that enables coordinated gene expression in response to changes in population density. This facilitates collective behaviors that enhance survival, resource acquisition, and ecological adaptation. This process relies on small signaling molecules called autoinducers that accumulate as bacterial populations grow. When a critical threshold concentration of autoinducers is reached, bacterial cells collectively modify gene expression,...
01:17Gene Regulation During Sporulation
Sporulation is a complex developmental process that allows certain Gram-positive bacteria, such as Bacillus subtilis and Clostridium species, to survive extreme environmental conditions. This process is tightly regulated by a series of signaling cascades and transcriptional controls, ensuring the formation of a highly resistant endospore.Sporulation is triggered by unfavorable conditions, such as nutrient depletion, and is governed by a phosphorelay system. One of the sensor kinases, such as...
01:27Constitutive and Regulated Gene Expression
Gene expression in prokaryotes is governed by constitutive and regulated systems, allowing cells to balance the production of essential proteins with adaptive responses to environmental changes.Constitutive Gene ExpressionConstitutive, or housekeeping, genes are continuously expressed as they encode proteins vital for fundamental cellular processes. These include enzymes for glycolysis, ribosomal components for protein synthesis, and proteins involved in DNA replication. Their constant...
02:11Reporter Genes
Reporter genes are a type of protein-coding gene that are often tagged to a gene of interest. Once inside a target cell, reporter genes usually produce visually identifiable characteristics like fluorescence and luminescence when expressed along with the gene of interest. Thus, reporter genes “report” the presence or absence of genes of interest in an organism, determine the gene expression pattern, or track the physical location of a DNA segment or protein in the cell.
Commonly used reporter...
Commonly used reporter...