Related Experiment Video

Updated: Dec 13, 2025

Quantification of Cytosolic vs. Vacuolar Salmonella in Primary Macrophages by Differential Permeabilization
09:25

Quantification of Cytosolic vs. Vacuolar Salmonella in Primary Macrophages by Differential Permeabilization

Published on: July 28, 2015

11.2K

Small proteins regulate Salmonella survival inside macrophages by controlling degradation of a magnesium transporter

Jinki Yeom1,2,3, Yi Shao1, Eduardo A Groisman4,5

  • 1Department of Microbial Pathogenesis, Yale School of Medicine, New Haven, CT 06536.

Proceedings of the National Academy of Sciences of the United States of America
|August 6, 2020
PubMed

Insights

Salmonella uses small proteins to control magnesium transporter MgtB levels. MgtR promotes MgtB degradation, while MgtU prevents it, ensuring pathogen survival in macrophages.

Area of Science:

  • Microbiology
  • Molecular Biology
  • Host-Pathogen Interactions

Background:

  • Magnesium (Mg2+) is essential for cell replication and proliferation.
  • The macrophage protein Slc11a1 limits microbial invasion by inducing Mg2+ starvation.
  • Salmonella enterica serovar Typhimurium utilizes the Mg2+ transporter MgtB to cause disease in mice with functional Slc11a1.

Purpose of the Study:

  • To investigate how Salmonella preserves MgtB for survival within macrophages.
  • To identify the regulatory mechanisms controlling MgtB abundance in Salmonella.

Main Methods:

  • Investigated the roles of small proteins MgtR and MgtU in regulating MgtB stability.
  • Utilized genetic manipulation and proteolysis assays.
  • Examined MgtB and MgtA transporter regulation.

Main Results:

  • Salmonella small protein MgtR promotes MgtB degradation via the FtsH protease.
  • Small protein MgtU prevents MgtB proteolysis, even in the absence of MgtR.
  • MgtU is crucial for Salmonella survival in Slc11a1+/+ macrophages, oxidative stress resistance, and growth under Mg2+ limitation.
  • MgtU does not protect the related MgtA transporter from degradation.

Conclusions:

  • Small proteins MgtR and MgtU dynamically regulate the abundance of the MgtB Mg2+ transporter.
  • This regulation is critical for Salmonella survival within host macrophages.
  • The mgtB, mgtR, and mgtU genes form a single transcript, allowing coordinated control of MgtB levels.
  • Small proteins can modulate transporter abundance to ensure pathogen homeostasis and survival.
Keywords:
FtsHMgtBMgtRMgtUproteolysis

More Related Videos

A Non-Coding Small RNA MicC Contributes to Virulence in Outer Membrane Proteins in Salmonella Enteritidis06:30

A Non-Coding Small RNA MicC Contributes to Virulence in Outer Membrane Proteins in Salmonella Enteritidis

Published on: January 27, 2021

2.0K
Isolation of Salmonella typhimurium-containing Phagosomes from Macrophages10:33

Isolation of Salmonella typhimurium-containing Phagosomes from Macrophages

Published on: October 25, 2017

11.0K

Related Concept Videos

Translational Regulation01:29

Translational Regulation

Translational regulation in prokaryotes ensures efficient protein synthesis by controlling ribosome access to mRNA. This regulation is mediated by secondary RNA structures, including translational riboswitches, RNA thermometers, and small RNAs (sRNAs), which respond to intracellular and environmental signals to modulate gene expression.Translational RiboswitchesRiboswitches in the leader region of mRNAs can regulate translation by altering the accessibility of the Shine-Dalgarno (SD) sequence,...
425
Stringent Response in E. coli01:23

Stringent 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...
199
Other Stress Responses in Bacteria01:30

Other Stress Responses in Bacteria

Bacteria have global regulatory systems that control several types of stress mechanisms. These include Pho regulon and the heat shock response, which are essential systems for environmental adaptation, such as nutrient limitation and proteotoxic stress. The Pho regulon and the heat shock response exemplify bacterial resilience, enabling rapid adaptation to fluctuating environmental conditions.Pho RegulonBacteria require phosphorus for essential cellular processes, including nucleic acid...
248
Gene Regulation in Microbial Communities: Quorum Sensing01:28

Gene 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,...
363
Global Regulatory Systems01:28

Global 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...
417
Regulation of Nuclear Protein Sorting01:45

Regulation of Nuclear Protein Sorting

Nuclear protein sorting regulates nucleus composition and gene expression, crucial for determining the fate of a eukaryotic cell. Hence, the entry and exit of molecules across the nuclear envelope is a tightly controlled process. Nuclear protein sorting can be inhibited by one of the following ways: 1) masking cargo signal sequences, 2) modifying the nuclear receptor's affinity for cargo, 3) controlling the nuclear pore size, 4) retaining the cargo during its transit to the cytosol or the...
3.1K