The combined actions of the copper-responsive repressor CsoR and copper-metallochaperone CopZ modulate CopA-mediated copper efflux in the intracellular pathogen Listeria monocytogenes Original paper
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Divine Aleru
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Divine Aleru
Read MoreI am a biochemist with a deep curiosity for the human microbiome and how it shapes human health, and I enjoy making microbiome science more accessible through research and writing. With 2 years experience in microbiome research, I have curated microbiome studies, analyzed microbial signatures, and now focus on interventions as a Microbiome Signatures and Interventions Research Coordinator.
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Microbes
Microbes
Microbes are microscopic organisms living in and on the human body, shaping health through digestion, vitamin production, and immune protection. When microbial balance is disrupted, disease can occur. This guide explains key microbe types—bacteria, viruses, fungi, protozoa, and archaea—plus major pathogenic and beneficial examples.
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Divine Aleru
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Researched by:
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Divine Aleru
ID
Divine Aleru
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Microbiome Signatures identifies and validates condition-specific microbiome shifts and interventions to accelerate clinical translation. Our multidisciplinary team supports clinicians, researchers, and innovators in turning microbiome science into actionable medicine.
Divine Aleru
What was studied?
This study investigated the copper resistance mechanisms in Listeria monocytogenes, particularly focusing on the copper-responsive operon csoR-copA-copZ. It examined the role of CsoR, a copper-sensing transcriptional repressor, in regulating the operon and how CopA, a copper-exporting ATPase, helps Listeria resist copper toxicity. The researchers also explored the regulatory functions of CopZ, a copper metallochaperone, in the operon’s expression.
Who was studied?
Listeria monocytogenes was the primary organism studied, specifically its copper resistance operon. The research involved creating mutants of Listeria monocytogenes that lacked certain genes (csoR, copA, copZ) and assessing their responses to copper exposure. Both wild-type and mutant strains were analyzed in vitro for copper sensitivity, copper accumulation, and operon regulation.
What were the most important findings?
The study confirmed that the csoR-copA-copZ operon in Listeria monocytogenes is specifically induced by elevated copper levels. CsoR, a copper-sensing transcriptional repressor, regulates this operon by binding to the promoter region of copA. The presence of copper derepresses the operon, allowing for the expression of CopA, which acts as a copper efflux pump to expel excess copper from the bacterium. In mutants lacking CopA, Listeria was highly sensitive to copper and accumulated excessive amounts. The role of CopZ was also explored, revealing that CopZ does not directly deliver copper to CsoR, but rather, it modulates CsoR’s access to copper, thus tempering the transcriptional response to copper exposure. Additionally, it was discovered that CopZ did not significantly affect copper tolerance but helped regulate the transcription of the operon in response to copper levels.
What are the greatest implications of this study?
The findings underscore the critical role of copper homeostasis in Listeria monocytogenes and its ability to resist copper toxicity during infection. Understanding how Listeria manages copper stress could inform therapeutic strategies targeting bacterial resistance to copper, which is particularly relevant in environments where copper is used as an antimicrobial agent. The study also provides insight into bacterial adaptation mechanisms to host-imposed copper stress, which could lead to the development of novel drugs targeting copper resistance systems in pathogens.
Listeria monocytogenes
Listeria monocytogenes is an opportunistic pathogen capable of surviving in diverse environments, including soil, water, and decaying vegetation. L. monocytogenes has the unique ability to evade the immune system by moving directly from cell to cell within the host. This intracellular lifestyle allows the bacterium to avoid extracellular immune detection, contributing to its ability to cause invasive diseases like meningitis and septicemia, particularly in the elderly and immunocompromised.