The genes zntA and zntR encoding a P-type ATPase and its activator confer zinc and cadmium resistance in Chromobacterium violaceum

Article Article scientifique Article The genes zntA and zntR encoding a P-type ATPase and its activator confer zinc and cadmium resistance in Chromobacterium violaceum eng 2026-05-22 2026-05-22 author Schuindt Carolina Panosso Departamento de Biologia Celular e Molecular e Bioagentes Patogênicos, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil. author Batista Bianca Bontempi Departamento de Biologia Celular e Molecular e Bioagentes Patogênicos, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil. author De Moraes Ceseti Lucas Department of Biochemistry, University of Geneva, Sciences II, Geneva-4, CH-1211, Geneva, Switzerland. 979133 Biochimie groupe 8 (CHIB8) author Lima Neto Sergio Pereira Departamento de Biologia Celular e Molecular e Bioagentes Patogênicos, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil. author Soldati Thierry 0000-0002-2056-7931 Department of Biochemistry, University of Geneva, Sciences II, Geneva-4, CH-1211, Geneva, Switzerland. 135632 Département de biochimie (CHIBI) author da Silva Neto José Freire Departamento de Biologia Celular e Molecular e Bioagentes Patogênicos, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil. jfsneto@usp.br. 10.1007/s10534-026-00828-4 42174353 0966-0844 https://link.springer.com/article/10.1007/s10534-026-00828-4 The transition metal zinc is an essential trace element for life but becomes toxic at high concentrations. In the opportunistic pathogen Chromobacterium violaceum, zinc acquisition is crucial for virulence, yet how this bacterium copes with zinc toxicity remains unknown. In this work, we demonstrate that C. violaceum senses and responds to excess zinc by activating the zntA gene, which encodes a P1B-2 -type ATPase, via the transcriptional regulator ZntR. Phenotypic analyses by growth curves, disk diffusion, and CFU assays revealed that both ΔzntA or ΔzntR mutant strains exhibited increased sensitivity to zinc and cadmium. The ΔzntA mutant showed increased zinc and cadmium accumulation, suggesting that ZntA functions as an efflux pump. The expression of zntA increased in the presence of zinc and cadmium in the wild-type strain, but not in the ΔzntR mutant strain, indicating that ZntR activates zntA under conditions of zinc or cadmium excess. The role of ZntA in vivo was analyzed using the social amoeba Dictyostelium discoideum as a host cell. Plaque assays indicated that the C. violaceum ΔzntA mutant strain was more susceptible than the C. violaceum wild-type strain to clearance by D. discoideum knockout strains with altered intracellular zinc allocation. Overall, our data reveal that the genes zntA and zntR encoding a P1B-2 -type ATPase and its transcriptional activator are key determinants of zinc and cadmium resistance in C. violaceum, ensuring bacterial survival under zinc-stress conditions encountered in the environment and the host. Chromobacterium violaceum Cadmium resistance Efflux pump Metal toxicity Transcription factor Zinc resistance Dewey 540 São Paulo Research Foundation (FAPESP) 2021/06894–0 São Paulo Research Foundation (FAPESP) 2021/10577–0 Swiss National Science Foundation Molecular mechanisms of the Xanthomonas citri resistance to Dictyostelium discoideum predation and the role of the Type VI Secretion System 213739 CH 39 Département de biochimie 144 false 766 Groupe Soldati BioMetals 39 3 75ae4160-9b00-465d-b8ad-0acb5934bdd4 Article (Published version) Public Schuindt_et_al26.pdf 6505322 application/pdf CC BY-4.0 d77079ddd7eb3fc27d2b1573563083386f3ce20565e7a3ffba46ca0f3f1c949c openAccess Faculté des sciences / Section de chimie et biochimie / Département de biochimie

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The genes zntA and zntR encoding a P-type ATPase and its activator confer zinc and cadmium resistance in Chromobacterium violaceum	BioMetals			2026	4	6

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De Moraes Ceseti, Lucas