Functional characterization of MarR family transcription factors in Chromobacterium violaceum

• Grant number: 13/25745-9
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: March 01, 2014
• End date: February 28, 2018
• Field of knowledge: Biological Sciences - Genetics - Molecular Genetics and Genetics of Microorganisms
• Principal Investigator: José Freire da Silva Neto
• Grantee: Maristela Previato Mello
• Host Institution: Faculdade de Medicina de Ribeirão Preto (FMRP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil
• Associated research grant: 12/20435-9 - Transcription factors of Chromobacterium violaceum: integrating signaling pathways, regulons and pathogenicity, AP.JP

Abstract

Gene expression can be modulated by transcription factors, which act directly as intracellular signal sensors or via signaling transduction pathways from the external environment. MarR family transcription factors, found in Bacteria and Archaea, act as direct sensors for different signals, controlling virulence, response to oxidative stress, antibiotic resistance and catabolic pathways. Although there are several potential MarR family transcription regulators in Chromobacterium violaceum, only OhrR, involved in resistance to organic hydroperoxides, has been previously studied by our lab. Therefore, we propose to identify and characterize MarR family transcription factors that control virulence in this human opportunistic pathogen, trying to elucidate the activation signals and the genes under regulation of each transcription factor. For this, we will identify the MarR family transcription factors in the genome of C. violaceum, classify them respect the presence of conserved cysteine residues and perform systematic mutagenesis for deletion of many genes encoding these regulators. The phenotype of each mutant strain will be characterized by testing for growth in many conditions and by virulence assays using a mouse model. The regulons of some of these transcription factors, mainly those involved in virulence, will be defined by DNA microarray analyses and by biochemical tests, such as DNA binding assays and site-directed mutagenesis of conserved cysteine residues. Thus, from this systematic analysis of MarR family transcription factors in C. violaceum, we intend to contribute to find novel bacterial virulence regulators.

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

ALVES, JULIA A.; PREVIATO-MELLO, MARISTELA; BARROSO, KELLY C. M.; KOIDE, TIE; DA SILVA NETO, JOSE F.. The MarR family regulator OsbR controls oxidative stress response, anaerobic nitrate respiration, and biofilm formation in Chromobacterium violaceum. BMC Microbiology, v. 21, n. 1, NOV 4 2021. (20/00259-8, 12/20435-9, 16/08728-1, 13/25745-9)

PREVIATO-MELLO, MARISTELA; MEIRELES, DIOGO DE ABREU; SOARES NETTO, LUIS EDUARDO; DA SILVA NETO, JOSE FREIRE. Global Transcriptional Response to Organic Hydroperoxide and the Role of OhrR in the Control of Virulence Traits in Chromobacterium violaceum. Infection and Immunity, v. 85, n. 8, AUG 2017. (13/25745-9, 12/21722-1, 12/20435-9)

BARROSO, KELLY C. M.; PREVIATO-MELLO, MARISTELA; BATISTA, BIANCA B.; BATISTA, JULIANA H.; DA SILVA NETO, JOSE F.. EmrR-Dependent Upregulation of the Efflux Pump EmrCAB Contributes to Antibiotic Resistance in Chromobacterium violaceum. FRONTIERS IN MICROBIOLOGY, v. 9, NOV 15 2018. (13/25745-9, 15/12605-0, 12/20435-9, 18/01388-6)

Academic Publications

(References retrieved automatically from State of São Paulo Research Institutions)

MELLO, Maristela Previato. Functional characterization of MarR family transcription factors in Chromobacterium violaceum. 2018. Doctoral Thesis - Universidade de São Paulo (USP). Faculdade de Medicina de Ribeirão Preto (PCARP/BC) Ribeirão Preto.