Mechanisms of heme uptake in Chromobacterium violaceum

• Grant number: 18/17716-2
• Support Opportunities: Scholarships in Brazil - Master
• Start date: December 01, 2018
• End date: August 31, 2020
• Field of knowledge: Biological Sciences - Genetics - Molecular Genetics and Genetics of Microorganisms
• Agreement: Coordination of Improvement of Higher Education Personnel (CAPES)
• Principal Investigator: José Freire da Silva Neto
• Grantee: Vinicius Marques de Lima
• Host Institution: Faculdade de Medicina de Ribeirão Preto (FMRP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil

Abstract

Iron is an important metal in several cellular processes and it is found in high amounts in the heme group of hemoproteins, like hemoglobin. To exploit this abundant source of iron in the host many pathogens have heme uptake and degradation mechanisms. In this work we aim to identify these mechanisms in the bacterium Chromobacterium violaceum, a Gram-negative beta-proteobacterium found in soil and water of tropical regions, that causes severe opportunistic infections in humans. In silico analysis of C. violaceum ATCC 12472 genome revealed the chuPRSTUV operon as a candidate to encode a heme uptake and degradation system. To characterize this system, mutant strains will be obtained by allelic exchange with deletion of the complete operon and individual genes. The mutants will be characterized by in vitro heme utilization assays and in vivo mouse virulence assays. Furthermore, in vitro biochemical assays will be performed with the purified proteins ChuP and ChuS to determine their roles in regulation of the chuPRSTUV operon and heme degradation, respectively. Together, the data obtained from this work will help to elucidate the strategies that C. violaceum uses to uptake and degrade heme from the environment and the host, and the importance of heme in the pathogenesis of this bacterium.

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)

DE LIMA, VINICIUS M.; BATISTA, BIANCA B.; DA SILVA NETO, JOSE F.. The Regulatory Protein ChuP Connects Heme and Siderophore-Mediated Iron Acquisition Systems Required for Chromobacterium violaceum Virulence. FRONTIERS IN CELLULAR AND INFECTION MICROBIOLOGY, v. 12, p. 15-pg., 2022-05-11. (18/19058-2, 20/00259-8, 18/17716-2, 18/01388-6)

Academic Publications

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

LIMA, Vinicius Marques de. Mechanisms of heme uptake in Chromobacterium violaceum. 2020. Master's Dissertation - Universidade de São Paulo (USP). Faculdade de Medicina de Ribeirão Preto (PCARP/BC) Ribeirão Preto.