Functional characterization of a new T6SS antibacterial effector of Salmonella enterica

• Grant number: 22/01364-5
• Support Opportunities: Scholarships in Brazil - Master
• Effective date (Start): September 01, 2022
• Effective date (End): February 29, 2024
• Field of knowledge: Biological Sciences - Microbiology - Biology and Physiology of Microorganisms
• Principal Investigator: Ethel Bayer Santos
• Grantee: Julia Takuno Hespanhol
• Host Institution: Instituto de Ciências Biomédicas (ICB). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant: 17/02178-2 - Function of type VI secretion systems of pathogenic bacteria in the interaction with eukaryotic cells, AP.JP

Abstract

Bacteria developed different mechanisms of antagonism, either independent or dependent of contact between cells, to compete for resources in microbial communities. The Type VI Secretion System (T6SS) is a contact dependent antagonic mechanism, which consists of a contractile nanomachine capable of injecting toxic effectors into target cells. The T6SS effectors present a broad spectrum of biochemical activities and cellular targets that aim to disable or kill competitor cells. Salmonella spp. encode different T6SSs in Salmonella Pathogenicity Islands (SPIs). The SPI-6 T6SS of S. enterica Typhimurium and the SPI-22 T6SS of S. bongori have been characterized and show antibacterial activity. Despite the importance of T6SSs for Salmonella spp. pathogenicity, so far only three effectors have been described. Our group is interested in identifying and characterizing new antibacterial effectors. Using in silico approaches to analyse thousands of Salmonella spp. genomes, we identified a list of putative effectors with unknown domains. The objective of this work is to describe the molecular function of one of these new effectors that presented toxicity in Escherichia coli. At the end, we aim to describe the function of a new protein domain, characterizing the antibacterial mechanism. Furthermore, we will perform a phylogenetic analysis to stablish the evolutionary origin of this new biological weapon. This work could contribute to the development of strategies to fight bacterial infections and antimicrobial resistance.

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)

JULIA TAKUNO HESPANHOL; LIOR KARMAN; DANIEL ENRIQUE SANCHEZ-LIMACHE; ETHEL BAYER-SANTOS. Intercepting biological messages: Antibacterial molecules targeting nucleic acids during interbacterial conflicts. GENETICS AND MOLECULAR BIOLOGY, v. 46, n. 1, 2023-03-06. (17/02178-2, 22/01444-9, 22/01364-5, 19/22715-8, 18/04553-8)