Year: 2019
Type: article
Abstract: SUMMARY Type VI secretion systems (T6SSs) are widespread, tightly regulated, protein delivery apparatuses used by Gram-negative bacteria to outcompete their neighbors. The pathogen, Vibrio parahaemolyticus , encodes two T6SSs. These T6SSs are differentially regulated by external conditions. T6SS1, an antibacterial system predominantly found in pathogenic isolates, requires warm marine-like conditions and surface sensing for activation. The regulatory network that governs this activation is not well understood. In this work, we devised a screening methodology that allows us to easily monitor the outcome of bacterial competitions and thus, to identify mutants that are defective in T6SS1-mediated bacterial killing. The methodology, termed Bacterial Competition Fluorescence (BaCoF), relies on detection of a fluorescent signal as an indicator of the survival and growth of a T6SS-sensitive, GFP-expressing prey that has been co-cultured with mutants derived from a T6SS + attacker of interest. Using BaCoF, we screened a random transposon insertion mutant library and identified genes required for V. parahaemolyticus T6SS1 activation, among them TfoY and Tmk. We used epistasis experiments to determine the relationships between the newly identified components and other regulators that were previously described. Thus, we present here a detailed biological understanding of the T6SS1 regulatory network.
Source: Environmental Microbiology
Authors: Rotem Ben-Yaakov, Dor Salomon
Institution: Tel Aviv University
Language: English
Subfield: Endocrinology
Domain: Life Sciences
Open Access status: hybrid
Estimated APC paid: $4,200
OpenAlex ID: W2921015205