Separating Functions of the Phage-Encoded Quorum-Sensing-Activated Antirepressor Qtip.

TitleSeparating Functions of the Phage-Encoded Quorum-Sensing-Activated Antirepressor Qtip.
Publication TypeJournal Article
Year of Publication2020
AuthorsSilpe, JE, Bridges, AA, Huang, X, Coronado, DR, Duddy, OP, Bassler, BL
JournalCell Host Microbe
Date Published2020 Feb 19
ISSN1934-6069
Abstract

Quorum sensing is a process of chemical communication that bacteria use to track cell density and coordinate gene expression across a population. Bacteria-infecting viruses, called phages, can encode quorum-sensing components that enable them to integrate host cell density information into the lysis-lysogeny decision. Vibriophage VP882 is one such phage, and activation of its quorum-sensing pathway leads to the production of an antirepressor called Qtip. Qtip interferes with the prophage repressor (cIVP882), leading to host-cell lysis. Here, we show that Qtip interacts with the N terminus of cIVP882, inhibiting both cIVP882 DNA binding and cIVP882 autoproteolysis. Qtip also sequesters cIVP882, localizing it to the poles. Qtip can localize to the poles independently of cIVP882. Alanine-scanning mutagenesis of Qtip shows that its localization and interference with cIVP882 activities are separable. Comparison of Qtip to a canonical phage antirepressor reveals that despite both proteins interacting with their partner repressors, only Qtip drives polar localization.

DOI10.1016/j.chom.2020.01.024
Alternate JournalCell Host Microbe
PubMed ID32101705