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

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.

Alternate JournalCell Host Microbe
PubMed ID32101705