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 Apr 08
KeywordsBacteriophages, DNA-Binding Proteins, Escherichia coli, Gene Expression Regulation, Bacterial, Genes, Viral, Lysogeny, Prophages, Quorum Sensing, Repressor Proteins, Viral Proteins, Viral Regulatory and Accessory Proteins

<p>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 (cI), leading to host-cell lysis. Here, we show that Qtip interacts with the N terminus of cI, inhibiting both cI DNA binding and cI autoproteolysis. Qtip also sequesters cI, localizing it to the poles. Qtip can localize to the poles independently of cI. Alanine-scanning mutagenesis of Qtip shows that its localization and interference with cI 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.</p>

Alternate JournalCell Host Microbe
PubMed ID32101705
PubMed Central IDPMC7148176
Grant List / HHMI / Howard Hughes Medical Institute / United States
R37 GM065859 / GM / NIGMS NIH HHS / United States
T32 GM007388 / GM / NIGMS NIH HHS / United States