LuxT controls specific quorum-sensing-regulated behaviors in Vibrionaceae spp. via repression of qrr1, encoding a small regulatory RNA. Author Michaela Eickhoff, Chenyi Fei, Xiuliang Huang, Bonnie Bassler Publication Year 2021 Type Journal Article Abstract Quorum sensing (QS) is a process of chemical communication bacteria use to transition between individual and collective behaviors. QS depends on the production, release, and synchronous response to signaling molecules called autoinducers (AIs). The marine bacterium Vibrio harveyi monitors AIs using a signal transduction pathway that relies on five small regulatory RNAs (called Qrr1-5) that post-transcriptionally control target genes. Curiously, the small RNAs largely function redundantly making it difficult to understand the necessity for five of them. Here, we identify LuxT as a transcriptional repressor of qrr1. LuxT does not regulate qrr2-5, demonstrating that qrr genes can be independently controlled to drive unique downstream QS gene expression patterns. LuxT reinforces its control over the same genes it regulates indirectly via repression of qrr1, through a second transcriptional control mechanism. Genes dually regulated by LuxT specify public goods including an aerolysin-type pore-forming toxin. Phylogenetic analyses reveal that LuxT is conserved among Vibrionaceae and sequence comparisons predict that LuxT represses qrr1 in additional species. The present findings reveal that the QS regulatory RNAs can carry out both shared and unique functions to endow bacteria with plasticity in their output behaviors. Keywords Quorum Sensing, Escherichia coli, Vibrio cholerae, Bacterial Proteins, RNA, Messenger, Signal Transduction, Genes, Regulator, DNA-Binding Proteins, Regulatory Sequences, Ribonucleic Acid, Phylogeny, Vibrionaceae Journal PLoS Genet Volume 17 Issue 4 Pages e1009336 Date Published 2021 Apr ISSN Number 1553-7404 DOI 10.1371/journal.pgen.1009336 Alternate Journal PLoS Genet PMCID PMC8043402 PMID 33793568 PubMedPubMed CentralGoogle ScholarBibTeXEndNote X3 XML