title: OpaR controls a network of downstream transcription factors in Vibrio parahaemolyticus BB22OP.
abstract: Vibrio parahaemolyticus is an emerging world-wide human pathogen that is associated with food-borne gastroenteritis when raw or undercooked seafood is consumed. Expression of virulence factors in this organism is modulated by the phenomenon known as quorum sensing, which permits differential gene regulation at low versus high cell density. The master regulator of quorum sensing in V. parahaemolyticus is OpaR. OpaR not only controls virulence factor gene expression, but also the colony and cellular morphology associated with growth on a surface and biofilm formation. Whole transcriptome Next Generation sequencing (RNA-Seq) was utilized to determine the OpaR regulon by comparing strains BB22OP (opaR+, LM5312) and BB22TR (∆opaR1, LM5674). This work, using the published V. parahaemolyticus BB22OP genome sequence, confirms and expands upon a previous microarray analysis for these two strains that used an Affymetrix GeneChip designed from the closely related V. parahaemolyticus RIMD2210633 genome sequence. Overall there was excellent correlation between the microarray and RNA-Seq data. Eleven transcription factors under OpaR control were identified by both methods and further confirmed by quantitative reverse transcription PCR (qRT-PCR) analysis. Nine of these transcription factors were demonstrated to be direct OpaR targets via in vitro electrophoretic mobility shift assays with purified hexahistidine-tagged OpaR. Identification of the direct and indirect targets of OpaR, including small RNAs, will enable the construction of a network map of regulatory interactions important for the switch between the nonpathogenic and pathogenic states.
authors.affiliation: Department of Biological Sciences, Virginia Tech, Blacksburg, VA, United States of America.
authors.forename: Alison
authors.initials: A
authors.lastname: Kernell Burke
authors.affiliation: Department of Biological Sciences, Virginia Tech, Blacksburg, VA, United States of America.
authors.forename: Leah T C
authors.initials: LT
authors.lastname: Guthrie
authors.affiliation: Department of Biological Sciences, Virginia Tech, Blacksburg, VA, United States of America.
authors.forename: Thero
authors.initials: T
authors.lastname: Modise
authors.affiliation: Georgia Advanced Computing Resource Center, University of Georgia, Athens, GA, United States of America.
authors.forename: Guy
authors.initials: G
authors.lastname: Cormier
authors.affiliation: Department of Biological Sciences, Virginia Tech, Blacksburg, VA, United States of America.
authors.forename: Roderick V
authors.initials: RV
authors.lastname: Jensen
authors.affiliation: Department of Microbiology, University of Iowa, Iowa City, IA, United States of America.
authors.forename: Linda L
authors.initials: LL
authors.lastname: McCarter
authors.affiliation: Department of Biological Sciences, Virginia Tech, Blacksburg, VA, United States of America.
authors.forename: Ann M
authors.initials: AM
authors.lastname: Stevens
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics*; D015153:Blotting, Western; D024202:Electrophoretic Mobility Shift Assay; D015964:Gene Expression Regulation, Bacterial; D059014:High-Throughput Nucleotide Sequencing / Q000379:methods; D006801:Humans; D011401:Promoter Regions, Genetic / Q000235:genetics; D053038:Quorum Sensing; D012333:RNA, Messenger / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D012045:Regulatory Sequences, Nucleic Acid / Q000235:genetics; D018085:Regulon / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D014736:Vibrio parahaemolyticus / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism*; D037521:Virulence Factors / Q000235:genetics
chemical_list: D001426:Bacterial Proteins; C500454:OpaR protein, Vibrio parahaemolyticus; D012333:RNA, Messenger; D014157:Transcription Factors; D037521:Virulence Factors