title: Characterization of the AtsR hybrid sensor kinase phosphorelay pathway and identification of its response regulator in Burkholderia cenocepacia.
abstract: AtsR is a membrane-bound hybrid sensor kinase of Burkholderia cenocepacia that negatively regulates quorum sensing and virulence factors such as biofilm production, type 6-secretion, and protease secretion. Here we elucidate the mechanism of AtsR phosphorelay by site-directed mutagenesis of predicted histidine and aspartic acid phosphoacceptor residues. We demonstrate by in vitro phosphorylation that histidine 245 and aspartic acid 536 are conserved sites of phosphorylation in AtsR, and we also identify the cytosolic response regulator AtsT (BCAM0381) as a key component of the AtsR phosphorelay pathway. Monitoring the function of AtsR and its derivatives in vivo by measuring extracellular protease activity and swarming motility confirmed the in vitro phosphorylation results. Together we find that the AtsR receiver domain plays a fine-tuning role in determining the levels of phosphotransfer from its sensor kinase domain to the AtsT response regulator.
authors.affiliation: From the Centre for Human Immunology, Department of Microbiology and Immunology, Schulich School of Medicine, University of Western Ontario, London, Ontario N6A 5C1, Canada and.
authors.forename: Maryam
authors.initials: M
authors.lastname: Khodai-Kalaki
authors.affiliation: From the Centre for Human Immunology, Department of Microbiology and Immunology, Schulich School of Medicine, University of Western Ontario, London, Ontario N6A 5C1, Canada and.
authors.forename: Daniel F
authors.initials: DF
authors.lastname: Aubert
authors.affiliation: From the Centre for Human Immunology, Department of Microbiology and Immunology, Schulich School of Medicine, University of Western Ontario, London, Ontario N6A 5C1, Canada and; the Centre for Infection and Immunity, Queen's University Belfast, BT9 5GZ Belfast, United Kingdom. Electronic address: m.valvano@qub.ac.uk.
authors.forename: Miguel A
authors.initials: MA
authors.lastname: Valvano
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D058947:Bacterial Secretion Systems / Q000502:physiology; D019121:Burkholderia Infections / Q000201:enzymology / Q000235:genetics; D057508:Burkholderia cenocepacia / Q000201:enzymology* / Q000235:genetics / Q000472:pathogenicity; D002460:Cell Line; D051379:Mice; D010766:Phosphorylation / Q000502:physiology; D011494:Protein Kinases / Q000235:genetics / Q000378:metabolism*; D053038:Quorum Sensing / Q000502:physiology*; D015398:Signal Transduction / Q000502:physiology*
chemical_list: D001426:Bacterial Proteins; D058947:Bacterial Secretion Systems; D011494:Protein Kinases
keywords: Bacterial Protein Kinases; Cystic Fibrosis; Histidine Kinases; Macrophages; Phosphorylation; Protease; Transcription Regulation; Virulence Factors