title: Signal transduction and adaptive regulation through bacterial two-component systems: the Escherichia coli AtoSC paradigm.
abstract: Adaptive signal transduction within microbial cells involves a multi-faceted regulated phosphotransfer mechanism that comprises structural rearrangements of sensor histidine kinases upon ligand-binding and phosphorylation-induced conformational changes in response regulators of versatile two-component systems (TCS), arisen early in bacterial evolution. In Escherichia coli, cross-talk between the AtoS histidine kinase and the AtoC response regulator, forming the AtoSC TCS, through His --> Asp phosphotransfer, activates AtoC directly to induce atoDAEB operon expression, thus modulating diverse fundamental cellular processes such as short-chain fatty acid catabolism, poly-(R)-3-hydroxybutyrate biosynthesis and chemotaxis. Among the inducers hitherto identified, acetoacetate is the classical activator. The AtoSC TCS functional modulation by polyamines, histamine and Ca(2+), as well as the role of AtoC as transcriptional regulator, add new promising perspectives in the physiological significance and potential pharmacological exploitation of this TCS in cell proliferation, bacteria-host interactions, chemotaxis, and adaptation.
authors.affiliation: Department of Chemistry, Aristotle University of Thessaloniki, Greece. kyr@eie.gr
authors.forename: Dimitrios A
authors.initials: DA
authors.lastname: Kyriakidis
authors.forename: Ekaterini
authors.initials: E
authors.lastname: Tiligada
mesh_terms: D000222:Adaptation, Physiological; D004268:DNA-Binding Proteins / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000378:metabolism*; D000071677:Histidine Kinase; D009876:Operon; D010802:Phylogeny; D011494:Protein Kinases / Q000378:metabolism*; D015398:Signal Transduction / Q000502:physiology*; D014157:Transcription Factors / Q000378:metabolism*; D015533:Transcriptional Activation
chemical_list: C505587:AtoC protein, E coli; D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; D014157:Transcription Factors; D011494:Protein Kinases; D000071677:Histidine Kinase; C505586:AtoS protein, E coli