title: Charting the signal trajectory in a light-oxygen-voltage photoreceptor by random mutagenesis and covariance analysis.
abstract: Modular signal receptors empower organisms to process environmental stimuli into adequate physiological responses. At the molecular level, a sensor module receives signals and processes the inherent information into changes of biological activity of an effector module. To better understand the molecular bases underpinning these processes, we analyzed signal reception and processing in the dimeric light-oxygen-voltage (LOV) blue light receptor YF1 that serves as a paradigm for the widespread Per-ARNT-Sim (PAS) signal receptors. Random mutagenesis identifies numerous YF1 variants in which biological activity is retained but where light regulation is abolished or inverted. One group of variants carries mutations within the LOV photosensor that disrupt proper coupling of the flavin-nucleotide chromophore to the protein scaffold. Another larger group bears mutations that cluster at the dyad interface and disrupt signal transmission to two coaxial coiled-coils that connect to the effector. Sequence covariation implies wide conservation of structural and mechanistic motifs, as also borne out by comparison to several PAS domains in which mutations leading to disruption of signal transduction consistently map to confined regions broadly equivalent to those identified in YF1. Not only do these data provide insight into general mechanisms of signal transduction, but also they establish concrete means for customized reprogramming of signal receptors.
authors.affiliation: From the Humboldt-Universität zu Berlin, Institut für Biologie, Biophysikalische Chemie, Invalidenstraße 42, 10115 Berlin, Germany.
authors.forename: Tobias
authors.initials: T
authors.lastname: Gleichmann
authors.forename: Ralph P
authors.initials: RP
authors.lastname: Diensthuber
authors.forename: Andreas
authors.initials: A
authors.lastname: Möglich
mesh_terms: D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D000704:Analysis of Variance; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D001665:Binding Sites / Q000235:genetics; D000071677:Histidine Kinase; D008027:Light; D008958:Models, Molecular; D008969:Molecular Sequence Data; D016296:Mutagenesis; D009154:Mutation; D010100:Oxygen / Q000494:pharmacology; D011494:Protein Kinases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D017434:Protein Structure, Tertiary; D017386:Sequence Homology, Amino Acid; D015398:Signal Transduction / Q000187:drug effects / Q000235:genetics* / Q000528:radiation effects
chemical_list: D001426:Bacterial Proteins; D011494:Protein Kinases; D000071677:Histidine Kinase; D010100:Oxygen
keywords: Covariance Analysis; Histidine Kinases; Light-Oxygen-Voltage; Mutagenesis; Per-ARNT-Sim; Photoreceptors; Receptors; Signal Transduction