title: Evolution of a bacteriophytochrome from light to redox sensor.
abstract: Bacteriophytochromes are red/far-red photoreceptors that bacteria use to mediate sensory responses to their light environment. Here, we show that the photosynthetic bacterium Rhodopseudomonas palustris has two distinct types of bacteriophytochrome-related protein (RpBphP4) depending upon the strain considered. The first type binds the chromophore biliverdin and acts as a light-sensitive kinase, thus behaving as a bona fide bacteriophytochrome. However, in most strains, RpBphP4 does not to bind this chromophore. This loss of light sensing is replaced by a redox-sensing ability coupled to kinase activity. Phylogenetic analysis is consistent with an evolutionary scenario, where a bacteriophytochrome ancestor has adapted from light to redox sensing. Both types of RpBphP4 regulate the synthesis of light harvesting (LH2) complexes according to the light or redox conditions, respectively. They modulate the affinity of a transcription factor binding to the promoter regions of LH2 complex genes by controlling its phosphorylation status. This is the first complete description of a bacteriophytochrome signal transduction pathway involving a two-component system.
authors.affiliation: Laboratoire des Symbioses Tropicales et Méditerranéennes, IRD, CIRAD, AGRO-M, INRA, UM2, Campus de Baillarguet, Montpellier Cedex, France.
authors.forename: Laurie
authors.initials: L
authors.lastname: Vuillet
authors.forename: Mila
authors.initials: M
authors.lastname: Kojadinovic
authors.forename: Sébastien
authors.initials: S
authors.lastname: Zappa
authors.forename: Marianne
authors.initials: M
authors.lastname: Jaubert
authors.forename: Jean-Marc
authors.initials: JM
authors.lastname: Adriano
authors.forename: Joël
authors.initials: J
authors.lastname: Fardoux
authors.forename: Laure
authors.initials: L
authors.lastname: Hannibal
authors.forename: David
authors.initials: D
authors.lastname: Pignol
authors.forename: André
authors.initials: A
authors.lastname: Verméglio
authors.forename: Eric
authors.initials: E
authors.lastname: Giraud
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D019143:Evolution, Molecular; D008027:Light; D045342:Light-Harvesting Protein Complexes / Q000096:biosynthesis / Q000187:drug effects / Q000528:radiation effects; D008954:Models, Biological; D008969:Molecular Sequence Data; D010084:Oxidation-Reduction / Q000528:radiation effects; D010100:Oxygen / Q000494:pharmacology; D010788:Photosynthesis / Q000187:drug effects / Q000528:radiation effects; D010802:Phylogeny; D010834:Phytochrome / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D011401:Promoter Regions, Genetic / Q000235:genetics; D011994:Recombinant Proteins / Q000235:genetics / Q000302:isolation & purification; D012241:Rhodopseudomonas / Q000187:drug effects / Q000235:genetics / Q000378:metabolism* / Q000528:radiation effects; D015398:Signal Transduction / Q000187:drug effects; D014157:Transcription Factors / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D045342:Light-Harvesting Protein Complexes; D011994:Recombinant Proteins; D014157:Transcription Factors; D010834:Phytochrome; D010100:Oxygen