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Article

  • The EMBO Journal (2007) 26, 3322 - 3331
  • doi:10.1038/sj.emboj.7601770

Published online: 21 June 2007

Evolution of a bacteriophytochrome from light to redox sensor

Laurie Vuillet1, Mila Kojadinovic2, Sébastien Zappa2, Marianne Jaubert1, Jean-Marc Adriano2, Joël Fardoux1, Laure Hannibal1, David Pignol2, André Verméglio2 and Eric Giraud1,a

  1. Laboratoire des Symbioses Tropicales et Méditerranéennes, IRD, CIRAD, AGRO-M, INRA, UM2, Campus de Baillarguet, Montpellier Cedex, France
  2. CEA Cadarache, DSV/IBEB/SBVME/LBC, UMR 6191 CNRS/CEA/Université Aix-Marseille, Saint-Paul-lez-Durance, France

Correspondence to:

André Verméglio, SBVME-Laboratoire de Bioénergétique Cellulaire, CEA Cadarache bâtment 156, DSV/IBEB/SBVME/LBC, UMR 6191 CNRS/CEA/Université Aix-Marseille, Saint Paul lez Durance 13108, France. Tel.: +33 44225 4630; Fax: +33 4422 54701; E-mail: avermeglio@cea.fr

aThese authors contributed equally to this work

Received 27 April 2007; Accepted 29 May 2007

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.

  • Keywords:

    • bacteriophytochrome,
    • light harvesting complexes,
    • redox sensing,
    • Rhodopseudomonas palustris