title: Characterization of two members of the cryptochrome/photolyase family from Ostreococcus tauri provides insights into the origin and evolution of cryptochromes.
abstract: Cryptochromes (Crys) are blue light receptors believed to have evolved from the DNA photolyase protein family, implying that light control and light protection share a common ancient origin. In this paper, we report the identification of five genes of the Cry/photolyase family (CPF) in two green algae of the Ostreococcus genus. Phylogenetic analyses were used to confidently assign three of these sequences to cyclobutane pyrimidine dimer (CPD) photolyases, one of them to a DASH-type Cry, and a third CPF gene has high homology with the recently described diatom CPF1 that displays a bifunctional activity. Both purified OtCPF1 and OtCPF2 proteins show non-covalent binding to flavin adenine dinucleotide (FAD), and additionally to 5,10-methenyl-tetrahydrofolate (MTHF) for OtCPF2. Expression analyses revealed that all five CPF members of Ostreococcus tauri are regulated by light. Furthermore, we show that OtCPF1 and OtCPF2 display photolyase activity and that OtCPF1 is able to interact with the CLOCK:BMAL heterodimer, transcription factors regulating circadian clock function in other organisms. Finally, we provide evidence for the involvement of OtCPF1 in the maintenance of the Ostreococcus circadian clock. This work improves our understanding of the evolutionary transition between photolyases and Crys.
authors.affiliation: Ecole Normale Supérieure, Institut de Biologie de l'ENS, IBENS, CNRS UMR 8197, Paris, F-75005 France.
authors.forename: Marc
authors.initials: M
authors.lastname: Heijde
authors.forename: Gérald
authors.initials: G
authors.lastname: Zabulon
authors.forename: Florence
authors.initials: F
authors.lastname: Corellou
authors.forename: Tomoko
authors.initials: T
authors.lastname: Ishikawa
authors.forename: Johanna
authors.initials: J
authors.lastname: Brazard
authors.forename: Anwar
authors.initials: A
authors.lastname: Usman
authors.forename: Frédéric
authors.initials: F
authors.lastname: Sanchez
authors.forename: Pascal
authors.initials: P
authors.lastname: Plaza
authors.forename: Monique
authors.initials: M
authors.lastname: Martin
authors.forename: Angela
authors.initials: A
authors.lastname: Falciatore
authors.forename: Takeshi
authors.initials: T
authors.lastname: Todo
authors.forename: François-Yves
authors.initials: FY
authors.lastname: Bouget
authors.forename: Chris
authors.initials: C
authors.lastname: Bowler
mesh_terms: D005075:Biological Evolution; D000460:Chlorophyta / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D057906:Circadian Clocks / Q000235:genetics; D056931:Cryptochromes / Q000737:chemistry / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D004260:DNA Repair; D018744:DNA, Plant / Q000378:metabolism; D004255:Deoxyribodipyrimidine Photo-Lyase / Q000737:chemistry / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D018506:Gene Expression Regulation, Plant / Q000502:physiology*; D008027:Light; D017440:Photoperiod; D010802:Phylogeny; D011485:Protein Binding; D012097:Repressor Proteins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D013050:Spectrometry, Fluorescence
chemical_list: D056931:Cryptochromes; D018744:DNA, Plant; D012097:Repressor Proteins; D004255:Deoxyribodipyrimidine Photo-Lyase