Characterization of two members of the cryptochrome/photolyase family from Ostreococcus tauri provides insights into the origin and evolution of cryptochromes.
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.
Heijde
Marc
M
Ecole Normale Supérieure, Institut de Biologie de l'ENS, IBENS, CNRS UMR 8197, Paris, F-75005 France.
Zabulon
Gérald
G
Corellou
Florence
F
Ishikawa
Tomoko
T
Brazard
Johanna
J
Usman
Anwar
A
Sanchez
Frédéric
F
Plaza
Pascal
P
Martin
Monique
M
Falciatore
Angela
A
Todo
Takeshi
T
Bouget
François-Yves
FY
Bowler
Chris
C
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
D056931:Cryptochromes; D018744:DNA, Plant; D012097:Repressor Proteins; D004255:Deoxyribodipyrimidine Photo-Lyase