Diatom PtCPF1 is a new cryptochrome/photolyase family member with DNA repair and transcription regulation activity.
Members of the cryptochrome/photolyase family (CPF) are widely distributed throughout all kingdoms, and encode photosensitive proteins that typically show either photoreceptor or DNA repair activity. Animal and plant cryptochromes have lost DNA repair activity and now perform specialized photoperceptory functions, for example, plant cryptochromes regulate growth and circadian rhythms, whereas mammalian and insect cryptochromes act as transcriptional repressors that control the circadian clock. However, the functional differentiation between photolyases and cryptochromes is now being questioned. Here, we show that the PtCPF1 protein from the marine diatom Phaeodactylum tricornutum shows 6-4 photoproduct repair activity and can act as a transcriptional repressor of the circadian clock in a heterologous mammalian cell system. Conversely, it seems to have a wide role in blue-light-regulated gene expression in diatoms. The protein might therefore represent a missing link in the evolution of CPFs, and act as a novel ultraviolet/blue light sensor in marine environments.
Department of Ecology and Evolution of Plankton, Stazione Zoologica Anton Dohrn, Villa Comunale, Naples 80121, Italy.
Sacha
S
Coesel
Manuela
M
Mangogna
Tomoko
T
Ishikawa
Marc
M
Heijde
Alessandra
A
Rogato
Giovanni
G
Finazzi
Takeshi
T
Todo
Chris
C
Bowler
Angela
A
Falciatore
D020418:Algal Proteins / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D019556:COS Cells; D002522:Chlorocebus aethiops; D056931:Cryptochromes; D004260:DNA Repair; D017377:Diatoms / Q000235:genetics*; D005420:Flavoproteins / Q000235:genetics / Q000378:metabolism*; D005786:Gene Expression Regulation; D010802:Phylogeny; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism; D014158:Transcription, Genetic
D020418:Algal Proteins; D056931:Cryptochromes; D005420:Flavoproteins; D012097:Repressor Proteins