title: Human blue-light photoreceptor hCRY2 specifically interacts with protein serine/threonine phosphatase 5 and modulates its activity.
abstract: Photolyase/blue-light photoreceptor family of proteins includes cyclobutane pyrimidine dimer photolyase, (6-4) photolyase and blue-light photoreceptors that were recently discovered in Arabidopsis thaliana, Sinapis alba and Chlamydomonas reinhardtii. Recently, we identified two human genes, hCRY1 and hCRY2, belonging to this family. The proteins encoded by these genes have no DNA repair activity and therefore were hypothesized to function in human blue-light response reactions. To identify downstream targets for these putative blue-light photoreceptors we searched for interacting proteins by the yeast two-hybrid method. We found that the tetratricopeptide repeat protein 1, Tpr1, and the protein serine/threonine phosphatase 5 (PP5) that contains the TPR motif specifically interacted with hCRY2. The effect of the hCRY2-PP5 interaction on the protein phosphatase activity was investigated. We found that hCRY2, but not the highly homologous (6-4) photolyase, inhibits the phosphatase activity of PP5. This inhibition may be on the pathway of blue-light signal transduction reaction in humans.
authors.affiliation: Department of Biochemistry and Biophysics, University of North Carolina School of Medicine, Chapel Hill 27599-7260, USA.
authors.forename: S
authors.initials: S
authors.lastname: Zhao
authors.forename: A
authors.initials: A
authors.lastname: Sancar
mesh_terms: D000818:Animals; D056931:Cryptochromes; D029721:Drosophila Proteins; D005136:Eye Proteins; D005420:Flavoproteins / Q000235:genetics / Q000378:metabolism* / Q000528:radiation effects; D006801:Humans; D066298:In Vitro Techniques; D009687:Nuclear Proteins / Q000378:metabolism*; D010749:Phosphoprotein Phosphatases / Q000378:metabolism*; D010786:Photoreceptor Cells / Q000378:metabolism* / Q000528:radiation effects; D017956:Photoreceptor Cells, Invertebrate; D011485:Protein Binding; D043562:Receptors, G-Protein-Coupled; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism / Q000528:radiation effects; D015398:Signal Transduction
chemical_list: D056931:Cryptochromes; D029721:Drosophila Proteins; D005136:Eye Proteins; D005420:Flavoproteins; D009687:Nuclear Proteins; D043562:Receptors, G-Protein-Coupled; D011994:Recombinant Proteins; C119828:cry protein, Drosophila; D010749:Phosphoprotein Phosphatases; C089641:protein phosphatase 5