title: Regulation of Arabidopsis cryptochrome 2 by blue-light-dependent phosphorylation.
abstract: Cryptochromes are blue/ultraviolet-A light receptors that mediate various light responses in plants and animals. But the initial photochemical reaction of cryptochrome is still unclear. For example, although most photoreceptors are known to undergo light-dependent protein modification such as phosphorylation, no blue-light dependent phosphorylation has been reported for a cryptochrome. Arabidopsis cryptochrome 2 (cry2) mediates light regulation of seedling development and photoperiodic flowering. The physiological activity and cellular level of cry2 protein are light-dependent, and protein protein interactions are important for cry2 function. Here we report that cry2 undergoes a blue-light-dependent phosphorylation, and that cry2 phosphorylation is associated with its function and regulation. Our results suggest that, in the absence of light, cry2 remains unphosphorylated, inactive and stable; absorption of blue light induces the phosphorylation of cry2, triggering photomorphogenic responses and eventually degradation of the photoreceptor.
authors.affiliation: Department of Molecular, Cell & Developmental Biology, University of California, Los Angeles, California 90095, USA.
authors.forename: Dror
authors.initials: D
authors.lastname: Shalitin
authors.forename: Hongyun
authors.initials: H
authors.lastname: Yang
authors.forename: Todd C
authors.initials: TC
authors.lastname: Mockler
authors.forename: Maskit
authors.initials: M
authors.lastname: Maymon
authors.forename: Hongwei
authors.initials: H
authors.lastname: Guo
authors.forename: Garry C
authors.initials: GC
authors.lastname: Whitelam
authors.forename: Chentao
authors.initials: C
authors.lastname: Lin
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism* / Q000528:radiation effects*; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D015153:Blotting, Western; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism; D003116:Color; D056931:Cryptochromes; D003624:Darkness; D029721:Drosophila Proteins; D005136:Eye Proteins; D005420:Flavoproteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant / Q000528:radiation effects; D017343:Genes, Plant / Q000235:genetics; D007700:Kinetics; D008027:Light; D009154:Mutation; D010766:Phosphorylation / Q000528:radiation effects; D017440:Photoperiod; D017956:Photoreceptor Cells, Invertebrate; D010834:Phytochrome / Q000235:genetics / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D030821:Plants, Genetically Modified; D011233:Precipitin Tests; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D043562:Receptors, G-Protein-Coupled; D044767:Ubiquitin-Protein Ligases
chemical_list: D029681:Arabidopsis Proteins; C538962:CRY1 protein, Arabidopsis; D002352:Carrier Proteins; D056931:Cryptochromes; D029721:Drosophila Proteins; D005136:Eye Proteins; D005420:Flavoproteins; D010940:Plant Proteins; D043562:Receptors, G-Protein-Coupled; C119828:cry protein, Drosophila; D010834:Phytochrome; C471983:AT2G32950 protein, Arabidopsis; D044767:Ubiquitin-Protein Ligases