title: Blue-light-dependent interaction of cryptochrome 1 with SPA1 defines a dynamic signaling mechanism.
abstract: Cryptochromes (CRYs) are blue-light photoreceptors that mediate various light responses in plants and animals. The signaling mechanism by which CRYs regulate light responses involves their physical interactions with COP1. Here, we report that CRY1 interacts physically with SPA1 in a blue-light-dependent manner. SPA acts genetically downstream from CRYs to regulate light-controlled development. Blue-light activation of CRY1 attenuates the association of COP1 with SPA1 in both yeast and plant cells. These results indicate that the blue-light-triggered CRY1-SPA1 interaction may negatively regulate COP1, at least in part, by promoting the dissociation of COP1 from SPA1. This interaction and consequent dissociation define a dynamic photosensory signaling mechanism.
authors.affiliation: Plant Science Institute, School of Agriculture and Biology, Shanghai Jiaotong University, Shanghai, China.
authors.forename: Hong-Li
authors.initials: HL
authors.lastname: Lian
authors.forename: Sheng-Bo
authors.initials: SB
authors.lastname: He
authors.forename: Yan-Chun
authors.initials: YC
authors.lastname: Zhang
authors.forename: Dan-Meng
authors.initials: DM
authors.lastname: Zhu
authors.forename: Jing-Yi
authors.initials: JY
authors.lastname: Zhang
authors.forename: Kun-Peng
authors.initials: KP
authors.lastname: Jia
authors.forename: Shu-Xia
authors.initials: SX
authors.lastname: Sun
authors.forename: Ling
authors.initials: L
authors.lastname: Li
authors.forename: Hong-Quan
authors.initials: HQ
authors.lastname: Yang
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development / Q000378:metabolism / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000378:metabolism*; D018797:Cell Cycle Proteins / Q000378:metabolism*; D056931:Cryptochromes / Q000378:metabolism*; D008027:Light; D017434:Protein Structure, Tertiary; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction; D020798:Two-Hybrid System Techniques
chemical_list: D029681:Arabidopsis Proteins; C538962:CRY1 protein, Arabidopsis; C103618:CRY2 protein, Arabidopsis; D018797:Cell Cycle Proteins; D056931:Cryptochromes; C118571:SPA1 protein, Arabidopsis