title: The blue light-dependent phosphorylation of the CCE domain determines the photosensitivity of Arabidopsis CRY2.
abstract: Arabidopsis cryptochrome 2 (CRY2) is a blue light receptor that mediates light inhibition of hypocotyl elongation and long-day promotion of floral initiation. CRY2 is known to undergo blue light-dependent phosphorylation, which is believed to serve regulatory roles in the function of CRY2. We report here on a biochemical and genetics study of CRY2 phosphorylation. Using mass spectrometry analysis, we identified three serine residues in the CCE domain of CRY2 (S598, S599, and S605) that undergo blue light-dependent phosphorylation in Arabidopsis seedlings. A study of serine-substitution mutations in the CCE domain of CRY2 demonstrates that CRY2 contains two types of phosphorylation in the CCE domain, one in the serine cluster that causes electrophoretic mobility upshift and the other outside the serine cluster that does not seem to cause mobility upshift. We showed that mutations in the serine residues within and outside the serine cluster diminished blue light-dependent CRY2 phosphorylation, degradation, and physiological activities. These results support the hypothesis that blue light-dependent phosphorylation of the CCE domain determines the photosensitivity of Arabidopsis CRY2.
authors: Basic Forestry and Proteomics Research Center, Fujian Agriculture and Forestry University, Fuzhou, China; Hunan Province Key Laboratory of Plant Functional Genomics and Developmental Regulation, College of Biology, Hunan University, Changsha 410082, China; Department of Molecular, Cell & Developmental Biology, University of California, Los Angeles, CA 90095, USA.
authors: Qin
authors: Q
authors: Wang
authors: Department of Biological Chemistry, University of California, Los Angeles, CA 90095, USA.
authors: William D
authors: WD
authors: Barshop
authors: Laboratory of Soil and Plant Molecular Genetics, College of Plant Science, Jilin University, Changchun 130062, China.
authors: Mingdi
authors: M
authors: Bian
authors: Department of Biological Chemistry, University of California, Los Angeles, CA 90095, USA.
authors: Ajay A
authors: AA
authors: Vashisht
authors: Hunan Province Key Laboratory of Plant Functional Genomics and Developmental Regulation, College of Biology, Hunan University, Changsha 410082, China.
authors: Reqing
authors: R
authors: He
authors: Department of Molecular, Cell & Developmental Biology, University of California, Los Angeles, CA 90095, USA.
authors: Xuhong
authors: X
authors: Yu
authors: Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
authors: Bin
authors: B
authors: Liu
authors: Department of Molecular, Cell & Developmental Biology, University of California, Los Angeles, CA 90095, USA.
authors: Paula
authors: P
authors: Nguyen
authors: Hunan Province Key Laboratory of Plant Functional Genomics and Developmental Regulation, College of Biology, Hunan University, Changsha 410082, China.
authors: Xuanming
authors: X
authors: Liu
authors: Hunan Province Key Laboratory of Plant Functional Genomics and Developmental Regulation, College of Biology, Hunan University, Changsha 410082, China. Electronic address: zxy_mm@163.com.
authors: Xiaoying
authors: X
authors: Zhao
authors: Department of Biological Chemistry, University of California, Los Angeles, CA 90095, USA.
authors: James A
authors: JA
authors: Wohlschlegel
authors: Department of Molecular, Cell & Developmental Biology, University of California, Los Angeles, CA 90095, USA. Electronic address: clin@mcdb.ucla.edu.
authors: Chentao
authors: C
authors: Lin
mesh_terms: D017360:Arabidopsis / Q000528:radiation effects; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D056931:Cryptochromes / Q000235:genetics / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant / Q000235:genetics / Q000528:radiation effects; D008027:Light; D010766:Phosphorylation / Q000528:radiation effects
chemical_list: D029681:Arabidopsis Proteins; C103618:CRY2 protein, Arabidopsis; D056931:Cryptochromes
keywords: Arabidopsis; light regulation; light signaling; physiology of plant growth