title: LOV2-linker-kinase phosphorylates LOV1-containing N-terminal polypeptide substrate via photoreaction of LOV2 in Arabidopsis phototropin1.
abstract: Phototropin is a blue light receptor in plants and is thought to be a light-regulated protein kinase. Previously, we defined the role of the photoreceptive domains, LOV1 and 2, in the light activation of the kinase in Arabidopsis phototropin2 (phot2). In this study, photoregulation of the kinase in phototropin1 (phot1) was studied using LOV2-linker-kinase polypeptide. We designed a new substrate consisting of the N-terminal part of the phot1 with autophosphorylation sites. The LOV2-linker-kinase had the same spectroscopic properties as those of the LOV2 core and phosphorylated the substrate in a light-dependent manner. Amino acid substitution experiments proved that the phosphorylation comes from the activation of the kinase via photoreaction of LOV2.
authors: Department of Biological Sciences, Graduate School of Science, Osaka Prefecture University, Gakuen-cho 1-1, Nakaku, Sakai, Osaka 599-8531, Japan.
authors: Koji
authors: K
authors: Okajima
authors: Daisuke
authors: D
authors: Matsuoka
authors: Satoru
authors: S
authors: Tokutomi
mesh_terms: D017360:Arabidopsis / Q000201:enzymology / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000737:chemistry* / Q000378:metabolism*; D001665:Binding Sites; D004789:Enzyme Activation / Q000528:radiation effects; D008027:Light; D010446:Peptide Fragments / Q000737:chemistry / Q000378:metabolism*; D010750:Phosphoproteins / Q000737:chemistry* / Q000378:metabolism*; D010766:Phosphorylation / Q000528:radiation effects; D011494:Protein Kinases / Q000737:chemistry* / Q000378:metabolism*; D055503:Protein Multimerization; D017346:Protein Serine-Threonine Kinases; D020836:Protein Structure, Quaternary; D017434:Protein Structure, Tertiary; D013056:Spectrophotometry, Ultraviolet
chemical_list: D029681:Arabidopsis Proteins; D010446:Peptide Fragments; D010750:Phosphoproteins; D011494:Protein Kinases; C103646:NPH1 protein, Arabidopsis; D017346:Protein Serine-Threonine Kinases