title: A mechanism for regulation of chloroplast LHC II kinase by plastoquinol and thioredoxin.
abstract: State transitions are acclimatory responses to changes in light quality in photosynthesis. They involve the redistribution of absorbed excitation energy between photosystems I and II. In plants and green algae, this redistribution is produced by reversible phosphorylation of the chloroplast light harvesting complex II (LHC II). The LHC II kinase is activated by reduced plastoquinone (PQ) in photosystem II-specific low light. In high light, when PQ is also reduced, LHC II kinase becomes inactivated by thioredoxin. Based on newly identified amino acid sequence features of LHC II kinase and other considerations, a mechanism is suggested for its redox regulation.
authors.affiliation: School of Biological and Chemical Sciences, Queen Mary, University of London, London, UK. s.puthiyaveetil@qmul.ac.uk
authors.forename: Sujith
authors.initials: S
authors.lastname: Puthiyaveetil
mesh_terms: D000595:Amino Acid Sequence; D000460:Chlorophyta; D002736:Chloroplasts / Q000201:enzymology; D004735:Energy Transfer; D045342:Light-Harvesting Protein Complexes / Q000737:chemistry / Q000378:metabolism*; D010766:Phosphorylation; D010940:Plant Proteins; D010971:Plastoquinone / Q000031:analogs & derivatives* / Q000494:pharmacology; D011494:Protein Kinases / Q000737:chemistry / Q000378:metabolism*; D013879:Thioredoxins / Q000502:physiology*
chemical_list: D045342:Light-Harvesting Protein Complexes; D010940:Plant Proteins; C003165:plastoquinol; D013879:Thioredoxins; D011494:Protein Kinases; C120337:light-harvesting complex II kinase; D010971:Plastoquinone