Control of the light harvesting function of chloroplast membranes: the LHCII-aggregation model for non-photochemical quenching.
Dissipation of excess excitation energy within the photosystem II light-harvesting antenna (LHCII) by non-photochemical quenching (NPQ) is an important photoprotective process in plants. An update to a hypothesis for the mechanism of NPQ [FEBS Letters 292, 1991] is presented. The impact of recent advances in understanding the structure, organisation and photophysics of LHCII is assessed. We show possible locations of the predicted regulatory and quenching pigment-binding sites in the structural model of the major LHCII. We suggest that NPQ is a highly regulated concerted response of the organised thylakoid macrostructure, which can include different mechanisms and sites at different times.
Horton
Peter
P
Department of Molecular Biology and Biotechnology, University of Sheffield, Western Bank, Sheffield S10 2TN, UK. p.horton@sheffield.ac.uk
Wentworth
Mark
M
Ruban
Alexander
A
D000495:Allosteric Site; D045342:Light-Harvesting Protein Complexes / Q000737:chemistry / Q000378:metabolism*; D008954:Models, Biological; D045322:Photosynthetic Reaction Center Complex Proteins / Q000378:metabolism; D045332:Photosystem II Protein Complex / Q000737:chemistry / Q000378:metabolism*; D010940:Plant Proteins / Q000378:metabolism; D010944:Plants / Q000201:enzymology; D011487:Protein Conformation; D020524:Thylakoids / Q000201:enzymology*; D024341:Xanthophylls / Q000378:metabolism*
D045342:Light-Harvesting Protein Complexes; D045322:Photosynthetic Reaction Center Complex Proteins; D045332:Photosystem II Protein Complex; D010940:Plant Proteins; D024341:Xanthophylls