OPEN ACCESS ARTICLE

This Article Free via Open Access: OA OA Full Text Full Text (PDF) OA All Versions of this Article: 18/11/3106    most recent tpc.106.045641v1 Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via CrossRef Citing Articles via ISI Web of Science (11) Citing Articles via Google Scholar Google Scholar Articles by Kovács, L. Articles by Horton, P. Search for Related Content PubMed PubMed Citation Articles by Kovács, L. Articles by Horton, P. Agricola Articles by Kovács, L. Articles by Horton, P.

Lack of the Light-Harvesting Complex CP24 Affects the Structure and Function of the Grana Membranes of Higher Plant Chloroplasts^[OA]

^a Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield S10 2TN, United Kingdom
^b Umeå Plant Science Centre, Department of Plant Physiology, Umeå University, S-901 87 Umeå, Sweden
^c Department of Biophysical Chemistry, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, 9747 AG Groningen, The Netherlands

³ To whom correspondence should be addressed. E-mail p.horton{at}sheffield.ac.uk; fax 44-114-222-2712.

The photosystem II (PSII) light-harvesting antenna in higher plants contains a number of highly conserved gene products whose function is unknown. Arabidopsis thaliana plants depleted of one of these, the CP24 light-harvesting complex, have been analyzed. CP24-deficient plants showed a decrease in light-limited photosynthetic rate and growth, but the pigment and protein content of the thylakoid membranes were otherwise almost unchanged. However, there was a major change in the macroorganization of PSII within these membranes; electron microscopy and image analysis revealed the complete absence of the C₂S₂M₂ light-harvesting complex II (LHCII)/PSII supercomplex predominant in wild-type plants. Instead, only C₂S₂ supercomplexes, which are deficient in the LHCIIb M-trimers, were found. Spectroscopic analysis confirmed the disruption of the wild-type macroorganization of PSII. It was found that the functions of the PSII antenna were disturbed: connectivity between PSII centers was reduced, and maximum photochemical yield was lowered; rapidly reversible nonphotochemical quenching was inhibited; and the state transitions were altered kinetically. CP24 is therefore an important factor in determining the structure and function of the PSII light-harvesting antenna, providing the linker for association of the M-trimer into the PSII complex, allowing a specific macroorganization that is necessary both for maximum quantum efficiency and for photoprotective dissipation of excess excitation energy.

This article has been cited by other articles:

				T. K. Ahn, T. J. Avenson, M. Ballottari, Y.-C. Cheng, K. K. Niyogi, R. Bassi, and G. R. Fleming Architecture of a Charge-Transfer State Regulating Light Harvesting in a Plant Antenna Protein Science, May 9, 2008; 320(5877): 794 - 797. [Abstract] [Full Text] [PDF]

				S. de Bianchi, L. Dall'Osto, G. Tognon, T. Morosinotto, and R. Bassi Minor Antenna Proteins CP24 and CP26 Affect the Interactions between Photosystem II Subunits and the Electron Transport Rate in Grana Membranes of Arabidopsis PLANT CELL, April 1, 2008; 20(4): 1012 - 1028. [Abstract] [Full Text] [PDF]

				G. Bonente, B. D. Howes, S. Caffarri, G. Smulevich, and R. Bassi Interactions between the Photosystem II Subunit PsbS and Xanthophylls Studied in Vivo and in Vitro J. Biol. Chem., March 28, 2008; 283(13): 8434 - 8445. [Abstract] [Full Text] [PDF]

				A. Z. Kiss, A. V. Ruban, and P. Horton The PsbS Protein Controls the Organization of the Photosystem II Antenna in Higher Plant Thylakoid Membranes J. Biol. Chem., February 15, 2008; 283(7): 3972 - 3978. [Abstract] [Full Text] [PDF]

				T. J. Avenson, T. K. Ahn, D. Zigmantas, K. K. Niyogi, Z. Li, M. Ballottari, R. Bassi, and G. R. Fleming Zeaxanthin Radical Cation Formation in Minor Light-harvesting Complexes of Higher Plant Antenna J. Biol. Chem., February 8, 2008; 283(6): 3550 - 3558. [Abstract] [Full Text] [PDF]

				M. P. Johnson, M. Havaux, C. Triantaphylides, B. Ksas, A. A. Pascal, B. Robert, P. A. Davison, A. V. Ruban, and P. Horton Elevated Zeaxanthin Bound to Oligomeric LHCII Enhances the Resistance of Arabidopsis to Photooxidative Stress by a Lipid-protective, Antioxidant Mechanism J. Biol. Chem., August 3, 2007; 282(31): 22605 - 22618. [Abstract] [Full Text] [PDF]