Aro E-M, Suorsa M, Rokka A, Allahverdiyeva Y, Paakkarinen V, Saleem A, Battchikova N, Rintamäki E
Department of Biology, University of Turku, FIN-20014 Turku, Finland.
J Exp Bot. 2005 Jan;56(411):347-56. doi: 10.1093/jxb/eri041. Epub 2004 Nov 29.
Oxygenic photosynthesis produces various radicals and active oxygen species with harmful effects on photosystem II (PSII). Such photodamage occurs at all light intensities. Damaged PSII centres, however, do not usually accumulate in the thylakoid membrane due to a rapid and efficient repair mechanism. The excellent design of PSII gives protection to most of the protein components and the damage is most often targeted only to the reaction centre D1 protein. Repair of PSII via turnover of the damaged protein subunits is a complex process involving (i) highly regulated reversible phosphorylation of several PSII core subunits, (ii) monomerization and migration of the PSII core from the grana to the stroma lamellae, (iii) partial disassembly of the PSII core monomer, (iv) highly specific proteolysis of the damaged proteins, and finally (v) a multi-step replacement of the damaged proteins with de novo synthesized copies followed by (vi) the reassembly, dimerization, and photoactivation of the PSII complexes. These processes will shortly be reviewed paying particular attention to the damage, turnover, and assembly of the PSII complex in grana and stroma thylakoids during the photoinhibition-repair cycle of PSII. Moreover, a two-dimensional Blue-native gel map of thylakoid membrane protein complexes, and their modification in the grana and stroma lamellae during a high-light treatment, is presented.
氧光合作用会产生各种对光系统II（PSII）有有害影响的自由基和活性氧物种。这种光损伤在所有光照强度下都会发生。然而，由于快速且高效的修复机制，受损的PSII中心通常不会在类囊体膜中积累。PSII的出色设计保护了大多数蛋白质成分，损伤通常仅针对反应中心D1蛋白。通过受损蛋白质亚基的周转来修复PSII是一个复杂的过程，涉及（i）几个PSII核心亚基的高度调控的可逆磷酸化，（ii）PSII核心从基粒向基质类囊体的单体化和迁移，（iii）PSII核心单体的部分拆卸，（iv）受损蛋白质的高度特异性蛋白水解，最后（v）用新合成的拷贝对受损蛋白质进行多步替换，随后（vi）PSII复合物的重新组装、二聚化和光激活。这些过程将在本文中进行简要综述，特别关注PSII光抑制 - 修复循环过程中基粒和基质类囊体中PSII复合物的损伤、周转和组装。此外，本文还展示了类囊体膜蛋白复合物的二维蓝色非变性凝胶图谱，以及高光处理过程中它们在基粒和基质类囊体中的修饰情况。
