Mulo Paula, Sicora Cosmin, Aro Eva-Mari
Laboratory of Plant Physiology and Molecular Biology, Department of Biology, Biocity A, University of Turku, 20520 Turku, Finland.
Cell Mol Life Sci. 2009 Dec;66(23):3697-710. doi: 10.1007/s00018-009-0103-6. Epub 2009 Jul 31.
The D1 protein of Photosystem II (PSII), encoded by the psbA genes, is an indispensable component of oxygenic photosynthesis. Due to strongly oxidative chemistry of PSII water splitting, the D1 protein is prone to constant photodamage requiring its replacement, whereas most of the other PSII subunits remain ordinarily undamaged. In cyanobacteria, the D1 protein is encoded by a psbA gene family, whose members are differentially expressed according to environmental cues. Here, the regulation of the psbA gene expression is first discussed with emphasis on the model organisms Synechococcus sp. and Synechocystis sp. Then, a general classification of cyanobacterial D1 isoforms in various cyanobacterial species into D1m, D1:1, D1:2, and D1' forms depending on their expression pattern under acclimated growth conditions and upon stress is discussed, taking into consideration the phototolerance of different D1 forms and the expression conditions of respective members of the psbA gene family.
光系统II（PSII）的D1蛋白由psbA基因编码，是产氧光合作用不可或缺的组成部分。由于PSII水裂解的强氧化化学性质，D1蛋白容易受到持续的光损伤而需要被替换，而大多数其他PSII亚基通常保持未受损状态。在蓝细菌中，D1蛋白由一个psbA基因家族编码，其成员根据环境线索进行差异表达。在此，首先讨论psbA基因表达的调控，重点是模式生物聚球藻属和集胞藻属。然后，根据不同蓝细菌物种在适应生长条件下和应激时的表达模式，将蓝细菌中各种蓝细菌物种的D1同工型大致分为D1m、D1:1、D1:2和D1'形式，同时考虑不同D1形式的光耐受性以及psbA基因家族各成员的表达条件。
