Turnover of the aggregates and cross-linked products of the D1 protein generated by acceptor-side photoinhibition of photosystem II
Turnover of the aggregates and cross-linked products of the D1 protein generated by acceptor-side photoinhibition of photosystem II
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DOI：
10.1016/s0005-2728(99)00093-6
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发表时间：
1999-11-10
影响因子：
4.3
通讯作者：
Yamamoto, Y
中科院分区：
文献类型：
--
作者：
Ishikawa, Y;Nakatani, E;Yamamoto, Y
已知光系统（PS）II中的反应中心结合蛋白D1在光抑制期间被显著降解。D1蛋白还通过光照与PS II复合物中邻近的多肽共价交联或非共价聚集。本研究采用SDS/尿素-聚丙烯酰胺凝胶电泳和特异性抗体的Western印迹法检测了D1蛋白与另一个反应中心结合蛋白D2（D1/D2）、细胞色素B（559）α亚基（D1/cyt B（559））和触角叶绿素结合蛋白CP 43（D1/CP 43）之间的加合物。在有氧条件下，用弱光和强光（光强：50 - 5000 μ E m（-2）s（-1））分别对菠菜PS Ⅱ膜、类囊体和完整叶绿体进行了观察。这些结果表明，D1蛋白的交联或聚集是一种普遍的现象，发生在体内以及在体外与光损伤的DI蛋白。我们发现D1/D2？D1/cyt B（559）和D1/CP 43加合物对光强度的依赖性不同;即使在弱光照射下也能形成D1/D2异二聚体和D1/cyt B（559），而D1/CP 43聚集体的产生需要强光照。我们还检测到，这些D1加合物被有效地删除，通过添加基质成分，其中可能含有蛋白酶，分子伴侣和相关蛋白。通过二维SDS/尿素-聚丙烯酰胺凝胶电泳，我们发现，几个基质蛋白，包括15 kDa的蛋白质是有效的去除D1/CP43聚集体，并且它们的活性是耐SDS。(C)1999 Elsevier Science B.V.保留所有权利。
It is known that the reaction-center binding protein D1 in photosystem (PS) II is degraded significantly during photoinhibition. The D1 protein also cross-links covalently or aggregates non-covalently with the nearby polypeptides in PS II complexes by illumination. In the present study, we detected the adducts between the D1 protein and the other reaction-center binding protein D2 (D1/D2), the alpha-subunit of cyt b(559) (D1/cyt b(559)), and the antenna chlorophyll-binding protein CP43 (D1/CP43) by SDS/urea-polyacrylamide gel electrophoresis and Western blotting with specific antibodies. The adducts were observed by weak and strong illumination (light intensity: 50-5000 mu E m(-2) s(-1)) of PS II membranes, thylakoids and intact chloroplasts from spinach, under aerobic conditions. These results indicate that the cross-linking or aggregation of the D1 protein is a general phenomenon which occurs in vivo as well as in vitro with photodamaged DI proteins. We found that the formation of the D1/D2? D1/cyt b(559) and D1/CP43 adducts is differently dependent on the light intensity; the D1/D2 heterodimers and D1/cyt b(559) were formed even by illumination with weak light, whereas generation of the D1/CP43 aggregates required strong illumination. We also detected that these D1 adducts were efficiently removed by the addition of stromal components, which may contain proteases, molecular chaperones and the associated proteins. By two-dimensional SDS/urea-polyacrylamide gel electrophoresis, we found that several stromal proteins, including a 15-kDa protein are effective in removing the D1/CP43 aggregates, and that their activity is resistant to SDS. (C) 1999 Elsevier Science B.V. All rights reserved.