Quality control of Photosystem II: Cleavage and aggregation of heat-damaged D1 protein in spinach thylakoids
- 作者：Keisuke Komayama ; Mahbuba Khatoon ; Daichi Takenaka ; Junko Horie ; Amu Yamashita ; Miho Yoshioka ; Yohsuke Nakayama ; Mari Yoshida ; Satoshi Ohira ; Noriko Morita ; et al.
- 关键词：Photosystem II ; D1 protein ; FtsH proteases ; Phosphatases ; Protein aggregation ; Spinach
- 刊名：Biochimica et Biophysica Acta (BBA)/Bioenergetics
- 出版年：2007
- 期刊代码：13_00052728
- 类别：bio
- 出版时间：June 2007
- 卷：1767
- 期：6
- 页码：838-846
- 文件大小：1039 K
摘要
Moderate heat stress (40 °C, 30 min) on spinach thylakoids induced cleavage of the D1 protein, producing an N-terminal 23-kDa fragment, a C-terminal 9-kDa fragment, and aggregation of the D1 protein. A homologue of Arabidopsis FtsH2 protease, which is responsible for degradation of the damaged D1 protein, was abundant in the stroma thylakoids. Two processes occurred in the thylakoids in response to heat stress: dephosphorylation of the D1 protein in the stroma thylakoids, and aggregation of the phosphorylated D1 protein in the grana. Heat stress also induced the release of the extrinsic PsbO, P and Q proteins from Photosystem II, which affected D1 degradation and aggregation significantly. The cleavage and aggregation of the D1 protein appear to be two alternative processes influenced by protein phosphorylation/dephosphorylation, distribution of FtsH, and intactness of the thylakoids.