TY - JOUR
T1 - Quality control of Photosystem II
T2 - Where and how does the degradation of the D1 protein by FtsH proteases start under light stress? - Facts and hypotheses
AU - Yoshioka, Miho
AU - Yamamoto, Yasusi
N1 - Funding Information:
We thank Ms. Noriko Morita for preparing figures and Drs. Yuichiro Takahashi, Jian-Ren Shen, Hideki Kobayashi, Norikazu Ohnishi, Björn Lundin of Okayama University for valuable discussion. This work was supported by a Grant-in-Aid for Scientific Research ( Grant Number 20570039 ) from the Ministry of Education, Culture, Sports, Science and Technology of Japan to Y.Y., and grants for the Okayama University Woman-Tenure-Track (WTT) Staff from Okayama University, from The Japan Science Society (The Sasakawa Scientific Research Grant), from the Ryobi Foundation, and from the Nippon Life Insurance Foundation to M.Y.
PY - 2011/7
Y1 - 2011/7
N2 - Degradation of the reaction center-binding D1 protein of Photosystem II is central in photoinhibition of Photosystem II. In higher plant chloroplasts, Photosystem II complexes are abundant in the grana. It has been suggested that the Photosystem II complexes containing photodamaged D1 protein migrate for their repair from the grana to the non-appressed stroma thylakoids, where the photodamaged D1 protein is degraded by a specific protease(s) such as filamentation temperature sensitive H (FtsH) protease. There are several possible ways to activate the FtsH proteases. As FtsH is a membrane-bound ATP-dependent metalloprotease, it requires ATP and zinc as essential part of its catalytic mechanism. It is also suggested that a membrane protein(s) associated with FtsH is required for modulation of the FtsH activity. Here, we propose several possible mechanisms for activation of the proteases, which depend on oligomerization of the monomer subunits. In relation to the oligomerization of FtsH subunits, we also suggest unique distribution of active FtsH hexamers on the thylakoids: hexamers of the FtsH proteases are localized near the Photosystem II complexes at the grana. Degradation of the D1 protein probably takes place in the grana rather than in the stroma thylakoids to circumvent long-distance migration of both the Photosystem II complexes containing the photodamaged D1 protein and the proteases.
AB - Degradation of the reaction center-binding D1 protein of Photosystem II is central in photoinhibition of Photosystem II. In higher plant chloroplasts, Photosystem II complexes are abundant in the grana. It has been suggested that the Photosystem II complexes containing photodamaged D1 protein migrate for their repair from the grana to the non-appressed stroma thylakoids, where the photodamaged D1 protein is degraded by a specific protease(s) such as filamentation temperature sensitive H (FtsH) protease. There are several possible ways to activate the FtsH proteases. As FtsH is a membrane-bound ATP-dependent metalloprotease, it requires ATP and zinc as essential part of its catalytic mechanism. It is also suggested that a membrane protein(s) associated with FtsH is required for modulation of the FtsH activity. Here, we propose several possible mechanisms for activation of the proteases, which depend on oligomerization of the monomer subunits. In relation to the oligomerization of FtsH subunits, we also suggest unique distribution of active FtsH hexamers on the thylakoids: hexamers of the FtsH proteases are localized near the Photosystem II complexes at the grana. Degradation of the D1 protein probably takes place in the grana rather than in the stroma thylakoids to circumvent long-distance migration of both the Photosystem II complexes containing the photodamaged D1 protein and the proteases.
KW - D1 protein
KW - FtsH protease
KW - Light stress
KW - Photosystem II
KW - Thylakoid unstacking
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U2 - 10.1016/j.jphotobiol.2011.01.016
DO - 10.1016/j.jphotobiol.2011.01.016
M3 - Review article
C2 - 21333546
AN - SCOPUS:79957977244
VL - 104
SP - 229
EP - 235
JO - Journal of Photochemistry and Photobiology B: Biology
JF - Journal of Photochemistry and Photobiology B: Biology
SN - 1011-1344
IS - 1-2
ER -