TY - JOUR
T1 - The thylakoid FtsH protease plays a role in the light-induced turnover of the photosystem II D1 protein
AU - Lindahl, Marika
AU - Spetea, Cornelia
AU - Hundal, Torill
AU - Oppenheim, Amos B.
AU - Adam, Zach
AU - Andersson, Bertil
PY - 2000
Y1 - 2000
N2 - The photosystem II reaction center D1 protein is known to turn over frequently. This protein is prone to irreversible damage caused by reactive oxygen species that are formed in the light; the damaged, nonfunctional D1 protein is degraded and replaced by a new copy. However, the proteases responsible for D1 protein degradation remain unknown. In this study, we investigate the possible role of the FtsH protease, an ATP-dependent zinc metalloprotease, during this process. The primary light-induced cleavage product of the D1 protein, a 23-kD fragment, was found to be degraded in isolated thylakoids in the dark during a process dependent on ATP hydrolysis and divalent metal ions, suggesting the involvement of FtsH. Purified FtsH degraded the 23-kD D1 fragment present in isolated photosystem II core complexes, as well as that in thylakoid membranes depleted of endogenous FtsH. In this study, we definitively identify the chloroplast protease acting on the D1 protein during its light-induced turnover. Unlike previously identified membrane-bound substrates for FtsH in bacteria and mitochondria, the 23-kD D1 fragment represents a novel class of FtsH substrate - functionally assembled proteins that have undergone irreversible photooxidative damage and cleavage.
AB - The photosystem II reaction center D1 protein is known to turn over frequently. This protein is prone to irreversible damage caused by reactive oxygen species that are formed in the light; the damaged, nonfunctional D1 protein is degraded and replaced by a new copy. However, the proteases responsible for D1 protein degradation remain unknown. In this study, we investigate the possible role of the FtsH protease, an ATP-dependent zinc metalloprotease, during this process. The primary light-induced cleavage product of the D1 protein, a 23-kD fragment, was found to be degraded in isolated thylakoids in the dark during a process dependent on ATP hydrolysis and divalent metal ions, suggesting the involvement of FtsH. Purified FtsH degraded the 23-kD D1 fragment present in isolated photosystem II core complexes, as well as that in thylakoid membranes depleted of endogenous FtsH. In this study, we definitively identify the chloroplast protease acting on the D1 protein during its light-induced turnover. Unlike previously identified membrane-bound substrates for FtsH in bacteria and mitochondria, the 23-kD D1 fragment represents a novel class of FtsH substrate - functionally assembled proteins that have undergone irreversible photooxidative damage and cleavage.
UR - http://www.scopus.com/inward/record.url?scp=0034031132&partnerID=8YFLogxK
U2 - 10.1105/tpc.12.3.419
DO - 10.1105/tpc.12.3.419
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C2 - 10715327
AN - SCOPUS:0034031132
SN - 1040-4651
VL - 12
SP - 419
EP - 431
JO - Plant Cell
JF - Plant Cell
IS - 3
ER -