García-Lorenzo Maribel, Zelisko Agnieszka, Jackowski Grzegorz, Funk Christiane
Department of Biochemistry, Umeå University, S-90187, Umeå, Sweden.
Photochem Photobiol Sci. 2005 Dec;4(12):1065-71. doi: 10.1039/b506625e. Epub 2005 Oct 18.
Many factors trigger the degradation of proteins, including changes in environmental conditions, genetic mutations, and limitations in the availability of cofactors. Despite the importance for viability, still very little is known about protein degradation and its regulation. The degradation of the most abundant membrane protein on Earth, the light-harvesting complex of Photosystem II (LHC II), is highly regulated under different environmental conditions, e.g. light stress, to prevent photochemical damage of the reaction center. However, despite major effort to identify the protease/proteases involved in the degradation of the apoproteins of LHC II the molecular details of this important process remain obscure. LHC II belongs to the family of chlorophyll a/b binding proteins (CAB proteins) and is located in the thylakoid membrane of the plant chloroplast. The results of biochemical experiments to isolate and characterize the protease degrading LHC II are summarized here and compared to our own recent finding indicating that a metalloprotease of the FtsH family is involved in this process.
许多因素会引发蛋白质的降解，包括环境条件的变化、基因突变以及辅因子可用性的限制。尽管蛋白质降解对细胞存活至关重要，但人们对其了解仍然很少。地球上最丰富的膜蛋白——光系统II捕光复合物（LHC II）的降解在不同环境条件下（如光胁迫）受到高度调控，以防止反应中心受到光化学损伤。然而，尽管人们付出了巨大努力来鉴定参与LHC II脱辅基蛋白降解的蛋白酶，但这一重要过程的分子细节仍然不清楚。LHC II属于叶绿素a/b结合蛋白（CAB蛋白）家族，位于植物叶绿体的类囊体膜中。本文总结了分离和鉴定降解LHC II的蛋白酶的生化实验结果，并与我们最近的发现进行了比较，结果表明FtsH家族的一种金属蛋白酶参与了这一过程。
