Johansson Elin, Olsson Olof, Nyström Thomas
Department of Cell and Molecular Biology, Göteborg University, Box 462, 405 30 Göteborg, Sweden.
J Biol Chem. 2004 May 21;279(21):22204-8. doi: 10.1074/jbc.M402652200. Epub 2004 Apr 7.
Protein carbonylation is an irreversible oxidative process leading to a loss of function of the modified proteins, and in a variety of model systems, including worms, flies, and mammals, carbonyl levels gradually increase with age. In contrast, we report here that in Arabidopsis thaliana an initial increase in protein oxidation during the first 20 days of the life cycle of the plant is followed by a drastic reduction in protein carbonyls prior to bolting and flower development. Protein carbonylation prior to the transition to flowering targets specific proteins such as Hsp70, ATP synthases, the large subunit of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco), and proteins involved in light harvesting/energy transfer and the C2 oxidative photosynthetic carbon cycle. The precipitous fall in protein carbonyl levels is due to the specific reduction in the levels of oxidized proteins rather than an overall loss of chlorophyll and Rubisco associated with the senescence syndrome. The results are discussed in light of contemporary theories of aging in animals.
蛋白质羰基化是一个不可逆的氧化过程，会导致被修饰蛋白质功能丧失。在包括线虫、果蝇和哺乳动物在内的多种模型系统中，羰基水平会随着年龄增长而逐渐升高。相比之下，我们在此报告，在拟南芥中，植物生命周期的前20天蛋白质氧化最初会增加，随后在抽薹和花发育之前蛋白质羰基含量会急剧下降。向开花转变之前的蛋白质羰基化作用于特定蛋白质，如热休克蛋白70、ATP合酶、1,5-二磷酸核酮糖羧化酶/加氧酶（Rubisco）的大亚基，以及参与光捕获/能量转移和C2氧化光合碳循环的蛋白质。蛋白质羰基水平的急剧下降是由于氧化蛋白质水平的特异性降低，而非与衰老综合征相关的叶绿素和Rubisco的整体损失。我们根据当代动物衰老理论对这些结果进行了讨论。
