Agricultural Biotechnology Research Center, Academia Sinica, Taipei, Taiwan.
Plant Signal Behav. 2011 Oct;6(10):1428-30. doi: 10.4161/psb.6.10.16933. Epub 2011 Oct 1.
In a previous study, we found copper (Cu) accumulated to a higher level in the aerial parts of soil-grown plants of the SUMO E3 ligase siz1 mutant than in those of the wild type. Here, we found that all superoxide dismutase (SOD) isoforms, such as FeSOD, MnSOD and different types of Cu/ZnSOD, were more active in the siz1 mutant than in the wild type under normal growth conditions. We further examined the expression and enzymatic activity of Cu/ZnSOD1 (CSD1) in shoots of the siz1 mutant under excess Cu. Shoot CSD1 protein level and activity were reduced in siz1 with excess Cu but induced in the wild type. SIZ1-dependent SUMOylation may be involved in maintaining CSD1 protein stability or repelling a feedback regulation under Cu stress.
在之前的一项研究中，我们发现与野生型相比，SUMO E3 连接酶 siz1 突变体在土壤中生长的植物地上部分积累了更高水平的铜（Cu）。在这里，我们发现所有超氧化物歧化酶（SOD）同工酶，如 FeSOD、MnSOD 和不同类型的 Cu/ZnSOD，在正常生长条件下，突变体中的活性均高于野生型。我们进一步研究了在过量 Cu 下 siz1 突变体中 Cu/ZnSOD1（CSD1）的表达和酶活性。在含有过量 Cu 的 siz1 中，CSD1 蛋白水平和活性降低，但在野生型中诱导。SIZ1 依赖性 SUMO 化可能参与维持 CSD1 蛋白稳定性或在 Cu 胁迫下排斥反馈调节。
