Graduate Institute of Life Sciences, National Defense Medical Center, Taipei, Taiwan.
Plant Signal Behav. 2012 Sep 1;7(9):1082-3. doi: 10.4161/psb.21147. Epub 2012 Aug 17.
In a previous study, we demonstrated that Arabidopsis Antioxidant Protein1 (ATX1) plays an essential role in copper (Cu) homeostasis, conferring tolerance to both excess and subclinically deficient Cu. The Cu-binding motif MXCXXC was required for the physiological function of ATX1. In this study, we found that overexpression of ATX1 resulted in hypersensitivity to severe Cu deficiency despite enhancing tolerance to subclinical Cu deficiency. However, overexpression of mutated ATX1, replacing the Cu-binding motif MXCXXC with MXGXXG, abolished the hypersensitivity, for no differences from the wild type under the same conditions. Thus, the expression of ATX1 must be cautiously regulated to avoid homeostatic imbalance with the over-chelation of Cu.
在之前的研究中，我们证明了拟南芥抗氧化蛋白 1（ATX1）在铜（Cu）稳态中发挥着重要作用，使其能够耐受过量和亚临床缺乏的 Cu。Cu 结合基序 MXCXXC 是 ATX1 生理功能所必需的。在这项研究中，我们发现尽管 ATX1 的过表达增强了对亚临床 Cu 缺乏的耐受性，但仍导致对严重 Cu 缺乏的敏感性增加。然而，过表达突变的 ATX1，将 Cu 结合基序 MXCXXC 替换为 MXGXXG，消除了敏感性，在相同条件下与野生型没有差异。因此，必须谨慎调节 ATX1 的表达，以避免 Cu 的过度螯合导致的体内平衡失调。
