Department of Animal Science, Cornell University, Ithaca, NY 14853, USA.
Int J Mol Sci. 2023 Feb 6;24(4):3230. doi: 10.3390/ijms24043230.
Copper-zinc superoxide dismutase 1 (SOD1) has long been recognized as a major redox enzyme in scavenging superoxide radicals. However, there is little information on its non-canonical role and metabolic implications. Using a protein complementation assay (PCA) and pull-down assay, we revealed novel protein-protein interactions (PPIs) between SOD1 and tyrosine 3-monooxygenase/tryptophan 5-monooxygenase activation protein zeta (YWHAZ) or epsilon (YWHAE) in this research. Through site-directed mutagenesis of SOD1, we studied the binding conditions of the two PPIs. Forming the SOD1 and YWHAE or YWHAZ protein complex enhanced enzyme activity of purified SOD1 in vitro by 40% ( < 0.05) and protein stability of over-expressed intracellular YWHAE (18%, < 0.01) and YWHAZ (14%, < 0.05). Functionally, these PPIs were associated with lipolysis, cell growth, and cell survival in HEK293T or HepG2 cells. In conclusion, our findings reveal two new PPIs between SOD1 and YWHAE or YWHAZ and their structural dependences, responses to redox status, mutual impacts on the enzyme function and protein degradation, and metabolic implications. Overall, our finding revealed a new unorthodox role of SOD1 and will provide novel perspectives and insights for diagnosing and treating diseases related to the protein.
铜锌超氧化物歧化酶 1（SOD1）长期以来一直被认为是清除超氧自由基的主要氧化还原酶。然而，关于其非典型作用和代谢意义的信息很少。在这项研究中，我们使用蛋白质互补测定（PCA）和下拉测定揭示了 SOD1 与酪氨酸 3-单加氧酶/色氨酸 5-单加氧酶激活蛋白 ζ（YWHAZ）或 ε（YWHAE）之间新的蛋白质-蛋白质相互作用（PPIs）。通过 SOD1 的定点突变，我们研究了这两个 PPIs 的结合条件。形成 SOD1 和 YWHAE 或 YWHAZ 蛋白复合物可使体外纯化的 SOD1 酶活性提高 40%（ < 0.05），并使过表达的细胞内 YWHAE（18%， < 0.01）和 YWHAZ（14%， < 0.05）的蛋白稳定性提高。功能上，这些 PPIs 与 HEK293T 或 HepG2 细胞中的脂肪分解、细胞生长和细胞存活有关。总之，我们的研究结果揭示了 SOD1 与 YWHAE 或 YWHAZ 之间的两个新的 PPIs 及其结构依赖性、对氧化还原状态的反应、对酶功能和蛋白降解的相互影响，以及代谢意义。总的来说，我们的发现揭示了 SOD1 的一个新的非传统作用，并为诊断和治疗与该蛋白相关的疾病提供了新的视角和见解。
