In this article, we found that 20-Hydroxyeicosatetraenoic acid (20-HETE) reduced Na/K-ATPase α1 expression via the ubiquitin-proteasome pathway. The ubiquitination level of Na/K-ATPase α1 protein was increased in 20-HETE-treated mouse cortical collecting duct cells and the kidney tissues of CYP4F2 transgenic mice. We also demonstrated that 20-HETE-induced high level phosphorylation of Na/K-ATPase α1 was necessary for its ubiquitination.The protein kinase C inhibitor sotrastaurin significantly reduced the phosphorylation of Na/K-ATPase α1 and increased the expression of Na/K-ATPase α1 although 20-HETE stimulus being applied at the same time. Moreover, high level of 20-HETE increased the expression and neddylation of Cullin3,which is an important ubiquitin E3 ligase in kidney. MLN4924, an inhibitor of NEDD8-activating enzyme, inhibited neddylation of Cullin3 and reversed the reduction of Na/K-ATPase α1 expression caused by 20-HETE. Thus, 20-HETE downregulates Na/K-ATPase α1 via the ubiquitination pathway, and phosphorylation of Na/K-ATPase α1 is a prerequisite to ubiquitination. Additionally, 20-HETE regulates Cullin3 expression via neddylation.

在本文中，我们发现 20-羟基二十碳四烯酸 (20-HETE)通过泛素-蛋白酶体途径减少 Na/K-ATPase α1 表达。 20-HETE处理的小鼠皮质集合管细胞和CYP4F2转基因小鼠的肾组织中Na/K-ATPase α1蛋白的泛素化水平增加。我们还证明20-HETE诱导Na/K-ATPase α1的高水平磷酸化对其泛素化是必要的。蛋白激酶C抑制剂sotrastaurin显着降低Na/K-ATPase α1的磷酸化并增加Na/K的表达-ATPase α1，尽管同时应用 20-HETE 刺激。此外，高水平的20-HETE增加了Cullin3的表达和neddylation，Cullin3是肾脏中重要的泛素E3连接酶。 MLN4924 是 NEDD8 激活酶的抑制剂，可抑制 Cullin3 的 neddylation，并逆转 20-HETE 引起的 Na/K-ATPase α1 表达减少。因此，20-HETE通过泛素化途径下调Na/K-ATPase α1，而Na/K-ATPase α1的磷酸化是泛素化的先决条件。此外，20-HETE通过neddylation 调节 Cullin3 表达。