ULK1 Phosphorylates and Regulates Mineralocorticoid Receptor
ULK1 Phosphorylates and Regulates Mineralocorticoid Receptor
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ULK1 磷酸化并调节盐皮质激素受体
DOI：
10.1016/j.celrep.2018.06.072
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发表时间：
2018
期刊：
影响因子：
8.8
通讯作者：
Lifton Richard P.
中科院分区：
文献类型：
--
作者：
Shibata Shigeru;Ishizawa Kenichi;Wang Qin;Xu Ning;Fujita Toshiro;Uchida Shunya;Lifton Richard P.
矿盐皮质激素受体（MR）信号传导调节肾脏Na-Cl重吸收和K+排泄。我们之前证明了肾插层细胞MR配体结合区域的S843磷酸化通过调节配体结合和信号传导参与了这些活动的平衡。然而，磷酸化mrs843的激酶是未知的。通过对197种激酶的高通量筛选，我们发现ULK1是MRS843磷酸化的主要激酶。该结果通过蛋白激酶测定、质谱分析和siRNA敲低实验得到证实。值得注意的是，在ULK1/2双敲除小鼠胚胎成纤维细胞中，mrs843的磷酸化显著降低。在上游，我们发现ULK1活性在细胞培养和体内被血管紧张素II通过mTOR诱导的磷酸化所抑制。这些发现暗示mTOR和ULK1是嵌入细胞中MR活性的调节因子，这是维持电解质稳态的关键途径。
Mineralocorticoid receptor (MR) signaling regulates both renal Na-Cl reabsorption and K+excretion. We previously demonstrated that phosphorylation of S843 in the MR ligand-binding domain in renal intercalated cells is involved in the balance of these activities by regulating ligand binding and signaling. However, the kinase that phosphorylates MRS843is unknown. Using a high-throughput screen assay of 197 kinases, we found that ULK1 is the principal kinase that is responsible for the phosphorylation of MRS843. The results were confirmed byin vitrokinase assay, mass spectrometry, and siRNA knockdown experiments. Notably, phosphorylation at MRS843was markedly reduced in ULK1/2 double knockout mouse embryonic fibroblasts. Upstream, we show that ULK1 activity is inhibited by phosphorylation induced by angiotensin II via mTOR in cell culture andin vivo. These findings implicate mTOR and ULK1 as regulators of MR activity in intercalated cells, a pathway that is critical for maintaining electrolyte homeostasis.