Serum- and glucocorticoid-inducible kinase SGK2 regulates human organic anion transporters 4 via ubiquitin ligase Nedd4-2.
Serum- and glucocorticoid-inducible kinase SGK2 regulates human organic anion transporters 4 via ubiquitin ligase Nedd4-2.
复制标题
DOI：
10.1016/j.bcp.2015.11.024
复制
发表时间：
2016-02-15
影响因子：
5.8
通讯作者：
You, Guofeng
中科院分区：
文献类型：
--
作者：
Wang, Haoxun;Xu, Da;Toh, May Fern;Pao, Alan C.;You, Guofeng
关键词：
人有机阴离子转运蛋白4（human organic anion transporter 4，hOAT 4）属于有机阴离子转运蛋白家族，在抗病毒药物、抗癌药物、抗生素、抗高血压药物和抗炎药物等临床重要药物的体内分布中发挥重要作用。hOAT 4在肾脏和胎盘中大量表达。在目前的研究中，我们研究了在肾脏COS-7细胞中血清和糖皮质激素诱导的激酶2（sgk 2）对hOAT 4的调节。我们发现sgk 2刺激hOAT 4转运活性。这种刺激主要是由于增加的细胞表面表达的转运蛋白，动力学上显示为增加的最大运输速度Vmax，而没有显着变化的底物结合亲和力Km。我们进一步表明sgk 2对hOAT 4活性的调节是由泛素连接酶Nedd 4 -2介导的。过表达Nedd 4 -2增强hOAT 4泛素化，抑制hOAT 4转运活性，而过表达泛素连接酶死亡突变体Nedd 4 -2/C821 A或siRNA敲低内源性Nedd 4 -2对hOAT 4有相反的作用。我们的免疫共沉淀实验表明，sgk 2减弱了hOAT 4和Nedd 4 -2之间的关联。总之，我们的研究首次证明sgk 2通过消除Nedd 4 -2对转运蛋白的抑制作用来刺激hOAT 4转运活性。
Human organic anion transporter 4 (hOAT4) belongs to a family of organic anion transporters that play critical roles in the body disposition of clinically important drugs, including anti-viral therapeutics, anti-cancer drugs, antibiotics, antihypertensives, and anti-inflammatories. hOAT4 is abundantly expressed in the kidney and placenta. In the current study, we examined the regulation of hOAT4 by serum- and glucocorticoid-inducible kinase 2 (sgk2) in the kidney COS-7 cells. We showed that sgk2 stimulated hOAT4 transport activity. Such stimulation mainly resulted from an increased cell surface expression of the transporter, kinetically revealed as an increased maximal transport velocity Vmax without significant change in substrate-binding affinity Km. We further showed that regulation of hOAT4 activity by sgk2 was mediated by ubiquitin ligase Nedd4-2. Overexpression of Nedd4-2 enhanced hOAT4 ubiquitination, and inhibited hOAT4 transport activity, whereas overexpression of ubiquitin ligase-dead mutant Nedd4-2/C821A or siRNA knockdown of endogenous Nedd4-2 had opposite effects on hOAT4. Our co-immunoprecipitation experiment revealed that sgk2 weakened the association between hOAT4 and Nedd4-2. In conclusion, our study demonstrated for the first time that sgk2 stimulated hOAT4 transport activity by abrogating the inhibition effect of Nedd4-2 on the transporter.
登录
查看更多内容
影响因子：
4
作者：
Rotin D;Staub O
通讯作者：
Staub O
DOI：
10.1073/pnas.96.5.2514
发表时间：
1999-03-02
影响因子：
11.1
作者：
Chen, SY;Bhargava, A;Pearce, D
通讯作者：
Pearce, D
影响因子：
5.3
作者：
Sorkina, Tatiana;Miranda, Manuel;Sorkin, Alexander
通讯作者：
Sorkin, Alexander
DOI：
10.1152/ajplung.2002.282.1.l12
发表时间：
2002-01-01
影响因子：
4.9
作者：
Cobb, BR;Ruiz, F;Clancy, JP
通讯作者：
Clancy, JP
DOI：
10.1152/ajprenal.00075.2010
发表时间：
2010-12-01
影响因子：
4.2
作者：
Pao, Alan C.;Bhargava, Aditi;Pearce, David
通讯作者：
Pearce, David