Members of the g protein-coupled receptor kinase family that phosphorylate the beta(2)-adrenergic receptor facilitate sequestration
Members of the g protein-coupled receptor kinase family that phosphorylate the beta(2)-adrenergic receptor facilitate sequestration
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DOI：
10.1021/bi952961
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发表时间：
1996-04-02
期刊：
影响因子：
2.9
通讯作者：
Caron, MG
中科院分区：
文献类型：
--
作者：
Menard, L;Ferguson, SSG;Caron, MG
我们最近报道了一种β 2肾上腺素能受体（β 2 AR）突变体Y326 A，它在激动剂刺激下的螯合能力有缺陷，是G蛋白偶联受体激酶（GRK）介导的磷酸化的不良底物;然而，其被磷酸化和螯合的能力可以通过过表达GRK 2而恢复[Ferguson等（1995）J.Biol.Chem.270，24782]。在本报告中，我们测试了每种已知GRK（GRK 1 -6）磷酸化和拯救HEK-293细胞中Y326 A突变体的螯合的能力。我们证明，除了GRK 2，GRK 3 -6可以磷酸化的Y326 A突变体和拯救其隔离，然而，GRK 1是完全无效的拯救无论是磷酸化或隔离的突变体受体。我们发现GRK 2、GRK 3和GRK 5对Y326 A突变体磷酸化的激动剂依赖性拯救与螯合的激动剂依赖性拯救相关。相反，GRK 4和GRK 6的过表达主要导致Y326 A突变体的激动剂非依赖性磷酸化，伴随着基础受体螯合的增加。我们的研究结果表明，磷酸化本身，而不是与特定的GRK的相互作用，是促进β（2）AR螯合所必需的。
We recently reported that a beta(2)-adrenergic receptor (beta(2)AR) mutant, Y326A, defective in its ability to sequester in response to agonist stimulation was a poor substrate for G protein-coupled receptor kinase (GRK)-mediated phosphorylation; however, its ability to be phosphorylated and sequestered could be restored by overexpressing GRK2 [Ferguson et al. (1995) J. Biol. Chem. 270, 24782]. In the present report, we tested the ability of each of the known GRKs (GRK1-6) to phosphorylate and rescue the sequestration of the Y326A mutant in HEK-293 cells. We demonstrate that in addition to GRK2, GRK3-6 can phosphorylate the Y326A mutant and rescue its sequestration; however, GRK1 was totally ineffective in rescuing either the phosphorylation or the sequestration of the mutant receptor. We found that the agonist-dependent rescue of Y326A mutant phosphorylation by GRK2, -3, and -5 was associated with the agonist-dependent rescue of sequestration. In contrast, overexpression of GRK4 and -6 led mainly to agonist-independent phosphorylation of the Y326A mutant accompanied by increased basal receptor sequestration. Our results demonstrate that phosphorylation per se, but not the interaction with a specific GRK, is required to facilitate beta(2)AR sequestration.