Protein kinase C and cAMP-dependent protein kinase phosphorylate the beta subunit of the purified gamma-aminobutyric acid A receptor.
Protein kinase C and cAMP-dependent protein kinase phosphorylate the beta subunit of the purified gamma-aminobutyric acid A receptor.
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蛋白激酶 C 和 cAMP 依赖性蛋白激酶使纯化的 γ-氨基丁酸 A 受体的 β 亚基磷酸化。
DOI：
10.1073/pnas.87.4.1315
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发表时间：
1990
影响因子：
11.1
通讯作者：
Olsen,RW
中科院分区：
文献类型：
--
作者：
Browning,MD;Bureau,M;Dudek,EM;Olsen,RW
最近的一些研究表明，γ-氨基丁酸A(GABAA)受体的磷酸化可以调节受体的功能。蛋白激酶C和cAMP依赖的蛋白激酶的激活剂已被证明影响GABAA受体的功能。此外，Sweetnam et al.首页--期刊主要分类--期刊细介绍--期刊题录与文摘--期刊详细文摘内容51,1274-1284]已经报道，与部分纯化的受体制剂相关的激酶可以使受体的阿尔法亚单位磷酸化。此外，Kirkness et al.书名/作者声明：Reach of[J][J.J.259,613-616]最近发现，cAMP依赖的蛋白激酶可以磷酸化GABAA受体的一种蝇醇结合多肽。为了进一步探讨这个问题，我们检测了特定的激酶催化GABAA受体显著磷酸化的能力，该受体已被纯化到接近均一的水平。如前所述，使用苯二氮卓类亲和层析纯化了GABAA受体。纯化的受体没有检测到的激酶活性。蛋白激酶C和cAMP依赖的蛋白激酶催化受体的β和α亚基的磷酸化。然而，大部分的磷酸掺入与β亚基有关。该制剂中含有两种蝇草醇结合多肽，分别命名为β58(Mr 58,000)和β56(Mr 56,000)。相对分子质量较高的多肽β58被cAMP依赖的蛋白激酶特异性地磷酸化。β56被蛋白激酶C特异性地磷酸化，β58和β56在一维磷酸肽分析中给出了不同的模式。CAMP依赖的蛋白激酶催化磷酸化的化学计量比为0.52，蛋白激酶C催化的磷酸化的化学计量比为0.38。综上所述，这些数据证实了GABAA受体的β亚基有两种形式，并表明这两种形式的β亚基是由不同的激酶磷酸化的。
A number of recent studies have suggested that phosphorylation of the gamma-aminobutyric acid A (GABAA) receptor could modulate receptor function. Activators of protein kinase C and cAMP-dependent protein kinase have been shown to influence GABAA receptor function. In addition, Sweetnam et al. [Sweetnam, P. M., Lloyd, J., Gallombardo, P., Malison, R. T., Gallager, D. W., Tallman, J. F. & Nestler, E. J. (1988) J. Neurochem. 51, 1274-1284] have reported that a kinase associated with a partially purified preparation of the receptor could phosphorylate the alpha subunit of the receptor. Moreover, Kirkness et al. [Kirkness, E. F., Bovenkerk, C. F., Ueda, T. & Turner, A. J. (1989) Biochem. J. 259, 613-616] have recently shown that cAMP-dependent protein kinase could phosphorylate a muscimol binding polypeptide of the GABAA receptor. To explore the issue further, we have examined the ability of specific kinases to catalyze significant phosphorylation of the GABAA receptor that has been purified to near homogeneity. The GABAA receptor was purified as previously described using benzodiazepine affinity chromatography. The purified receptor possessed no detectable kinase activity. Protein kinase C and cAMP-dependent protein kinase catalyzed the phosphorylation of the beta and alpha subunits of the receptor. However, most of the phosphate incorporation was associated with the beta subunit. Two muscimol binding polypeptides designated beta 58 (Mr 58,000) and beta 56 (Mr 56,000) were present in the preparation. The higher molecular weight polypeptide, beta 58, was phosphorylated specifically by cAMP-dependent protein kinase. beta 56 was phosphorylated specifically by protein kinase C. beta 58 and beta 56 gave distinct patterns in a one-dimensional phosphopeptide analysis. The stoichiometry of phosphorylation (mol of phosphate/mol of muscimol binding) catalyzed by cAMP-dependent protein kinase was 0.52 and that catalyzed by protein kinase C was 0.38. Taken together these data confirm that there are two forms of the beta subunit of the GABAA receptor and suggest that these two forms of the beta subunit are phosphorylated by distinct kinases.