Modulation of neurosteroid potentiation by protein kinases at synaptic- and extrasynaptic-type GABAA receptors.
Modulation of neurosteroid potentiation by protein kinases at synaptic- and extrasynaptic-type GABAA receptors.
复制标题
DOI：
10.1016/j.neuropharm.2014.09.021
复制
发表时间：
2015-01
影响因子：
4.7
通讯作者：
Smart TG
中科院分区：
文献类型：
--
作者：
Adams JM;Thomas P;Smart TG
GABAA受体对于CNS中的抑制作用是重要的，其中神经类固醇和蛋白激酶是有效的内源性调节剂。单独作用，这些可以增强或抑制受体功能，这取决于神经类固醇或激酶的类型和受体亚基组合。然而，在体内，这些调节剂可能共同作用以微调GABAA受体活性并因此抑制，尽管这是如何实现的仍不清楚。因此，我们使用电生理学研究了突触型α1β3γ2L和突触外型α4β3δ GABAA受体的这些调节剂之间的关系。对于α1β3γ2L，四氢脱氧皮质酮增强GABA反应在抑制蛋白激酶C后减少，并在其激活后增强，表明该激酶调节神经类固醇调节。相比之下，神经类固醇增强作用在α1β3S408A、S409Aγ2L受体处降低，并且不受PKC抑制剂或激活剂的影响，表明β3亚基的磷酸化对于调节神经类固醇活性是重要的。为了确定突触外型GABAA受体是否受到类似的调节，研究了α4β3δ和α4β 3 S408 A、S409 A δ受体。激酶抑制剂staurosporine在两种受体上都降低了神经类固醇的增强作用。相比之下，α4S443Aβ3S408A、S409Aδ受体的神经类固醇介导的增强作用不受蛋白激酶抑制的影响，这强烈表明α4和β3亚基的磷酸化是调节突触外受体的神经类固醇活性所必需的。Western blot分析显示，神经甾体可增加β3S408、S409的磷酸化，提示神经甾体调节GABAA受体磷酸化存在相互作用的途径。总体而言，这些发现提供了重要的洞察GABAA受体在体内的调节，并进入GABA能抑制性传输的机制，可以同时调谐两种内源性神经调质。这篇文章是题为“健康和疾病中的GABA能信号”的特刊的一部分。GABAA受体的神经类固醇增强作用受蛋白激酶活性调节。突触型α1β3γ2L受体增强受PKC活性的上调或下调。PKC介导的调节通过β3亚基S408和S409磷酸化发生。突触外型α4β3δ受体的增强作用还受α4S443的调节。神经甾体通过β S408、S409促进GABAA受体的磷酸化。
GABAA receptors are important for inhibition in the CNS where neurosteroids and protein kinases are potent endogenous modulators. Acting individually, these can either enhance or depress receptor function, dependent upon the type of neurosteroid or kinase and the receptor subunit combination. However, in vivo, these modulators probably act in concert to fine-tune GABAA receptor activity and thus inhibition, although how this is achieved remains unclear. Therefore, we investigated the relationship between these modulators at synaptic-type α1β3γ2L and extrasynaptic-type α4β3δ GABAA receptors using electrophysiology. For α1β3γ2L, potentiation of GABA responses by tetrahydro-deoxycorticosterone was reduced after inhibiting protein kinase C, and enhanced following its activation, suggesting this kinase regulates neurosteroid modulation. In comparison, neurosteroid potentiation was reduced at α1β3S408A,S409Aγ2L receptors, and unaltered by PKC inhibitors or activators, indicating that phosphorylation of β3 subunits is important for regulating neurosteroid activity. To determine whether extrasynaptic-type GABAA receptors were similarly modulated, α4β3δ and α4β3S408A,S409Aδ receptors were investigated. Neurosteroid potentiation was reduced at both receptors by the kinase inhibitor staurosporine. By contrast, neurosteroid-mediated potentiation at α4S443Aβ3S408A,S409Aδ receptors was unaffected by protein kinase inhibition, strongly suggesting that phosphorylation of α4 and β3 subunits is required for regulating neurosteroid activity at extrasynaptic receptors. Western blot analyses revealed that neurosteroids increased phosphorylation of β3S408,S409 implying that a reciprocal pathway exists for neurosteroids to modulate phosphorylation of GABAA receptors. Overall, these findings provide important insight into the regulation of GABAA receptors in vivo, and into the mechanisms by which GABAergic inhibitory transmission may be simultaneously tuned by two endogenous neuromodulators. This article is part of the Special Issue entitled ‘GABAergic Signaling in Health and Disease’. Neurosteroid potentiation at GABAA receptors is modulated by protein kinase activity. Synaptic-type α1β3γ2L receptor potentiation is up or down-regulated by PKC activity. PKC-mediated modulation occurs via β3 subunit S408 & S409 phosphorylation. Potentiation at extrasynaptic-type α4β3δ receptors is additionally regulated by α4S443. Neurosteroids facilitate phosphorylation of GABAA receptors via βS408,S409.
登录
查看更多内容
影响因子：
5.3
作者：
Jovanovic, JN;Thomas, P;Moss, SJ
通讯作者：
Moss, SJ
影响因子：
4.8
作者：
Connolly, CN;Krishek, BJ;Moss, SJ
通讯作者：
Moss, SJ
影响因子：
4.8
作者：
Brandon, NJ;Delmas, P;Moss, SJ
通讯作者：
Moss, SJ
影响因子：
4.7
作者：
Harney, SC;Frenguelli, BG;Lambert, JJ
通讯作者：
Lambert, JJ
影响因子：
5.5
作者：
Mortensen, Martin;Ebert, Bjarke;Smart, Trevor G.
通讯作者：
Smart, Trevor G.