Modulation of GABAA receptor phosphorylation and membrane trafficking by phospholipase C-related inactive protein/protein phosphatase 1 and 2A signaling complex underlying brain-derived neurotrophic factor-dependent regulation of GABAergic inhibition
Modulation of GABAA receptor phosphorylation and membrane trafficking by phospholipase C-related inactive protein/protein phosphatase 1 and 2A signaling complex underlying brain-derived neurotrophic factor-dependent regulation of GABAergic inhibition
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DOI：
10.1074/jbc.m603118200
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发表时间：
2006-08-04
影响因子：
4.8
通讯作者：
Hirata, Masato
中科院分区：
文献类型：
--
作者：
Kanematsu, Takashi;Yasunaga, Atsushi;Hirata, Masato
脑源性神经营养因子(BDNF)调节突触传递的几个不同方面，包括GABA能传递。暴露于BDNF可改变GABA(A)受体的特性，并诱导细胞表面表达水平的变化。虽然磷脂酶C相关失活蛋白-1(PRIP-1)在GABA(A)受体的转运和功能中起着重要的作用，但我们用培养的PRIP-2双基因敲除小鼠神经元，研究了PRIP-1在BDNF依赖的调节这些受体中的作用。在野生型神经元中观察到的BDNF依赖的全细胞GABA诱发电流的抑制在从基因敲除小鼠培养的神经元中没有检测到。相反，这些神经元中GABA诱发电流的逐渐增加与对BDNF的反应中GABA(A)受体β3亚单位的磷酸化逐渐增加有关。为了确定蛋白磷酸酶作为潜在分子机制组件的特殊作用(S)，我们研究了蛋白磷酸酶(S)对氨基丁酸(A)受体的募集。我们证明了PRIP与磷酸酶以及β亚基有关。在培养的神经元中，Prip与GABA(A)受体簇共定位，在HEK293细胞中与重组的GABA(A)受体共表达。重要的是，一种模拟PRIP结构域与β亚基结合的肽破坏了这些蛋白在HEK293细胞中的共定位，并有效地抑制了BDNF介导的野生型神经元GABA(A)受体电流的衰减。综上所述，这些结果表明，PRIP通过介导GABAA受体的β亚基与蛋白磷酸酶之间的特异性联系，在BDNF依赖的GABAA受体调节中发挥重要作用。
Brain-derived neurotrophic factor (BDNF) modulates several distinct aspects of synaptic transmission, including GABAergic transmission. Exposure to BDNF alters properties of GABA(A) receptors and induces changes in the expression level at the cell surface. Although phospholipase C-related inactive protein-1 (PRIP-1) plays an important role in GABA(A) receptor trafficking and function, its role in BDNF-dependent modulation of these receptors, together with the role of PRIP-2, was investigated using neurons cultured from PRIP double knock-out mice. The BDNF-dependent inhibition of whole cell GABA-evoked currents observed in wild type neurons was not detected in neurons cultured from knock-out mice. Instead, a gradual increase in GABA-evoked currents in these neurons correlated with a gradual increase in phosphorylation of GABA(A) receptor beta 3 subunit in response to BDNF. To characterize the specific role(s) that PRIP plays as components of underlying molecular machinery, we examined the recruitment of protein phosphatase(s) to GABA(A) receptors. We demonstrate that PRIP associates with phosphatases as well as with beta subunits. PRIP was found to colocalize with GABA(A) receptor clusters in cultured neurons and with recombinant GABA(A) receptors when co-expressed in HEK293 cells. Importantly, a peptide mimicking a domain of PRIP involved in binding to beta subunits disrupted the co-localization of these proteins in HEK293 cells and potently inhibited the BDNF-mediated attenuation of GABA(A) receptor currents in wild type neurons. Together, the results suggest that PRIP plays an important role in BDNF-dependent regulation of GABAA receptors by mediating the specific association between beta subunits of these receptors with protein phosphatases.