γ-氨基丁酸B型受体亚基2 (GABA-B receptor 2) (GABA-B-R2) (GABA-BR2) (GABABR2) (Gb2) (G蛋白偶联受体51) (HG20)
γ-氨基丁酸B型受体亚基2 (GABA-B receptor 2) (GABA-B-R2) (GABA-BR2) (GABABR2) (Gb2) (G蛋白偶联受体51) (HG20)
O75899功能描述
GABA异二聚体G蛋白偶联受体的组分，由GABBR1和GABBR2形成 (PubMed:15617512, PubMed:18165688, PubMed:22660477, PubMed:24305054, PubMed:9872316, PubMed:9872744)。在异二聚体GABA受体中，似乎只有GABBR1结合激动剂，而GABBR2介导与G蛋白的偶联 (PubMed:18165688)。配体结合引起构象变化，通过鸟苷酸结合蛋白（G蛋白）触发信号传导，并调节下游效应子的活性，例如腺苷酸环化酶 (PubMed:10075644, PubMed:10773016, PubMed:24305054)。信号传导抑制腺苷酸环化酶，刺激磷脂酶A2，激活钾通道，失活电压依赖性钙通道并调节肌醇磷脂水解 (PubMed:10075644, PubMed:10773016, PubMed:10906333, PubMed:9872744)。在抑制性突触传递的微调中起关键作用 (PubMed:22660477, PubMed:9872744)。突触前GABA受体通过下调高压激活钙通道抑制神经递质释放，而突触后GABA受体通过激活显著的内向整流钾（Kir）电导降低神经元兴奋性，该电导是晚期抑制性突触后电位的基础 (PubMed:10075644, PubMed:22660477, PubMed:9872316, PubMed:9872744)。不仅与突触抑制有关，还与海马长时程增强、慢波睡眠、肌肉松弛和抗伤害感受有关 (Probable)。 {ECO:0000269|PubMed:10075644, ECO:0000269|PubMed:10328880, ECO:0000269|PubMed:15617512, ECO:0000269|PubMed:18165688, ECO:0000269|PubMed:22660477, ECO:0000269|PubMed:24305054, ECO:0000269|PubMed:9872316, ECO:0000269|PubMed:9872744, ECO:0000305}。
组织特异性
Highly expressed in brain, especially in cerebral cortex, thalamus, hippocampus, frontal, occipital and temporal lobe, occipital pole and cerebellum, followed by corpus callosum, caudate nucleus, spinal cord, amygdala and medulla (PubMed:10087195, PubMed:10328880, PubMed:10727622, PubMed:9872744). Weakly expressed in heart, testis and skeletal muscle (PubMed:10087195, PubMed:10727622).
亚细胞定位
Cell membrane
关键词