Miralles C P, Li M, Mehta A K, Khan Z U, De Blas A L
Department of Physiology and Neurobiology, University of Connecticut, Storrs, Connecticut 06269, USA.
J Comp Neurol. 1999 Nov 1;413(4):535-48.
A novel anti-beta(3) subunit-specific GABA(A) receptor (GABA(A)R) antibody has been prepared by immunizing a rabbit with a bacterial fusion protein of the large intracellular loop of the beta(3) subunit. The antiserum immunoprecipitated the solubilized GABA(A) receptor. The anti-beta(3) antibody was affinity purified on immobilized beta(3) large intracellular loop peptide. In immunoblots, the purified antibody reacted with a 57 KDa peptide. Immunocytochemistry with the affinity-purified antibody has revealed the localization of the beta(3) subunit in the rat brain. A comparative study with the immunocytochemical distribution of the beta(2) subunit has also been performed. There are areas of the brain and cell types where the distribution of beta(2) and beta(3) overlap (i.e., cerebral cortex, cerebellum,and most layers of the olfactory bulb). There are also clear differences in the expression of beta(3) and beta(2) in other brain areas and cell types. Thus, high beta(3) but low or no beta(2) expression was observed in the corpus striatum and in granule cells of the olfactory bulb. In the hippocampus the expression of beta(3) was considerably higher than that of beta(2), but some hippocampal interneurons showed high expression of beta(2). High beta(2) but little or no expression of beta(3) was observed in thalamic nuclei, substantia nigra, globus pallidus, inferior colliculus and the short axon cells of the olfactory bulb.
通过用β(3)亚基的大细胞内环的细菌融合蛋白免疫兔子，制备了一种新型的抗β(3)亚基特异性γ-氨基丁酸A受体（GABA(A)R）抗体。抗血清免疫沉淀了可溶解的GABA(A)受体。抗β(3)抗体在固定化的β(3)大细胞内环肽上进行亲和纯化。在免疫印迹中，纯化的抗体与一条57 kDa的肽发生反应。用亲和纯化的抗体进行免疫细胞化学研究揭示了β(3)亚基在大鼠脑中的定位。还进行了与β(2)亚基免疫细胞化学分布的比较研究。脑的某些区域和细胞类型中，β(2)和β(3)的分布存在重叠（即大脑皮层、小脑和嗅球的大多数层）。在其他脑区和细胞类型中，β(3)和β(2)的表达也存在明显差异。因此，在纹状体和嗅球的颗粒细胞中观察到β(3)表达高而β(2)表达低或无表达。在海马体中，β(3)的表达明显高于β(2)，但一些海马体中间神经元显示出β(2)的高表达。在丘脑核、黑质、苍白球、下丘以及嗅球的短轴突细胞中观察到β(2)表达高而β(3)表达很少或无表达。
