CLONING OF THE GAMMA-AMINOBUTYRIC-ACID (GABA) RHO-1 CDNA - A GABA RECEPTOR SUBUNIT HIGHLY EXPRESSED IN THE RETINA
CLONING OF THE GAMMA-AMINOBUTYRIC-ACID (GABA) RHO-1 CDNA - A GABA RECEPTOR SUBUNIT HIGHLY EXPRESSED IN THE RETINA
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DOI：
10.1073/pnas.88.7.2673
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发表时间：
1991-04-01
影响因子：
11.1
通讯作者：
KAZAZIAN, HH
中科院分区：
文献类型：
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作者：
CUTTING, GR;LU, L;KAZAZIAN, HH
A型γ-氨基丁酸（GABA（A））受体是配体门控氯离子通道的一个家族，其是神经系统中的主要抑制性神经递质受体。 分子克隆揭示了组成这种异源寡聚受体的亚基的多样性，但每个先前阐明的亚基在保守的结构元件中显示氨基酸相似性。 我们已经使用这些高度保守的区域，通过使用聚合酶链反应（PCR）来识别该家族的其他成员。 一个PCR产物用于从人视网膜cDNA文库中分离全长cDNA。 从该cDNA序列预测的成熟蛋白长458个氨基酸，与先前鉴定的GABA（A）亚基显示30 - 38%的氨基酸相似性。 该基因主要在视网膜中表达，但在脑、肺和胸腺中也检测到转录物。 注射非洲爪蟾卵母细胞与RNA转录在体外产生GABA-响应性氯电导和表达的cDNA在COS细胞中产生GABA-可置换蝇蕈醇结合。 这些特征与我们鉴定的GABA亚基GABA rho-1一致，其具有显著的视网膜表达，增加了该配体门控离子通道受体家族的多样性和组织特异性。
Type A gamma-aminobutyric acid (GABA(A)) receptors are a family of ligand-gated chloride channels that are the major inhibitory neurotransmitter receptors in the nervous system. Molecular cloning has revealed diversity in the subunits that compose this heterooligomeric receptor, but each previously elucidated subunit displays amino acid similarity in conserved structural elements. We have used these highly conserved regions to identify additional members of this family by using the polymerase chain reaction (PCR). One PCR product was used to isolate a full-length cDNA from a human retina cDNA library. The mature protein predicted from this cDNA sequence is 458 amino acids long and displays between 30 and 38% amino acid similarity to the previously identified GABA(A) subunits. This gene is expressed primarily in the retina but transcripts are also detected in the brain, lung, and thymus. Injection of Xenopus oocytes with RNA transcribed in vitro produces a GABA-responsive chloride conductance and expression of the cDNA in COS cells yields GABA-displaceable muscimol binding. These features are consistent with our identification of a GABA subunit, GABA rho-1, with prominent retinal expression that increases the diversity and tissue specificity of this ligand-gated ion-channel receptor family.