MOLECULAR CHARACTERIZATION OF GLUTAMATE RECEPTOR EXPRESSION IN BRAIN

脑中谷氨酸受体表达的分子特征

• 批准号: 3842310
• 负责人: A BUONANNO
• 金额: --
• 依托单位: EUNICE KENNEDY SHRIVER NATIONAL INSTITUTE OF CHILD HEALTH & HUMAN DEVELOPMENT
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/3842310
• 关键词: NMDA receptors; RNA splicing; Xenopus oocyte; cerebellum; complementary DNA; denervation; developmental neurobiology; dorsal root; excitatory aminoacid; ganglions; gene expression; genetic library; glutamate receptor; kainate; molecular cloning; molecular genetics; northern blottings; nucleic acid probes; oligonucleotides; protein sequence; receptor binding; receptor expression; transfection; voltage /patch clamp

Glutamate receptors (GluRs) have been implicated in simple forms of learning and memory and are the site of action of several psychoactive drugs. GluRs have been broadly classified in the non-NMDA and NMDA subtypes. Molecular cloning of non-NMDA GluR cDNAs has revealed a large family of related receptor subunits that can be classified into distinct groups by their sequence similarity and binding preferences for either AMPA (GluRs 1-4) or kainate (GluRs 5-7 and KAR 1,2). Alternative splicing and RNA editing add further complexity to the different receptor isoforms that can be generated from a single GluR gene, resulting in the assembly of receptors that exhibit marked differences in ion-selectivity and desensitization properties. Previously, we reported on the cloning of a novel GluR 4 transcript that results from the differential RNA processing of sequences coding for an alternative C-terminus; we designated this isoform GluR-4c. We observed on Northern blots containing cerebellar RNA, that GluR-4 oligonucleotide probes corresponding to the N-terminal extracellular domain of the receptor hybridized to bands of 6.2, 4.2, and 3.0 kb. However, probes derived from sequences corresponding to the middle or C-terminal end of the protein hybridized exclusively to the larger bands. We now have obtained CDNAS corresponding to the short 3.0 kb transcript; they have been called GluR-4s. DNA sequencing of these cDNAs revealed that the 3.0 kb mRNAs are derived from GluR-4 nascent transcripts by differential splicing, and that they code for a protein that is identical to GluR-4c for most of the N-terminal region, but diverge and terminate to yield a truncated polypeptide. In contrast to the other GluR-4 isoforms, which are expressed in neurons and glia, GluR-4s transcripts are predominantly expressed in cerebellar granule neurons. In collaboration with Dr. Mayer's laboratory, we have begun to identify the non-NMDA GluR isoforms expressed by dorsal root ganglia (DRG) and determine the molecular components underlying the heterogeneity of DRG responses to glutamate analogs. The effects of denervation on GluR expression have also been studied.

谷氨酸受体（GluR）与简单形式的 学习和记忆，是几种精神活性物质的作用部位。 毒品GluRs被广泛地分为非NMDA和NMDA受体。 亚型。非NMDA GluR cDNA的分子克隆已经揭示了大的 相关受体亚单位家族，可分为不同的 根据它们的序列相似性和结合偏好， AMPA（GluRs 1-4）或红藻氨酸盐（GluRs 5-7和KAR 1，2）。替代 剪接和RNA编辑进一步增加了不同的复杂性， 可以由单个GluR基因产生的受体同种型， 从而导致表现出显著差异的受体的组装 在离子选择性和脱敏性能。此前我们 报道了一种新的GluR 4转录本的克隆， 不同的RNA加工序列编码的替代 C-末端;我们将此同种型命名为GluR-4c。我们在北方观察到 含有小脑RNA的印迹，GluR-4寡核苷酸探针 对应于受体的N-末端胞外结构域 与6.2、4.2和3.0kb的条带杂交。然而，探测器 从对应于所述多肽的中间或C末端的序列， 蛋白质只与较大的条带杂交。我们现在已经获得了 CDNAS对应于短的3.0 kb转录本;它们已经被 叫做GluR-4这些cDNA的DNA测序表明，3.0 kb的cDNA序列与DNA序列完全一致。 mRNA通过差异表达从GluR-4新生转录物衍生。 它们编码的蛋白质与GluR-4c相同 对于大部分的N-末端区域，但分叉并终止以产生一个 截短的多肽。与其他GluR-4亚型相比， 在神经元和神经胶质细胞中表达，GluR-4s转录物主要是 表达于小脑颗粒神经元。与博士合作。 Mayer的实验室，我们已经开始鉴定非NMDA GluR亚型 背根神经节（DRG）表达，并决定分子 背根神经节对谷氨酸反应异质性的潜在成分 类似物去神经支配对GluR表达的影响也被研究。 研究了