Gene structure of the human metabotropic glutamate receptor 5 and functional analysis of its multiple promoters in neuroblastoma and astroglioma cells
Gene structure of the human metabotropic glutamate receptor 5 and functional analysis of its multiple promoters in neuroblastoma and astroglioma cells
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DOI：
10.1074/jbc.m212380200
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发表时间：
2003-08-29
影响因子：
4.8
通讯作者：
Ferraguti, F
中科院分区：
文献类型：
--
作者：
Corti, C;Clarkson, RWE;Ferraguti, F
代谢型谷氨酸受体5（mGluR 5）具有主要限于神经细胞的离散组织表达。mGluR 5的表达是发育调节的，并经历了与神经病理学疾病相关的巨大变化。我们报道了mGluR 5基因的全基因组结构，该基因由11个外显子组成，全长约563 kbp。位于三个不同外显子（IA，IB和II）上的三个多转录起始位点簇进行选择性剪接，已被确定。分离这些外显子的5 '侧翼区域，并使用荧光素酶报告基因测定，显示SKN-MC神经母细胞瘤和U178-MG星形胶质瘤细胞中具有活性启动子元件。启动子IA的特征在于由CpG岛;启动子IB含有TATA盒，和启动子II具有三个活性的Oct-1结合位点。在SKN-MC中观察到优先的荧光素酶活性，伴随着对几个响应元件（包括CREB、Oct-1、C/EBP和Brn-2）的差异DNA结合活性。暴露于生长因子产生增强的表达的启动子IB和II在星形胶质瘤细胞和激活NF-κ B。这些结果表明，选择性5 '-剪接和使用多个启动子可能有助于组织和上下文特异性表达的mGluR 5基因的调节机制。
The metabotropic glutamate receptor 5 (mGluR5) has a discrete tissue expression mainly limited to neural cells. Expression of mGluR5 is developmentally regulated and undergoes dramatic changes in association with neuropathological disorders. We report the complete genomic structure of the mGluR5 gene, which is composed of 11 exons and encompasses similar to563 kbp. Three clusters of multiple transcription initiation sites located on three distinct exons (IA, IB, and II), which undergo alternative splicing, have been identified. The 5'-flanking regions of these exons were isolated and, using a luciferase reporter gene assay, shown to possess active promoter elements in SKN-MC neuroblastoma and U178-MG astroglioma cells. Promoter IA was characterized by a CpG island; promoter IB contained a TATA box, and promoter II possessed three active Oct-1-binding sites. Preferential luciferase activity was observed in SKN-MC concomitant with differential DNA binding activity to several responsive elements, including CREB, Oct-1, C/EBP, and Brn-2. Exposure to growth factors produced enhanced expression of promoters IB and II in astroglioma cells and activation of NF-kappaB. These results suggest that alternative 5'-splicing and usage of multiple promoters may contribute regulatory mechanisms for tissue- and context-specific expression of the mGluR5 gene.