title: Gene structure of the human metabotropic glutamate receptor 5 and functional analysis of its multiple promoters in neuroblastoma and astroglioma cells.
abstract: 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 approximately 563 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-kappa B. 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.
authors.affiliation: Cambridge Brain Bank Laboratory, Department of Pathology, University of Cambridge, Level 3 Laboratory Block Addenbrooke's Hospital, Hills Road, CB2 2QQ Cambridge, United Kingdom.
authors.forename: Corrado
authors.initials: C
authors.lastname: Corti
authors.forename: Richard W E
authors.initials: RW
authors.lastname: Clarkson
authors.forename: Luca
authors.initials: L
authors.lastname: Crepaldi
authors.forename: Cinzia F
authors.initials: CF
authors.lastname: Sala
authors.forename: John H
authors.initials: JH
authors.lastname: Xuereb
authors.forename: Francesco
authors.initials: F
authors.lastname: Ferraguti
mesh_terms: D020121:5' Untranslated Regions; D017398:Alternative Splicing; D000818:Animals; D001254:Astrocytoma / Q000378:metabolism*; D001483:Base Sequence; D001665:Binding Sites; D015152:Blotting, Northern; D001921:Brain / Q000378:metabolism; D016466:CHO Cells; D018899:CpG Islands; D006224:Cricetinae; D004247:DNA / Q000378:metabolism; D018076:DNA, Complementary / Q000378:metabolism; D019992:Databases as Topic; D005091:Exons; D005786:Gene Expression Regulation; D017930:Genes, Reporter; D006801:Humans; D008156:Luciferases / Q000378:metabolism; D051379:Mice; D008957:Models, Genetic; D008969:Molecular Sequence Data; D016328:NF-kappa B / Q000378:metabolism; D009447:Neuroblastoma / Q000378:metabolism*; D009841:Oligonucleotides / Q000737:chemistry; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D064529:Receptor, Metabotropic Glutamate 5; D018094:Receptors, Metabotropic Glutamate / Q000235:genetics* / Q000502:physiology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012260:Ribonucleases / Q000378:metabolism; D014158:Transcription, Genetic; D014162:Transfection; D014407:Tumor Cells, Cultured
chemical_list: D020121:5' Untranslated Regions; D018076:DNA, Complementary; C578935:GRM5 protein, human; C578936:Grm5 protein, mouse; C578937:Grm5 protein, rat; D016328:NF-kappa B; D009841:Oligonucleotides; D012333:RNA, Messenger; D064529:Receptor, Metabotropic Glutamate 5; D018094:Receptors, Metabotropic Glutamate; D004247:DNA; D008156:Luciferases; D012260:Ribonucleases