title: An intronic promoter controls the expression of truncated human gamma-glutamyltransferase mRNAs.
abstract: We have identified and characterized a genomic DNA fragment containing the coding sequences corresponding to the human gamma-glutamyltransferase type 1 mRNA. The coding part of the gene spans over 16 kb and comprises 12 exons and 11 introns exhibiting a similar organization as for the mouse and rat GGT genes. The exons 1-7 encode the heavy subunit whereas exons 8-12 which encode the carboxy-terminal part of the heavy subunit (exon 8) and the light subunit are clustered in a 1.6-kb BglII fragment. Exons 7 and 8 are separated by a 3.9-kb intron containing in its 3' part the sequences corresponding to the 5'-UTRs of the truncated GGT mRNAs described for human lung. Sequence analysis upstream this transcribed region exhibited putative promoter sequences and after transient transfection significant promoter activities were measured in V79 lung fibroblasts and KYN-2 hepatoma cells but not in A2780 ovarian cells. This specificity disappeared when only 550 bp upstream the transcription start site were used as promoter. These results argue for a promoter of truncated GGT mRNAs in intron 7, specifically regulated in human tissues.
authors.affiliation: Centre du Médicament, Faculté de Pharmacie UHP Nancy 1, France.
authors.forename: H
authors.initials: H
authors.lastname: Leh
authors.forename: N
authors.initials: N
authors.lastname: Chikhi
authors.forename: K
authors.initials: K
authors.lastname: Ichino
authors.forename: G
authors.initials: G
authors.lastname: Guellaën
authors.forename: M
authors.initials: M
authors.lastname: Wellman
authors.forename: G
authors.initials: G
authors.lastname: Siest
authors.forename: A
authors.initials: A
authors.lastname: Visvikis
mesh_terms: D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D006224:Cricetinae; D015971:Gene Expression Regulation, Enzymologic; D006801:Humans; D051379:Mice; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic / Q000235:genetics*; D012333:RNA, Messenger / Q000096:biosynthesis* / Q000235:genetics*; D051381:Rats; D005723:gamma-Glutamyltransferase / Q000096:biosynthesis* / Q000235:genetics*
chemical_list: D012333:RNA, Messenger; D005723:gamma-Glutamyltransferase