Analysis of the human GDNF gene reveals an inducible promoter, three exons, a triplet repeat within the 3'-UTR and alternative splice products.
Glial cell line-derived neurotrophic factor (GDNF), a distant member of the TGF-beta superfamily, is a survival factor for various neurons, making it a potential therapeutic agent for neurodegenerative disorders. Here we present the genomic structure and characterization of the promoter of the human GDNF (hGDNF) gene. It contains three exons coding for a cDNA of 4.6 kb including large 5'- and 3'-untranslated regions (UTRs). The 3'-UTR contains a polymorphic AGG repeat that appears not to be expanded in patients suffering from different neurodegenerative disorders. RT-PCR results in at least three different hGDNF transcripts including one that lacks exon 2. Transient expression experiments reveal that exon 2 is essential for proper cellular processing to yield a secreted form of hGDNF, whereas expression of exon 3 alone is sufficient to code for a mature form of hGDNF retained within the cell. Our data show that the hGDNF gene is driven by a TATA-containing promoter preceding exon 1. A second promoter element has been mapped to a region 5' of exon 2. Both promoters are in close proximity to CpG islands covering exons 1 and 2. Using luciferase as a reporter gene, the TATA-containing hGDNF promoter facilitates a 20- to 40-fold increase in transcription when compared with a corresponding promoterless construct, whereas the second promoter confers only weak activity. Furthermore, fibroblast growth factor 2, tetradecanoyl 12-phorbol acetate, an inflammatory agent, and cAMP increase promoter activity, suggesting that GDNF transcriptional regulation is a target of exogenous signals.
Grimm
L
L
Department of Medical Genetics, University of Munich, Goethestrasse 29, 80336 Munich, Germany.
Holinski-Feder
E
E
Teodoridis
J
J
Scheffer
B
B
Schindelhauer
D
D
Meitinger
T
T
Ueffing
M
M
D017398:Alternative Splicing / Q000235:genetics*; D000595:Amino Acid Sequence; D000818:Animals; D017101:Bacteriophage P1 / Q000235:genetics; D001483:Base Sequence; D002273:Carcinogens / Q000494:pharmacology; D002460:Cell Line; D000242:Cyclic AMP / Q000494:pharmacology; D004247:DNA / Q000737:chemistry / Q000235:genetics; D018076:DNA, Complementary / Q000235:genetics; D004274:DNA, Recombinant; D016208:Databases, Factual; D005057:Eukaryotic Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D005091:Exons / Q000235:genetics*; D016222:Fibroblast Growth Factor 2 / Q000494:pharmacology; D015870:Gene Expression; D005786:Gene Expression Regulation / Q000187:drug effects; D015723:Gene Library; D005796:Genes / Q000235:genetics*; D005822:Genetic Vectors; D051100:Glial Cell Line-Derived Neurotrophic Factor; D006801:Humans; D007438:Introns / Q000235:genetics; D051379:Mice; D008969:Molecular Sequence Data; D009414:Nerve Growth Factors; D009419:Nerve Tissue Proteins / Q000235:genetics*; D019636:Neurodegenerative Diseases / Q000235:genetics; D011110:Polymorphism, Genetic; D011401:Promoter Regions, Genetic / Q000187:drug effects / Q000235:genetics / Q000502:physiology; D011993:Recombinant Fusion Proteins / Q000235:genetics; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D012689:Sequence Homology, Nucleic Acid; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014158:Transcription, Genetic / Q000235:genetics; D018911:Trinucleotide Repeats / Q000235:genetics*; D014407:Tumor Cells, Cultured
D002273:Carcinogens; D018076:DNA, Complementary; D004274:DNA, Recombinant; C495039:GDNF protein, human; C495040:Gdnf protein, mouse; D051100:Glial Cell Line-Derived Neurotrophic Factor; D009414:Nerve Growth Factors; D009419:Nerve Tissue Proteins; D011993:Recombinant Fusion Proteins; D016222:Fibroblast Growth Factor 2; D004247:DNA; D000242:Cyclic AMP; D013755:Tetradecanoylphorbol Acetate