Analysis of the human GDNF gene reveals an inducible promoter, three exons, a triplet repeat within the 3′-UTR and alternative splice products
Analysis of the human GDNF gene reveals an inducible promoter, three exons, a triplet repeat within the 3′-UTR and alternative splice products
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DOI：
10.1093/hmg/7.12.1873
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发表时间：
1998-11-01
影响因子：
3.5
通讯作者：
Ueffing, M
中科院分区：
文献类型：
--
作者：
Grimm, L;Holinski-Feder, E;Ueffing, M
胶质细胞源性神经营养因子（GDNF）是TGF-β超家族的远亲成员，是多种神经元的存活因子，使其成为神经退行性疾病的潜在治疗剂。本文报道了人GDNF（hGDNF）基因启动子的基因组结构和特征。该基因由3个外显子组成，编码一个4.6kb的cDNA，包括5 '和3'非翻译区（UTR）。RT-PCR产生至少三种不同的hGDNF转录物，包括一种与外显子2结合的转录物。瞬时表达实验表明，外显子2对于产生分泌形式的hGDNF的适当细胞加工是必需的，而外显子3单独的表达足以编码保留在细胞内的成熟形式的hGDNF。我们的数据表明，hGDNF基因是由一个TATA-含有启动子前外显子1。第二个启动子元件已定位于外显子2的5'区。这两个启动子都非常接近覆盖外显子1和2的CpG岛。使用荧光素酶作为报告基因，与相应的无启动子构建体相比，含TATA的hGDNF启动子促进转录增加20至40倍，而第二个启动子仅赋予弱活性。此外，成纤维细胞生长因子2，十四酰基12-佛波醇乙酸酯，炎症剂，和cAMP增加启动子活性，表明GDNF转录调节是外源性信号的目标。
Glial cell line-derived neurotrophic factor (GDNF), a distant member of the TGF-P 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 tacks 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.