Ito H, Hamabata T, Hori S H
Department of Zoology, Faculty of Science, Hokkaido University, Sapporo, Japan.
Mol Gen Genet. 1993 Dec;241(5-6):637-46. doi: 10.1007/BF00279906.
Tandem insertions of defective P elements (1.15 kb KP and 0.6 kb core P) accelerate the transcription rate of the glucose-6-phosphate dehydrogenase (G6PD) gene in Drosophila melanogaster. In this report, we have analyzed the activation mechanism of the G6PD promoter by in vitro transcription and gel retardation assays. Results showed that one cis-acting region in the core P and two such regions in the KP are associated with activation of the G6PD promoter, and that putative transcriptional regulatory protein(s) which specifically bind to each of the cis-acting regions are present in nuclear extracts of Canton S embryos. On the other hand, the P elements do not activate the normal actin 5C promoter, but activate the promoter when the 20 bp sequence around the G6PD transcription start site is placed in front of the promoter. It appears that the GC-rich region in this 20 bp sequence is required for the activation.
缺陷型P元件（1.15 kb的KP和0.6 kb的核心P）的串联插入加速了黑腹果蝇中葡萄糖-6-磷酸脱氢酶（G6PD）基因的转录速率。在本报告中，我们通过体外转录和凝胶阻滞分析来分析G6PD启动子的激活机制。结果表明，核心P中的一个顺式作用区域和KP中的两个此类区域与G6PD启动子的激活相关，并且在Canton S胚胎的核提取物中存在与每个顺式作用区域特异性结合的假定转录调节蛋白。另一方面，P元件不激活正常的肌动蛋白5C启动子，但当G6PD转录起始位点周围的20 bp序列置于该启动子之前时会激活该启动子。看来该20 bp序列中的富含GC区域是激活所必需的。
