Farmer A A, Johnsen J I, Loftus T M, Smith K P, Stanbridge E J
Department of Microbiology and Molecular Genetics, University of California, Irvine, College of Medicine, CA 92715, USA.
Nucleic Acids Res. 1996 Jun 1;24(11):2158-65. doi: 10.1093/nar/24.11.2158.
This report describes the isolation, sequencing and preliminary characterization of the first 1 kb of the 5'-regulatory region of the human QM gene. This region and the 5' -half of the transcribed region of the QM gene are enriched for C and G nucleotides with no bias against CpG dinucleotides--indicative of a CpG island. Several consensus GC boxes are present within the sequence. Most are clustered at the distal end, with one site present in the proximal 200 bp of the promoter. Electrophoretic mobility shift experiments and luciferase assays done in insect cells transfected with an Sp1 expression construct suggest that most of these sites can bind Sp1 or a closely related factor. In addition, the promoter is shown to be responsive to cAMP via a response element (CRE) in the proximal promoter. Studies with 5'-end and internal deletion mutants suggest that elements in the distal promoter exert their positive effect through interactions with a proximal element(s). Candidate proximal elements include the proximal GC box and a 43 bp region between a KpnI site (at -182) and a Smal site (at -139).
本报告描述了人类QM基因5'调控区首个1 kb片段的分离、测序及初步特征分析。该区域以及QM基因转录区的5'半区富含C和G核苷酸，对CpG二核苷酸无偏向性，这表明存在一个CpG岛。序列中存在几个共有GC盒。大多数聚集在远端，在启动子近端200 bp内有一个位点。在转染了Sp1表达构建体的昆虫细胞中进行的电泳迁移率变动实验和荧光素酶测定表明，这些位点中的大多数可结合Sp1或密切相关的因子。此外，通过近端启动子中的一个反应元件（CRE），该启动子显示出对cAMP有反应。对5'端和内部缺失突变体的研究表明，远端启动子中的元件通过与近端元件相互作用发挥其正向作用。候选近端元件包括近端GC盒以及KpnI位点（位于-182）和Smal位点（位于-139）之间的一个43 bp区域。
