Concordet J P, Maire P, Kahn A, Daegelen D
ICGM, INSERM U129, Paris, France.
Nucleic Acids Res. 1991 Aug 11;19(15):4173-80. doi: 10.1093/nar/19.15.4173.
The human aldolase A gene is transcribed from three different promoters, which are all clustered within a 1.6 kbp DNA domain. Two of these, PN and PH, are ubiquitous and seem to be co-regulated in most tissues while the third one, PM, is specific to adult skeletal muscle. We investigated the sequences involved in the ubiquitous activity of the PN and PH promoters of the human aldolase A gene. Deletion analysis, performed by transient expression assays of chloramphenicol acetyltransferase reporter genes in human HepG2 hepatoma cells, indicated that PH activity results from the interaction of an upstream activating region with two distinct core promoters. The upstream activating region was able to stimulate transcription from the HSV tk promoter as efficiently as the SV40 enhancer in all cell types tested. It appears, therefore, to be a strong ubiquitous enhancer. DNAsel footprinting revealed protections covering sequences scattered along the enhancer, including Sp1 and AP1 motifs. Importantly, we found that this enhancer was also necessary to activity of the other ubiquitous promoter of the aldolase A gene, PN. These studies demonstrate that expression of the human aldolase A gene is mediated by a complex interplay of enhancer and promoter elements.
人类醛缩酶A基因由三个不同的启动子转录，这些启动子都聚集在一个1.6kbp的DNA结构域内。其中两个启动子，PN和PH，在所有组织中都普遍存在，并且在大多数组织中似乎受到共同调控，而第三个启动子PM则特异性地存在于成人骨骼肌中。我们研究了人类醛缩酶A基因PN和PH启动子普遍活性所涉及的序列。通过在人HepG2肝癌细胞中对氯霉素乙酰转移酶报告基因进行瞬时表达分析来进行缺失分析，结果表明PH活性是由一个上游激活区域与两个不同的核心启动子相互作用产生的。在所有测试的细胞类型中，上游激活区域刺激单纯疱疹病毒胸苷激酶启动子转录的效率与SV40增强子一样高。因此，它似乎是一个强大的普遍存在的增强子。DNA酶足迹分析揭示了沿着增强子分散的序列保护区域，包括Sp1和AP1基序。重要的是，我们发现这个增强子对于醛缩酶A基因的另一个普遍存在的启动子PN的活性也是必需的。这些研究表明，人类醛缩酶A基因的表达是由增强子和启动子元件之间复杂的相互作用介导的。
