Garcia J V, Bich-Thuy L T, Stafford J, Queen C
Nature. 1986;322(6077):383-5. doi: 10.1038/322383a0.
Enhancers are DNA sequences that stimulate transcription from eukaryotic promoters. This stimulatory effect can be exerted over large distances and from a position either 5' or 3' of a promoter. Enhancers have been found in the genomes of many viruses, and in some cellular genes such as those encoding immunoglobulin heavy chain and kappa light chain. An important feature of both viral and cellular enhancers is the ability of each enhancer to stimulate transcription from many promoters other than the one with which it is found associated. However, the question of whether cellular enhancers stimulate their 'own' promoter more efficiently than other promoters has apparently not been investigated. We show here that the kappa light-chain enhancer stimulates a kappa promoter about 20-fold more than it stimulates either the simian virus 40 (SV40) early promoter or a metallothionein (MT) promoter, two promoters that are very sensitive to other enhancers. Similarly, the heavy-chain enhancer stimulates a heavy-chain promoter much more than it stimulates the SV40 and MT promoters. This synergism between immunoglobulin enhancers and promoters might be due to the action of a protein that binds specifically to each of the regulatory elements.
增强子是刺激真核生物启动子转录的DNA序列。这种刺激作用可以在远距离发挥，并且可以从启动子的5'或3'位置发挥作用。增强子已在许多病毒的基因组中以及一些细胞基因中被发现，例如那些编码免疫球蛋白重链和κ轻链的基因。病毒和细胞增强子的一个重要特征是每个增强子能够刺激与其相关联的启动子以外的许多其他启动子的转录。然而，细胞增强子是否比其他启动子更有效地刺激其“自身”启动子的问题显然尚未得到研究。我们在此表明，κ轻链增强子刺激κ启动子的效率比刺激猿猴病毒40（SV40）早期启动子或金属硫蛋白（MT）启动子高约20倍，这两种启动子对其他增强子非常敏感。同样，重链增强子刺激重链启动子的程度远大于刺激SV40和MT启动子。免疫球蛋白增强子与启动子之间的这种协同作用可能是由于一种与每个调节元件特异性结合的蛋白质的作用。
