Maniak M, Nellen W
Max-Planck-Institut für Biochemie, Abt. Zellbiologie, Martinsried, FRG.
Nucleic Acids Res. 1990 Sep 25;18(18):5375-80. doi: 10.1093/nar/18.18.5375.
We have previously described the elements of two overlapping promoters regulating differential expression of the Dictyostelium P8A7 gene. One promoter was constitutively active but stimulated during development (S-promoter), while the other (L-promoter) was found to be induced by a variety of stimuli. This effect was mediated by the induction (i-) element. By a series of antisense transformation experiments we here provide evidence that this element is the target of a feedback control circuit. In wild type cells, feedback regulation activates the L-promoter in unfavourable environmental situations when transcription from the S-promoter is insufficient to generate adequate amounts of protein. A model for the function of the feedback loop under natural and experimental conditions is presented.
我们之前已经描述了调控盘基网柄菌P8A7基因差异表达的两个重叠启动子的元件。一个启动子组成性活跃，但在发育过程中受到刺激（S启动子），而另一个（L启动子）被发现受多种刺激诱导。这种效应由诱导（i-）元件介导。通过一系列反义转化实验，我们在此提供证据表明该元件是一个反馈控制回路的靶点。在野生型细胞中，当S启动子的转录不足以产生足够量的蛋白质时，反馈调节在不利的环境条件下激活L启动子。本文提出了自然和实验条件下反馈环功能的模型。
