Celenza J L, Carlson M
Mol Cell Biol. 1984 Jan;4(1):54-60. doi: 10.1128/mcb.4.1.54-60.1984.
The SNF1 gene of Saccharomyces cerevisiae is essential for normal regulation of gene expression by glucose repression. A functional SNF1 gene product is required to derepress many glucose-repressible genes in response to conditions of low external glucose. In the case of the SUC2 structural gene for invertase, SNF1 acts at the RNA level. We have reported the isolation of a cloned gene that complements the snf1 defect in S. cerevisiae and that is homologous to DNA at the SNF1 locus (J. L. Celenza and M. Carlson, Mol. Cell. Biol. 4:49-53, 1984). In this work we identified a 2.4-kilobase polyadenylate-containing RNA encoded by the SNF1 gene and showed that its level is neither regulated by glucose repression nor dependent on a functional SNF1 product. The position of the SNF1 RNA relative to the cloned DNA was mapped, and the direction of transcription was determined. The cloned DNA was used to disrupt the SNF1 gene at its chromosomal locus. Gene disruption resulted in A Snf1- phenotype, thereby proving that the cloned gene is the SNF1 gene and showing that the phenotype of a true null mutation is indistinguishable from that of previously isolated snf1 mutations.
酿酒酵母的SNF1基因对于通过葡萄糖阻遏正常调控基因表达至关重要。需要有功能的SNF1基因产物来响应低外部葡萄糖条件，解除对许多葡萄糖可阻遏基因的阻遏。就转化酶的SUC2结构基因而言，SNF1在RNA水平起作用。我们已报道分离出一个克隆基因，它能弥补酿酒酵母中的snf1缺陷，并且与SNF1位点的DNA同源（J. L. 塞伦扎和M. 卡尔森，《分子细胞生物学》4:49 - 53，1984年）。在这项工作中，我们鉴定出由SNF1基因编码的一种含2.4千碱基聚腺苷酸的RNA，并表明其水平既不受葡萄糖阻遏调控，也不依赖于有功能的SNF1产物。绘制了SNF1 RNA相对于克隆DNA的位置，并确定了转录方向。用克隆DNA在其染色体位点破坏SNF1基因。基因破坏导致了一种Snf1 - 表型，从而证明克隆基因就是SNF1基因，并表明真正的无效突变的表型与先前分离的snf1突变的表型无法区分。
