Chen C Y, Hitzeman R A
Nucleic Acids Res. 1987 Jan 26;15(2):643-60. doi: 10.1093/nar/15.2.643.
When the gene for yeast 3-phosphoglycerate kinase (PGK) is present on a high copy number plasmid in Saccharomyces cerevisiae, 30-40 percent of yeast protein is produced as PGK. However, when the structural part of this gene is replaced by as many as twenty different heterologous genes, production of gene products is greatly reduced--usually by more than 20 fold. This decrease in protein production is accompanied by large decreases in the steady-state levels of mRNA. However, in contrast to these coding sequences, replacement of the yeast PGK structural gene with a human PGK cDNA has little effect on the steady-state mRNA level in yeast. PGK is a two-domain enzyme and its 3-dimensional structure is highly conserved among species. These observations and others have led us to propose that the PGK protein itself might influence its own mRNA levels (Chen et al., Nucleic Acids Res. 12, pp. 8951-8969, 1984). In addition, data is presented here which suggest that the human PGK mRNA is less efficiently translated than the yeast PGK mRNA. Two different mechanisms of controlling gene expression are indicated. Both mechanisms appear to be independent of gene copy number.
当酵母3-磷酸甘油酸激酶（PGK）基因存在于酿酒酵母的高拷贝数质粒上时，30%-40%的酵母蛋白以PGK的形式产生。然而，当该基因的结构部分被多达20个不同的异源基因取代时，基因产物的产量会大幅降低——通常降低超过20倍。蛋白质产量的这种下降伴随着mRNA稳态水平的大幅下降。然而，与这些编码序列不同的是，用人PGK cDNA取代酵母PGK结构基因对酵母中的mRNA稳态水平几乎没有影响。PGK是一种双结构域酶，其三维结构在物种间高度保守。这些观察结果以及其他结果使我们提出，PGK蛋白本身可能会影响其自身的mRNA水平（Chen等人，《核酸研究》12卷，第8951 - 8969页，1984年）。此外，本文提供的数据表明，人PGK mRNA的翻译效率低于酵母PGK mRNA。表明了两种不同的基因表达调控机制。这两种机制似乎都与基因拷贝数无关。
