Andrade R P, Kötter P, Entian K-D, Casal M
Centro de Biologia, Departamento de Biologia, Universidade do Minho, Campus de Gualtar, 4710-057 Braga, Portugal.
Biochem Biophys Res Commun. 2005 Jun 24;332(1):254-62. doi: 10.1016/j.bbrc.2005.04.119.
The Saccharomyces cerevisiae JEN1 gene encoding the lactate transporter undergoes strong catabolic repression at both transcriptional and post-transcriptional levels. JEN1 mRNA decay is greatly accelerated upon the addition of a pulse of glucose, fructose or mannose to induced cell cultures. Mapping of the 5'UTRs and 3'UTRs of JEN1 transcripts revealed multiple transcription start-sites located at position -51, +391 or +972, depending on the cell culture conditions. The presence of the JEN1(+391) transcript correlated with rapid glucose-triggered mRNA degradation of the JEN1(-51) transcript, whereas when the small transcript started at position +972, the JEN1(-51) mRNA turnover rate was unaffected. Overexpressed JEN1(+391) transcript accelerated JEN1(-51) mRNA decay in all conditions tested but was not translated. We propose that the JEN1(+391) transcript may have a "sensor-like" function, regulating glucose-triggered degradation of JEN1(-51) protein-coding mRNA.
编码乳酸转运蛋白的酿酒酵母JEN1基因在转录和转录后水平均受到强烈的分解代谢阻遏。向诱导的细胞培养物中添加葡萄糖、果糖或甘露糖脉冲后，JEN1 mRNA的降解会大大加速。对JEN1转录本的5'UTR和3'UTR进行定位发现，根据细胞培养条件，多个转录起始位点位于-51、+391或+972位置。JEN1(+391)转录本的存在与葡萄糖触发的JEN1(-51)转录本mRNA快速降解相关，而当小转录本起始于+972位置时，JEN1(-51) mRNA的周转率不受影响。在所有测试条件下，过表达的JEN1(+391)转录本都会加速JEN1(-51) mRNA的降解，但不会被翻译。我们提出，JEN1(+391)转录本可能具有“传感器样”功能，调节葡萄糖触发的JEN1(-51)蛋白质编码mRNA的降解。
