Yamagami Setsu, Morioka Daisuke, Fukuda Ryouichi, Ohta Akinori
Department of Biotechnology, The University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, Tokyo, 113-8657, Japan.
J Biol Chem. 2004 May 21;279(21):22183-9. doi: 10.1074/jbc.M313313200. Epub 2004 Mar 24.
When the alkane-assimilating yeast Yarrowia lipolytica is cultivated on n-alkanes, it changes cellular metabolism for adaptation by inducing cytochrome p450 and other genes. From a comparative analysis of promoters of alkane-inducible genes, we identified a cis-acting element, ARE1 (alkane responsive element 1), which provides transcription induction in response to n-alkanes. In a genetic selection for mutants that were defective in ARE1-mediated transcription induction in the presence of n-alkanes, we found that the YAS1 (yeast alkane signaling) gene is essential for alkane response. The YAS1 gene encodes a basic helix-loop-helix (bHLH) family protein. Loss of Yas1p causes defects in n-alkane-dependent transcription induction of the p450 gene and growth on n-alkanes. Yas1p localizes to nuclei and binds to promoters containing ARE1. Yas1p also binds to its own promoter, and the expression of YAS1 is induced by n-alkanes. These features suggest that Yas1p is a novel transcription factor mediating alkane signaling and that it provides an autoregulatory loop.
当烷烃同化酵母解脂耶氏酵母在正构烷烃上培养时，它会通过诱导细胞色素P450和其他基因来改变细胞代谢以实现适应。通过对烷烃诱导基因启动子的比较分析，我们鉴定出一个顺式作用元件ARE1（烷烃反应元件1），它能响应正构烷烃提供转录诱导。在对在正构烷烃存在下ARE1介导的转录诱导有缺陷的突变体进行的遗传筛选中，我们发现YAS1（酵母烷烃信号传导）基因对烷烃反应至关重要。YAS1基因编码一种碱性螺旋-环-螺旋（bHLH）家族蛋白。Yas1p的缺失会导致p450基因的正构烷烃依赖性转录诱导缺陷以及在正构烷烃上的生长缺陷。Yas1p定位于细胞核并与含有ARE1的启动子结合。Yas1p还与其自身的启动子结合，并且YAS1的表达由正构烷烃诱导。这些特征表明Yas1p是一种介导烷烃信号传导的新型转录因子，并且它提供了一个自调节环。
