Powers T, Dilova I, Chen C Y, Wedaman K
Section of Molecular and Cellular Biology, Center for Genetics and Development, Division of Biological Sciences, University of California Davis, Davis, CA 95616, USA.
Curr Top Microbiol Immunol. 2004;279:39-51. doi: 10.1007/978-3-642-18930-2_3.
Understanding how cell growth is regulated in response to environmental signals remains a challenging biological problem. Recent studies indicate the TOR (target of rapamycin) kinase acts within an intracellular regulatory network used by eukaryotic cells to regulate their growth according to nutrient availability. This network affects all aspects of gene expression, including transcription, translation, and protein stability, making TOR an excellent candidate as a global regulator of cellular activity. Here we review our recent studies of two specific transcriptional outputs controlled by TOR in the budding yeast, S. cerevisiae: (1) positive regulation of genes involved in ribosome biogenesis, and (2) negative regulation of genes required for de novo biosynthesis of glutamate and glutamine. These studies have raised the important issue as to how diverse nutritional cues can pass through a common signaling pathway and yet ultimately generate distinct transcriptional responses.
了解细胞如何响应环境信号来调节生长仍然是一个具有挑战性的生物学问题。最近的研究表明，雷帕霉素靶蛋白（TOR）激酶在真核细胞用于根据营养可用性调节其生长的细胞内调节网络中发挥作用。该网络影响基因表达的各个方面，包括转录、翻译和蛋白质稳定性，使TOR成为细胞活动全局调节因子的极佳候选者。在这里，我们回顾了我们最近对出芽酵母酿酒酵母中由TOR控制的两种特定转录输出的研究：（1）对参与核糖体生物合成的基因的正调控，以及（2）对谷氨酸和谷氨酰胺从头生物合成所需基因的负调控。这些研究提出了一个重要问题，即不同的营养信号如何能够通过共同的信号通路，但最终产生不同的转录反应。
