Mazzoni Cristina, Serafini Agnese, Falcone Claudio
Pasteur Institute-Cenci Bolognetti Foundation, Department of Cell and Developmental Biology, University of Rome La Sapienza, 00185 Rome, Italy.
Genetics. 2005 Jul;170(3):1023-32. doi: 10.1534/genetics.105.041863. Epub 2005 May 6.
We have isolated the KlNOT4 gene of the yeast Kluyveromyces lactis, which encodes a component of the evolutionarily conserved CCR4-NOT complex. We show that inactivation of the gene leads to pleiotropic defects that were differentially suppressed by the NOT4 gene of S. cerevisiae, indicating that these genes have overlapping, but not identical, functions. K. lactis strains lacking Not4p are defective in fermentation and show reduced transcription of glucose transporter and glycolytic genes, which are phenotypes that are not found in the corresponding mutant of S. cerevisiae. We also show that Not4 proteins control the respiratory pathway in both yeasts, although with some differences. They activate transcription of KlACS2 and KlCYC1, but repress KlICL1, ScICL1, ScACS1, and ScCYC1. Altogether, our results indicate that Not4p is a pivotal factor involved in the regulation of carbon metabolism in yeast.
我们已经分离出乳酸克鲁维酵母的KlNOT4基因，该基因编码进化保守的CCR4-NOT复合物的一个组分。我们发现该基因的失活会导致多效性缺陷，酿酒酵母的NOT4基因可对这些缺陷进行差异性抑制，这表明这些基因具有重叠但并非完全相同的功能。缺乏Not4p的乳酸克鲁维酵母菌株在发酵方面存在缺陷，并且葡萄糖转运蛋白和糖酵解基因的转录减少，而这些表型在酿酒酵母的相应突变体中并未发现。我们还表明，Not4蛋白在两种酵母中均控制呼吸途径，不过存在一些差异。它们激活KlACS2和KlCYC1的转录，但抑制KlICL1、ScICL1、ScACS1和ScCYC1。总之，我们的结果表明Not4p是参与酵母碳代谢调控的关键因子。
