Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, NY 11794-5215, USA.
FEMS Yeast Res. 2010 Nov;10(7):793-801. doi: 10.1111/j.1567-1364.2010.00680.x. Epub 2010 Sep 24.
Yeast Gis1 protein functions as a transcription factor after nutrient limitation and oxidative stress. In this report, we show that Gis1 also regulates the induction of several genes involved in spore wall synthesis during sporulation. Gis1 contains a JmjC domain near its N-terminus. In many proteins, JmjC domains provide histone demethylase activity. Whether the JmjC domain of Gis1 contributes to its transcriptional activation is still unknown. Here, we show that gis1 point mutations that abolish Fe (II) and α-ketoglutarate binding, known cofactors in other JmjC proteins, are still able to induce transcription normally during glucose starvation and sporulation. Even the deletion of the entire JmjC domain does not affect transcriptional activation by Gis1. Moreover, the JmjC domain is not required for the toxicity associated with Gis1 overexpression. The data demonstrate that the JmjC domain is dispensable for transcriptional activation by Gis1 during nutrient stress and sporulation.
酵母 Gis1 蛋白在营养限制和氧化应激后作为转录因子发挥作用。在本报告中,我们表明 Gis1 还调节孢子形成过程中涉及孢子壁合成的几个基因的诱导。Gis1 在其 N 端附近含有一个 JmjC 结构域。在许多蛋白质中,JmjC 结构域提供组蛋白去甲基化酶活性。Gis1 的 JmjC 结构域是否有助于其转录激活仍不清楚。在这里,我们表明,尽管 gis1 点突变会破坏 Fe(II)和α-酮戊二酸的结合,这是其他 JmjC 蛋白中的已知辅因子,但在葡萄糖饥饿和孢子形成过程中,这些突变仍能正常诱导转录。即使删除整个 JmjC 结构域也不会影响 Gis1 的转录激活。此外,JmjC 结构域对于 Gis1 过表达相关的毒性不是必需的。这些数据表明,在营养胁迫和孢子形成过程中,JmjC 结构域对于 Gis1 的转录激活是可有可无的。