Characterization of the Dnmt2 metyltransferase homolog pmt1 from Schizosaccharomyces pombe

粟酒裂殖酵母 Dnmt2 甲基转移酶同源 pmt1 的表征

• 批准号: 119069956
• 负责人: Professorin Dr. Ann Elizabeth Ehrenhofer-Murray
• 金额: --
• 依托单位: Arbeitsgruppe Molekulare Zellbiologie
• 依托单位国家: 德国
• 项目类别: Research Units
• 财政年份: 2009
• 资助国家: 德国
• 起止时间: 2008-12-31 至 2014-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/119069956?language=en
• 关键词: Characterization; Dnmt2; metyltransferase; homolog; pmt1

DNA methylation on cytosine residues is a modification used by many organisms to regulate gene expression. The fission yeast Schizosaccharomyces pombe carries a homolog of the Dnmt2 family of methyltransferases called Pmt1, but possesses no detectable DNA methylation. Our work has shown that Pmt1 has tRNA methylation activity, both in vitro and in vivo. Surprisingly, its in vivo activity is strongly regulated by nutritional conditions, and this regulation requires the serine/ threonine kinase Sck2 and has an impact on chronological aging in S. pombe.In this project, we will expand on this work and will further define the nutritional requirements and dynamics of Pmt1-dependent tRNA methylation, and we will seek to identify other conditions for Pmt1 induction. We will evaluate Sck2 as well as other kinase signaling pathways for their role in Pmt1 activation and will ask whether it occurs via a direct or indirect phosphorylation of Pmt1 or by interaction of Pmt1 with other proteins. Furthermore, we will place the effect of Pmt1 on aging in the context of known aging pathways. Based on the knowledge gained in the first grant period, we will search for genes that show a synthetic lethal interaction with pmt1Δ, which will give indications as to functional roles of Pmt1. Finally, we will reevaluate the role of Pmt1 on epigenetic gene silencing, taking into consideration the nutritional circumstances of Pmt1 activation.

胞嘧啶残基上的 DNA 甲基化是许多生物体用来调节基因表达的修饰。裂殖酵母粟酒裂殖酵母携带 Dnmt2 甲基转移酶家族的同源物（称为 Pmt1），但没有可检测到的 DNA 甲基化。我们的工作表明，Pmt1 在体外和体内均具有 tRNA 甲基化活性。令人惊讶的是，其体内活性受到营养条件的强烈调节，这种调节需要丝氨酸/苏氨酸激酶 Sck2，并对粟酒裂殖酵母的时间老化产生影响。在本项目中，我们将扩展这项工作，并进一步确定 Pmt1 依赖性 tRNA 甲基化的营养需求和动态，并且我们将寻求确定 Pmt1 诱导的其他条件。我们将评估 Sck2 以及其他激酶信号传导通路在 Pmt1 激活中的作用，并询问其是否通过 Pmt1 的直接或间接磷酸化或通过 Pmt1 与其他蛋白质的相互作用发生。此外，我们将把 Pmt1 对衰老的影响置于已知衰老途径的背景下。基于在第一个资助期获得的知识，我们将寻找与 pmt1Δ 表现出合成致死相互作用的基因，这将表明 Pmt1 的功能作用。最后，我们将重新评估 Pmt1 对表观遗传基因沉默的作用，同时考虑 Pmt1 激活的营养环境。