Winter Daniel L, Hart-Smith Gene, Wilkins Marc R
Systems Biology Initiative, School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, New South Wales 2052, Australia.
Systems Biology Initiative, School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, New South Wales 2052, Australia.
J Mol Biol. 2018 Jan 5;430(1):102-118. doi: 10.1016/j.jmb.2017.11.009. Epub 2017 Nov 26.
Protein methylation is one of the major post-translational modifications (PTMs) in the cell. In Saccharomyces cerevisiae, over 20 protein methyltransferases (MTases) and their respective substrates have been identified. However, the way in which these MTases are modified and potentially subject to regulation remains poorly understood. Here, we investigated six overexpressed S. cerevisiae protein MTases (Rkm1, Rkm4, Efm4, Efm7, Set5 and Hmt1) to identify PTMs of potential functional relevance. We identified 48 PTM sites across the six MTases, including phosphorylation, acetylation and methylation. Forty-two sites are novel. We contextualized the PTM sites in structural models of the MTases and revealed that many fell in catalytic pockets or enzyme-substrate interfaces. These may regulate MTase activity. Finally, we compared PTMs on Hmt1 with those on its human homologs PRMT1, PRMT3, CARM1, PRMT6 and PRMT8. This revealed that several PTMs are conserved from yeast to human, whereas others are only found in Hmt1. The mass spectrometry proteomics data have been deposited to the ProteomeXchange Consortium via the PRIDE partner repository with the dataset identifier PXD006767.
蛋白质甲基化是细胞中主要的翻译后修饰（PTM）之一。在酿酒酵母中，已鉴定出超过20种蛋白质甲基转移酶（MTase）及其各自的底物。然而，这些MTase的修饰方式以及潜在的调控机制仍知之甚少。在这里，我们研究了六种过表达的酿酒酵母蛋白质MTase（Rkm1、Rkm4、Efm4、Efm7、Set5和Hmt1），以确定具有潜在功能相关性的PTM。我们在这六种MTase中鉴定出48个PTM位点，包括磷酸化、乙酰化和甲基化。其中42个位点是新发现的。我们将这些PTM位点置于MTase的结构模型中，发现许多位点位于催化口袋或酶-底物界面。这些可能会调节MTase的活性。最后，我们比较了Hmt1及其人类同源物PRMT1、PRMT3、CARM1、PRMT6和PRMT8上的PTM。结果表明，几种PTM从酵母到人类都是保守的，而其他一些PTM仅在Hmt1中发现。质谱蛋白质组学数据已通过PRIDE合作伙伴库存入蛋白质组交换联盟，数据集标识符为PXD006767。
