Dhayalan Arunkumar, Kudithipudi Srikanth, Rathert Philipp, Jeltsch Albert
Biochemistry Laboratory, School of Engineering and Science, Jacobs University Bremen, Campus Ring 1, 28759 Bremen, Germany.
Chem Biol. 2011 Jan 28;18(1):111-20. doi: 10.1016/j.chembiol.2010.11.014.
We applied peptide array methylation to determine an optimized target sequence for the SET7/9 (KMT7) protein lysine methyltransferase. Based on this, we identified 91 new peptide substrates from human proteins, many of them better than known substrates. We confirmed methylation of corresponding protein domains in vitro and in vivo with a high success rate for strongly methylated peptides and showed methylation of nine nonhistone proteins (AKA6, CENPC1, MeCP2, MINT, PPARBP, ZDH8, Cullin1, IRF1, and [weakly] TTK) and of H2A and H2B, which more than doubles the number of known SET7/9 targets. SET7/9 is inhibited by phosphorylation of histone and nonhistone substrate proteins. One lysine in the MINT protein is dimethylated in vitro and in vivo demonstrating that the product pattern created by SET7/9 depends on the amino acid sequence context of the target site.
我们应用肽阵列甲基化来确定SET7/9（KMT7）蛋白赖氨酸甲基转移酶的优化靶序列。基于此，我们从人类蛋白质中鉴定出91种新的肽底物，其中许多优于已知底物。我们在体外和体内证实了相应蛋白质结构域的甲基化，对于强甲基化肽的成功率很高，并显示出9种非组蛋白（AKA6、CENPC1、MeCP2、MINT、PPARBP、ZDH8、Cullin1、IRF1和[弱]TTK）以及H2A和H2B的甲基化，这使已知的SET7/9靶标数量增加了一倍多。SET7/9受到组蛋白和非组蛋白底物蛋白磷酸化的抑制。MINT蛋白中的一个赖氨酸在体外和体内都发生了二甲基化，这表明SET7/9产生的产物模式取决于靶位点的氨基酸序列背景。
