Profile substrates and inhibitors of protein lysine methyltransferase

描述（由申请人提供）：蛋白质甲基转移酶通过多种翻译后甲基化协调表观遗传途径。该反应通过蛋白质赖氨酸甲基转移酶（PKMT）通过将SAM（S-腺苷-L-甲硫氨酸）的甲基转移到底物的特定赖氨酸来进行。这个过程中的错误与许多癌症有关。越来越多的证据表明，表观遗传多样性需要PKMT甲基化组蛋白和非组蛋白。然而，很少有工具可以明确地描述指定PKMT的非组蛋白靶点，特别是在增殖癌细胞的背景下。此外，很少有PKMT抑制剂可用于破坏PKMT功能。这种情况严重阻碍了我们开发以PKMT为新靶点的癌症治疗策略的能力。我们的长期目标是阐明和操纵PKMT的生物学功能，用于癌症的诊断和治疗。该提案的目的是开发新技术，并将其应用于鉴定癌症相关PKMT的蛋白质靶点和小分子抑制剂。了解PKMT的靶点将是充分理解PKMT表观遗传功能的关键一步。更重要的是，PKMT的抑制剂可以检查其癌症治疗效果。为了分析PKMT的靶点，我们设想可以将酶工程化以利用SAM类似物辅因子，从而用不同的化学基团标记其靶点。然后，不同的修改将被各自的报告者识别。与此同时，将实施一种新型的高通量筛选方法来鉴定PKMT的抑制剂。我们的目标剖析和走廊识别方法的影响进一步加强了他们的一般适用性，以其他PKMT。

DESCRIPTION (provided by applicant): Protein methyltransferases orchestrate epigenetic pathways through diverse posttranslational methylation. The reaction is carried out by protein lysine methyltransferases (PKMTs) through transferring the methyl group of SAM (S-adenosyl-L- methionine) to specific lysine(s) of substrates. The errors in the process have been implicated in many cancers. Accumulated evidence indicated that epigenetic diversity requires PKMTs to methylate histones and nonhistone proteins. However, few tools are available to unambiguously profile the nonhistone targets of designated PKMTs, particularly in context of proliferating cancer cells. In addition, few PKMT inhibitors are available to disrupt PKMT functions. Such situations significantly hinder our capability to develop cancer-therapeutic strategies with the PKMTs as novel targets. Our long-term goal is to elucidate and manipulate the biological functions of PKMT for cancer diagnosis and treatment. The objective of this proposal is to develop novel technologies and apply them to identify protein targets and small-molecule inhibitors of a cancer-relevant PKMT. Knowing the targets of the PKMT will be a key step toward fully understanding the epigenetic functions of the PKMT. More importantly, the inhibitors of the PKMT can be examined for their cancer-therapeutic effects. To profile the targets of the PKMT, we envision that the enzyme can be engineered to utilize SAM analogue cofactors and thus label its targets with distinct chemical groups. The distinct modifications will then be recognized by respective reporters. Meanwhile, a novel high-throughput screening approach will be implemented to identify the inhibitors of the PKMT. The impact of our target-profiling and inhibitor-identifying methods is further strengthened by their general applicability to other PKMTs.