LLY-507, a Cell-active, Potent, and Selective Inhibitor of Protein-lysine Methyltransferase SMYD2.

Hannah Nguyen, Abdellah Allali-Hassani, Stephen Antonysamy, Shawn Chang, Lisa Hong Chen, Carmen Curtis, Spencer Emtage, Li Fan, Tarun Gheyi, Fengling Li, Shichong Liu, Joseph R Martin, David Mendel, Jonathan B Olsen, Laura Pelletier, Tatiana Shatseva, Song Wu, Feiyu Fred Zhang, Cheryl H Arrowsmith, Peter J Brown, Robert M Campbell, Benjamin A Garcia, Dalia Barsyte-Lovejoy, Mary Mader, Masoud Vedadi

文献索引：J. Biol. Chem. 290 , 13641-53, (2015)

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摘要

SMYD2 is a lysine methyltransferase that catalyzes the monomethylation of several protein substrates including p53. SMYD2 is overexpressed in a significant percentage of esophageal squamous primary carcinomas, and that overexpression correlates with poor patient survival. However, the mechanism(s) by which SMYD2 promotes oncogenesis is not understood. A small molecule probe for SMYD2 would allow for the pharmacological dissection of this biology. In this report, we disclose LLY-507, a cell-active, potent small molecule inhibitor of SMYD2. LLY-507 is >100-fold selective for SMYD2 over a broad range of methyltransferase and non-methyltransferase targets. A 1.63-Å resolution crystal structure of SMYD2 in complex with LLY-507 shows the inhibitor binding in the substrate peptide binding pocket. LLY-507 is active in cells as measured by reduction of SMYD2-induced monomethylation of p53 Lys(370) at submicromolar concentrations. We used LLY-507 to further test other potential roles of SMYD2. Mass spectrometry-based proteomics showed that cellular global histone methylation levels were not significantly affected by SMYD2 inhibition with LLY-507, and subcellular fractionation studies indicate that SMYD2 is primarily cytoplasmic, suggesting that SMYD2 targets a very small subset of histones at specific chromatin loci and/or non-histone substrates. Breast and liver cancers were identified through in silico data mining as tumor types that display amplification and/or overexpression of SMYD2. LLY-507 inhibited the proliferation of several esophageal, liver, and breast cancer cell lines in a dose-dependent manner. These findings suggest that LLY-507 serves as a valuable chemical probe to aid in the dissection of SMYD2 function in cancer and other biological processes. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.