Welcome Sun

Sun Jung has joined the Huber Lab as a research assistant.

Design, Synthesis and Characterization of Covalent KDM5 Inhibitors.

Our latest research published in Angewandte Chemie

https://onlinelibrary.wiley.com/doi/full/10.1002/anie.201810179

Histone lysine demethylases (KDMs) are involved in the dynamic regulation of gene expression and they play a critical role in several biological processes. Achieving selectivity over the different KDMs has been a major challenge for KDM inhibitor development. Here we report potent and selective KDM5 covalent inhibitors designed to target cysteine residues only present in the KDM5 sub‐family. The covalent binding to the targeted proteins was confirmed by MS and time‐dependent inhibition. Additional competition assays show that compounds were non 2‐OG competitive. Target engagement and ChIP‐seq analysis showed that the compounds inhibited the KDM5 members in cells at nano‐ to micromolar levels and induce a global increase of the H3K4me3 mark at transcriptional start sites.

Chemical Instability and Promiscuity of Arylmethylidenepyrazolinone-Based MDMX Inhibitors.

Our latest research published in ACS Chemical Biology

https://pubs.acs.org/doi/10.1021/acschembio.8b00665

Targeting the protein–protein interaction between p53 and MDM2/MDMX (MDM4) represents an attractive anticancer strategy for the treatment of p53-competent tumors. Several selective and potent MDM2 inhibitors have been developed and entered the clinic; however, the repertoire of MDMX antagonists is still limited. The arylmethylidenepyrazolinone SJ-172550 has been reported as a selective MDMX antagonist; yet, uncertainties about its mechanism of action have raised doubts about its use as a chemical probe. Here, we show that, in addition to its unclear mode of action, SJ-172550 is unstable in aqueous buffers, giving rise to side products of unknown biological activity. Using an SJ-172550-derived affinity probe, we observed promiscuous binding to cellular proteins whereas cellular thermal shift assays did not reveal a stabilizing effect on MDMX. Overall, our results raise further questions about the interpretation of data using SJ-172550 and related compounds to investigate cellular phenotypes.