Targeted protein degradation reveals BET bromodomains as the cellular target of Hedgehog pathway inhibitor-1

作者：Meropi Bagka, Hyeonyi Choi, Margaux Héritier, Hanna Schwaemmle, Quentin T. L. Pasquer, Simon M. G. Braun, Léonardo Scapozza, Yibo Wu, Sascha Hoogendoorn · 发表于：Nature Communications · 年份：2023 · DOI：10.1038/s41467-023-39657-1 · 被引用次数：20 · 研究领域：Protein Degradation and Inhibitors、Hedgehog Signaling Pathway Studies、Chromatin Remodeling and Cancer

Target deconvolution of small molecule hits from phenotypic screens presents a major challenge. Many screens have been conducted to find inhibitors for the Hedgehog signaling pathway - a developmental pathway with many implications in health and disease - yielding many hits but only few identified cellular targets. We here present a strategy for target identification based on Proteolysis-Targeting Chimeras (PROTACs), combined with label-free quantitative proteomics. We develop a PROTAC based on Hedgehog Pathway Inhibitor-1 (HPI-1), a phenotypic screen hit with unknown cellular target. Using this Hedgehog Pathway PROTAC (HPP) we identify and validate BET bromodomains as the cellular targets of HPI-1. Furthermore, we find that HPP-9 is a long-acting Hedgehog pathway inhibitor through prolonged BET bromodomain degradation. Collectively, we provide a powerful PROTAC-based approach for target deconvolution, that answers the longstanding question of the cellular target of HPI-1 and yields a PROTAC that acts on the Hedgehog pathway.