The Platform Identifies Drug-Like Probes that Regulate Endogenous Protein Levels within Physiological Contexts.

Traditional phenotypic drug discovery platforms have suffered from poor scalability and a lack of mechanistic understanding of newly discovered phenotypic probes. To address this, we created Endo- (EGS), a high-throughput enabled screening platform that identifies bioactive small molecules capable of regulating endogenous protein expression encoded by any preselected target gene within a biologically appropriate context. As a proof-of-concept, successfully identified drug candidates that up-regulate endogenous expression of neuronal a gene that causes a neurodevelopmental disorder when haploinsufficient. For example, SR-1815, a previously unknown and undescribed kinase inhibitor, alleviated major cellular consequences of loss-of-function by restoring normal SynGAP protein levels and dampening neuronal hyperactivity within haploinsufficient neurons. Moreover, we demonstrate that assays accelerate preclinical development of identified drug candidates and facilitate mode-of-action deconvolution studies. Thus, identifies first-in-class bioactive small molecule probes that promote biological discovery and precision therapeutic development.