1. Discovery of a dual Ras and ARF6 inhibitor from a GPCR endocytosis screen
- Author
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Jenna Giubilaro, Doris Schuetz, Yoon Namkung, Etienne Khoury, Monica Marquez, Shirley Campbell, Alexandre Beautrait, Sylvain Armando, Olivier Radresa, Jean Duchaine, Nathalie Lamarche-Vane, Audrey Claing, Michel Bouvier, Anne Marinier, and Stéphane Laporte
- Abstract
Internalization and intracellular trafficking of hormone receptors, like receptor tyrosine kinases (RTKs) and G protein-coupled receptors (GPCRs), play pivotal roles in cell responsiveness homeostasis. Dysregulation in receptor trafficking can lead to aberrant signaling and cell behavior, prevalent in cancer. Here, using an endosomal BRET-based assay in a high-throughput screen with the prototypical GPCR angiotensin II type 1 receptor (AT1R), we sought to identify inhibitors of receptor trafficking from a library of ~115,000 small molecules. We identified a novel dual Ras and ARF6 inhibitor that blocks agonist-mediated internalization of AT1R and other GPCRs, which we named Rasarfin. Rasarfin also potently inhibited agonist-induced ERK1/2 signaling by GPCRs, and MAPK and Akt signaling by EGFR, as well as prevented cancer cell proliferation. In silico modeling and in vitro studies revealed a unique binding modality of Rasarfin within the SOS-binding domain of Ras. Our findings unveil a new class of dual small G protein inhibitors for receptor trafficking and signaling, useful for the inhibition of oncogenic cellular responses.
- Published
- 2020
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