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Publication — IRIC

Discovery of a dual Ras and ARF6 inhibitor from a GPCR endocytosis screen.

Internalization and intracellular trafficking of G protein-coupled receptors (GPCRs) play pivotal roles in cell responsiveness. Dysregulation in receptor trafficking can lead to aberrant signaling and cell behavior. 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 receptor trafficking inhibitors from a library of ~115,000 small molecules. We identified a novel dual Ras and ARF6 inhibitor, which we named Rasarfin, that blocks agonist-mediated internalization of AT1R and other GPCRs. Rasarfin also potently inhibits agonist-induced ERK1/2 signaling by GPCRs, and MAPK and Akt signaling by EGFR, as well as prevents cancer cell proliferation. In silico modeling and in vitro studies reveal a unique binding modality of Rasarfin within the SOS-binding domain of Ras. Our findings unveil a class of dual small G protein inhibitors for receptor trafficking and signaling, useful for the inhibition of oncogenic cellular responses.

Publication date
August 3, 2021
Principal Investigators
Giubilaro J, Schuetz DA, Stepniewski TM, Namkung Y, Khoury E, Lara-Márquez M, Campbell S, Beautrait A, Armando S, Radresa O, Duchaine J, Lamarche-Vane N, Claing A, Selent J, Bouvier M, Marinier A, Laporte SA
PubMed reference
Nat Commun 2021;12(1):4688
PubMed ID
Department of Pharmacology and Therapeutics, McGill University, Montréal, QC, Canada.