Rasarfin

Dual inhibitor of Ras and ARF6 discovered by screening a library of over 115,000 small molecules employing an endosomal BRET-based assay with the prototypical GPCR angiotensin II type 1 receptor (AT1R) seeking to identify inhibitors of receptor trafficking. IC50=7 and 0.7 µM for ARF and Ras respectively with no inhibition of Rac/Cdc42 and Rho up to 100 µM. It blocks agonist-mediated internalization of AT1R and other GPCRs. It also potently inhibits agonist-induced ERK1/2 signaling by GPCRs and MAPK and AKT signaling by EGFR (IC50=4-5 µM) and prevents cancer cell proliferation. Rasarfin’s direct action on Ras was also verified using purified H-Ras in an in vitro GEF exchange assay.1