Polycyclic Compounds Commons^™

The Guanine Nucleotide Exchange Factor Ric-8a Regulates The Sensitivity Of Constitutively Active Gαq To The Inhibitor Ym-254890, Morgan Dwyer, Jiansong Luo, Tyson Todd, Kendall Blumer, Gregory Tall, Philip Wedegaertner

Department of Biochemistry and Molecular Biology Faculty Papers

Heterotrimeric G proteins are stimulated under normal circumstances by G protein-coupled receptors to promote downstream intracellular signaling. Mutations can occur in αq at glutamine 209 (Q209) that cause constitutive, G protein-coupled receptor independent signaling due to disruption of GTPase activity. Specifically, Q209L/P mutations are oncogenic drivers of uveal melanoma. YM-254890 (YM) has been shown to selectively inhibit both WT and constitutively active (CA) αqQ209L/P by preventing the release of GDP and exchange for GTP, thereby halting downstream signaling. Because αqQL/P are thought to be primarily GTP-bound and GTPase deficient, the current mechanistic understanding of YM inhibition needs further investigation to …