Merck, SML2784-5MG, CMPD101 hydrochloride

Biochem/physiol Actions
Active site-targeting, potent and subtype-selective G protein-coupled receptor kinase GRK2/3 inhibitor with no inhibitory potency against GRK1/5.
CMPD101 is an active site-targeting, potent and subtype-selective G protein-coupled receptor kinase GRK2 & GRK3 inhibitor (human GRK2/3 IC₅₀ = 54/32 nM with 3 μM ATP and tubulin dimer as substrate; bovine GRK2 IC₅₀ = 290 nM with 0.5 mM ATP and bROS as substrate; no GRK1/5 inhibition at 125 μM). CMPD101 selectively inhibits GPR39 agonist-induced β-arrestin recruitment (by 94% at 10 μM against 30 μM GPR39-C3/50 μM ZnCl2), but not cAMP pathway desensitization in cultures and prevents β-arrestin2-biased D2R ligand UNC9994(1 μg/side bilateral local injection) from blocking NMDAR antagonist PCP (6 mg/kg i.p.)-induced locomotion (60%/12% blockage without/with 0.5 μg CMPD101 co-injection) in mice in vivo.