De-Nterm-ining GLP1R signaling bias.

Biased agonism has emerged as a promising strategy for improving incretin therapeutics, yet the structural determinants of signaling bias remain incompletely understood. Building on their recent parathyroid hormone 1 receptor-β-arrestin structure, Zhao and colleagues identify extracellular loop 3 as a conformational switch controlling glucagon-like peptide-1 receptor transducer selectivity, enabling rational design of biased agonists.