Enables glucagon receptor binding activity and hormone activity. Involved in adenylate cyclase-modulating G protein-coupled receptor signaling pathway; negative regulation of appetite; and response to L-arginine. Located in extracellular space. Human ortholog(s) of this gene implicated in Alzheimer's disease and prediabetes syndrome. Orthologous to human GCG (glucagon). [provided by Alliance of Genome Resources, Apr 2022]