Binding to its receptor activates G proteins and stimulates adenylate cyclase in pituitary cells (By similarity). Promotes neuron projection development through the RAPGEF2/Rap1/B-Raf/ERK pathway. In chromaffin cells, induces long-lasting increase of intracellular calcium concentrations and neuroendocrine secretion (PubMed:18198219). Involved in the control of glucose homeostasis, induces insulin secretion by pancreatic beta cells (By similarity). Interacts with ADCYAP1R1 (via N-terminal extracellular domain). Belongs to the glucagon family.