Involved in the processing of hormone and other protein precursors at sites comprised of pairs of basic amino acid residues. Responsible for the release of glucagon from proglucagon in pancreatic A cells (By similarity). Release of protein hormones and neuropeptides from their precursors, generally by hydrolysis of -Lys-Arg-|- bonds. Localized in the secretion granules. Belongs to the peptidase S8 family. Furin subfamily.