Chromogranin A

Chromogranin A is the major protein co-stored and co-released with catecholamines from secretory vesicles in adrenal medulla and postganglionic sympathetic axons. It is required for formation of catecholamine secretory vesicles in chromaffin cells and its expression may be sufficient even to induce a regulated secretory system in non-secretory cells. It is also a pro-hormone that gives rise to biologically active peptides such as the dysglycemic peptide pancreastatin, the antimicrobial peptide chromacin, the vasodilator vasostatin, and catestatin that acts to inhibit catecholamine release.