Also known as parathyroid secretory protein 1 is a member of the granin family of neuroendocrine secretory proteins.
It is located in secretory vesicles of neurons and endocrine cells such as islet beta cell secretory granules in pancreas.
It is encoded by the CHGA gene.
Cells producing chromogranin A are chromaffin cells of the adrenal medulla, paraganglia, enterochromaffin-like cells and beta cells of the pancreas.
It is present in islet beta cell secretory granules.
It is the precursor to several functional peptides including vasostatin-1, vasostatin-2, pancreastatin, catestatin and parastatin.
The above peptides negatively modulate the neuroendocrine function of the releasing cell or nearby cells.
Promotes the generation of secretory granules such as those containing insulin in pancreatic islet beta cells.
It is elevated in pheochromocytomas.
Used as an indicator for pancreas and prostate cancer and in carcinoid syndrome.
In immunohistochemistry it can be used to identify neuroendocrine tumors.
It is highly specific for both benign and malignant cells of the neuroendocrine type.