Chromogranin A

Chromogranin A
Available structures PDB Ortholog search: PDBe, RCSB List of PDB id codes 1LV4
Identifiers
Symbols	CHGA ; CGA
External IDs	OMIM: 118910 MGI: 88394 HomoloGene: 976 GeneCards: CHGA Gene
Gene ontology Molecular function • calcium ion binding Cellular component • extracellular region • secretory granule • transport vesicle membrane • mast cell granule • perinuclear region of cytoplasm Biological process • mast cell chemotaxis • regulation of blood pressure • killing of cells of other organism • mast cell cytokine production • negative regulation of catecholamine secretion • mast cell degranulation • innate immune response • mast cell activation • defense response to Gram-negative bacterium • defense response to Gram-positive bacterium • defense response to fungus • positive regulation of dense core granule biogenesis Sources: Amigo / QuickGO
RNA expression pattern
More reference expression data
Orthologs
Species	Human	Mouse
Entrez	1113	12652
Ensembl	ENSG00000100604	ENSMUSG00000021194
UniProt	P10645	P26339
RefSeq (mRNA)	NM_001275	NM_007693
RefSeq (protein)	NP_001266	NP_031719
Location (UCSC)	Chr 14: 92.92 – 92.94 Mb	Chr 12: 102.55 – 102.57 Mb
PubMed search	[1]	[2]

Chromogranin A or parathyroid secretory protein 1 (gene name CHGA) is a member of the granin family of neuroendocrine secretory proteins, i.e., it is located in secretory vesicles of neurons and endocrine cells such as islet beta cell secretory granules in pancreas. In humans, chromogranin A protein is encoded by the CHGA gene.

Tissue distribution

Examples of cells producing chromogranin A (ChgA) 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.

Function

Chromogranin A is the precursor to several functional peptides including vasostatin-1, vasostatin-2, pancreastatin, catestatin and parastatin. These peptides negatively modulate the neuroendocrine function of the releasing cell (autocrine) or nearby cells (paracrine).

Chromogranin A induces and promotes the generation of secretory granules such as those containing insulin in pancreatic islet beta cells.

Clinical significance

Micrograph of a paraganglioma stained with chromogranin A immunostain.

Chromogranin A is elevated in pheochromocytomas. It has been identified as autoantigen in type 1 diabetes. A peptide fragment of ChgA located in the Vasostatin-1, namely ChgA29-42 has been identified as the antigenic epitope recognized by diabetogenic BDC2.5 T cells from type 1 diabetes prone NOD mice.

It is used as an indicator for pancreas and prostate cancer and in carcinoid syndrome. It might play a role in early neoplasic progression. Chromogranin A is cleaved by an endogenous prohormone convertase to produce several peptide fragments. See chromogranin A GeneRIFs for references. In immunohistochemistry it can be used to identify a range of neuroendocrine tumours and is highly specific for both benign and malignant cells of this type.

External links

• chromogranin A antibody stains via Google Image [3]