Serglycin

Serglycin, also known as hematopoietic proteoglycan core protein or secretory granule proteoglycan core protein, is a protein that in humans is encoded by the SRGN gene. It is primarily expressed in hematopoietic cells and endothelial cells, and is the only known intracellular proteoglycan.

Function
This gene encodes a protein best known as a hematopoietic cell granule proteoglycan. Proteoglycans stored in the secretory granules of many hematopoietic cells also contain a protease-resistant peptide core, which may be important for neutralizing hydrolytic enzymes. This encoded protein was found to be associated with the macromolecular complex of granzymes and perforin, and serves as a scaffold for the granzyme and perforin in granule-mediated apoptosis.