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Other publication, 2007

Biology of serglycin proteoglycan: role in secretory granule biogenesis

Pejler, Gunnar


All proteoglycans (PGs) consist of a protein ”core” to which unbranched, negatively charges glycosaminoglycan (GAG) chains are attached. Among the various PGs, serglycin holds a unique position in being primarily located intracellular in secretory granule, whereas most other PGs are either present on the cell surface or located within the extracellular matrix [1]. Serglycin was actually the first PG for which the cDNA was cloned and it was initially identified in a mastocytoma. It has subsequently been shown that serglycin is highly expressed also by normal mast cells (MCs), of various species and of different MC subclasses. In addition, serglycin expression has been identified in variety of other hematopoietic cell lineages, such as macrophages, platelets, neutrophils and cytotoxic T-lymphocytes (CTLs)[1] and, moreover, serglycin has been identified in non-hematopoietic cells such as endothelial cells, ES cells and pancreatic acinar cells. Considering that serglycin PG was found to be located in secretory granule of MCs it was early suggested that its function was to promote the storage of the various inflammatory substances that are located in the MC granule. This notion was further supported by that many of the MC granule constituents, e.g. histamine and several proteases, are basically charged, with the possibility being that these mediators engage in electrostatic interactions with the strongly anionic serglycin PG. Indeed, when the serglycin gene was genetically targeted, it was found that MCs from serglycin-/- mice failed to store many of the basically charged compounds that are normally found within the MC secretory granule [2]

Published in

Book title: Glycoscience 2003-2007
Publisher: Mizutani Foundation for Glycoscience