Secretogranin III (SCG3)

Secretogranin III is a member of the chromogranin/secretogranin family of neuroendocrine secretory proteins. Granins may serve as precursors for biologically active peptides. Some granins have been shown to function as helper proteins in sorting and proteolytic processing of prohormones; however, the function of this protein is unknown.

The deduced 468-amino acid protein, which has a calculated molecular mass of 53 kD, contains an N-terminal signal peptide, a secretogranin motif, 3 potential N-glycosylation sites, and a putative tyrosine sulfation site. SCG3 shares 87%, 87%, and 56% overall identity with the mouse, rat, and Xenopus orthologs, respectively. SCG3 localized to the perinuclear endoplasmic reticulum in transfected COS-7 cells.