Secretagogin (SCGN)

SCGN contains 6 tandem repeats of the EF-hand Ca(2+)-binding domain, with a loop at all 6 putative Ca(2+)-binding sites, and shares significant similarity with calbindin and calretinin. Much lower expression of only the smaller transcript was detected in adrenal medulla, stomach, thyroid, colon, and small intestine.Immunohistochemical analysis showed SCGN expression restricted to the islet of Langerhans in pancreas, in C cells near thyroid follicles, and at sites typically occupied by neuroendocrine cells in all other tissues examined. Cell fractionation and confocal imaging of transfected rat insulinoma cells detected Scgn predominantly in the cytosolic fraction, with much less Scgn in nuclei. SCGN was expressed in a reticular pattern in transfected COS cells.