Reserpine-induced alterations in mucus production and calmodulin-binding proteins in a human epithelial cell line.
The characterization of a mucus-producing human cell line (HC-84) derived from a colon carcinoma and its response to in vitro reserpine treatment is reported. Mucous granules were demonstrated within these cells on the basis of electron microscopic examination and incorporation of [3H]glucosamine with subsequent autoradiographic analysis. Fluorographic analysis of total HC-84 cell protein after incubation with [3H]glucosamine indicated that the majority of tritium was incorporated into two proteins with molecular weights of 115 and 120 kD. When total HC-84 protein was subjected to immuno-blot analysis utilizing rabbit antibody against human intestinal mucus, only these two proteins (115K and 120K) reacted positively, indicating a direct correlation between [3H]glucosamine incorporation and mucus production. Immunofluorescence localization of mucus within HC-84 cells utilizing this same antibody resulted in a punctate pattern of fluorescence within the cytoplasm. Treatment of HC-84 cells with 30 microM reserpine for 7 days resulted in a three-fold increase in mucus production compared with controls. There was also a concomitant loss of a 30K calmodulin-binding protein in cells treated with reserpine. These cells represent a useful system for studying the effect of reserpine on the processes of mucus synthesis and secretion.
D002135:Calcium-Binding Proteins / Q000378:metabolism*; D002148:Calmodulin-Binding Proteins; D002460:Cell Line; D003110:Colonic Neoplasms; D003593:Cytoplasm / Q000032:analysis; D003594:Cytoplasmic Granules / Q000648:ultrastructure; D005944:Glucosamine / Q000378:metabolism; D006023:Glycoproteins / Q000032:analysis / Q000096:biosynthesis*; D006801:Humans; D009093:Mucus / Q000032:analysis / Q000378:metabolism*; D010749:Phosphoprotein Phosphatases / Q000378:metabolism*; D012110:Reserpine / Q000494:pharmacology*
D002135:Calcium-Binding Proteins; D002148:Calmodulin-Binding Proteins; D006023:Glycoproteins; D012110:Reserpine; D010749:Phosphoprotein Phosphatases; D005944:Glucosamine