High-level expression of the 32.5-kilodalton calelectrin in ductal epithelia as revealed by immunocytochemistry

• Published in: Differentiation (London) Vol. 33; no. 2; pp. 175 - 183
• Main Authors: Silva, Fred G., Sherrill, Karen, Spurgeon, Sandra, Südhof, Thomas C., Stone, Dennis K.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Elsevier B.V 01.01.1986; Blackwell Publishing Ltd; Blackwell
• Subjects: Animals; Annexins; Biological and medical sciences; calcium-binding protein; Calcium-Binding Proteins - analysis; Calcium-Binding Proteins - biosynthesis; calelectrin; Epithelial Cells; Epithelium - metabolism; Fundamental and applied biological sciences. Psychology; Immune Sera; Immunoenzyme Techniques; Male; Molecular Weight; Nerve Tissue Proteins - analysis; Rats; Tissue Distribution; Vertebrates: skin, associated glands, phaneres, light organs, various exocrine glands (salt gland, uropygial gland...), adipose tissue, connective tissue; Binding protein; Vertebrata; Mammalia; Calcium; Rat; Immunocytochemistry; Ultrastructure; Rodentia; Skin; Epithelium; Inorganic element
• ISSN: 0301-4681; 1432-0436
• DOI: 10.1111/j.1432-0436.1986.tb00423.x

Calelectrins are a family of antigenically related Ca 2+-binding proteins that have only recently been described. They have the important property of binding to membranes only in the presence of Ca 2+. We systematically studied the tissue localization of one calelectrin, the 32.5-kilodalton species, in rats using immunocytochemistry. We found that high levels were exclusively present in the epithelial cells of bile and pancreatic ducts, renal collecting ducts, bronchial epithelia, and brain ependyma. In all of these organs, the other cells were not immunoreactive. In addition, strong immunoreactivity was found in the intercalated disks of myocardial cells, and mild immunoreactivity was observed in several endocrine tissues. In contrast, the cellular distribution of the 67-kilodalton calelectrin was more diffuse, involving most parenchymal cells in addition to the already-mentioned cells. Due to the presence of high levels of 32.5-kilodalton calelectrin in some cell types, this protein may be used as a histochemical marker for differentiated ductal epithelial cells, some specialized epithelia, myocardial cells, and Paneth cells.