Antibodies to High Molecular Weight Polypeptides of Desmosomes: Specific Localization of a Class of Junctional Proteins in Cells and Tissues

• Published in: Differentiation (London) Vol. 20; no. 1; pp. 217 - 241
• Main Authors: FRANKE, WERNER W., SCHMID, ERIKA, GRUND, CHRISTINE, MÜLLER, HELGA, ENGELBRECHT, IRMTRAUD, MOLL, ROLAND, STADLER, JOACHIM, JARASCH, ERNST-DIETER
• Format: Journal Article
• Language: English
• Published: Oxford, UK Elsevier B.V 01.01.1981; Blackwell Publishing Ltd
• Subjects: animal physiology
• ISSN: 0301-4681; 1432-0436
• DOI: 10.1111/j.1432-0436.1981.tb01178.x

Desmosome-enriched fractions were isolated from bovine muzzle epidermis either as desmosome-tonofilament complexes using a procedure involving treatment at pH 9 or in the form of desmosomal residue fractions using a modification of the citric acid buffer (pH 2.3) method of Skerrow and Matoltsy [1]. Major polypeptides of high molecular weights (mol. wt.) were separated by gel electrophoresis, individual polypeptide bands were excised, and protein was eluted and used for immunization. Guinea pig antibodies raised against two prominent polypeptides of high mol. wt. (250,000 and 215,000) showed, on nitrocellulose paper blots of desmosome-tonofilament polypeptides separated by gel electrophoresis, extensive cross-reaction between a group or large polypeptides characteristic of desmosome-containing fractions, most notably polypeptides of 250 K, 215 K, 200 K, 175 K, and 164 K. These antibodies allowed, when used in immunofluorescence microscopy, the specific localization of desmosomal junctions (i) in sections through epithelia-containing tissues (e.g., epidermis, mucosae of tongue and esophagus, cornea, mammary gland, small intestine, liver, thymus, urothelium of bladder) and myocardium; (ii) on dissociated cells from these tissues; (iii) on various epithelial cells grown in culture; and (iv) in tumor-like proliferations of cultured epithelial cells injected into nude mice. Individual desmosomes could be visualized and resolved at the light microscopic level. No reaction was found in cells devoid of desmosomes and on other classes of intercellular junctions. Electron microscopic localization using immunoperoxidase techniques indicated that these proteins are located in, or close to, the desmosomal plaque structure. It is proposed to use such antibodies against desmosomal proteins as markers specific to this so far only morphologically defined class of junctions. Use of these markers will (i) improve identification and classification of intercellular junctions; (ii) facilitate determinations of the specific patterns of distributions of desmosomes and desmosomal protein in various cells and tissues; (iii) allow studies of formation and disintegration of desmosomes, and of the biosynthesis and possible recycling of their constituents; and (iv) provide tissue group-specific markers valuable in histology and diagnosis, especially for identification of epithelial and carcinoma cells.