(= polymorphic epithelial mucin, PEM; epithelial membrane antigen, EMA)Heavily glycosylated membrane glycoprotein. Encoded by the MUC- 1 gene; has a molecular weight of around 300 kD, more than half of which is O -linked glycan. There is a 69 residue cytoplasmic domain and the extracellular domain may extend hundreds of nanometres beyond the plasma membrane; the increased expression in carcinoma cells may reduce the adhesion and mask antigenic properties of the cells. Similar functions are ascribed to ASGP, epiglycanin and leukosialin.
Dictionary of molecular biology. 2004.