Polymorphic Epithelial Mucin, also known as PEM or MUC1, is a glycoprotein that is primarily expressed on the surface of various human epithelial cells. It belongs to the mucin family of proteins, which are characterized by their high content of carbohydrate structures, particularly O-linked glycans.
MUC1 is encoded by the MUC1 gene, and it consists of a large extracellular domain, a transmembrane domain, and a short cytoplasmic tail. The extracellular domain is highly glycosylated, resulting in a heavily glycosylated mucin-like structure. This glycosylation contributes to the polymorphic nature of the mucin, as the composition and structure of the carbohydrate side chains can vary among individuals and even within different tissues.
Polymorphic Epithelial Mucin plays crucial roles in various physiological and pathological processes. It has been found to participate in cell adhesion, protection against pathogens, immune response modulation, and cell signaling. Moreover, its aberrant expression and altered glycosylation patterns have been implicated in several diseases, including cancer.
Due to its involvement in disease processes and its presence on the surface of many epithelial cells, Polymorphic Epithelial Mucin has attracted considerable attention as a potential target for diagnostics, therapeutics, and vaccines. Ongoing research aims to further elucidate its functions, the implications of its polymorphic nature, and the development of targeted interventions.
