Biopolymers and cell. 1998; 14 (5): 410 - 418

Structure and function of epithelial mucins

Irina Gout

Mucins are the structural, components of the epithelial mucose that protects the respiratory, gastrointestinal and reproductive tracts from the hostile environments, including microorganisms, toxins and abrasives. Mucins constitute a group of high molecular weight <> 200 kDa), polydisperse and highly glycosytated proteins which are present on the surface of most epithelial tissues. Our understanding of the structure and function of mucins lias advanced significantly in the last decade. This progress was mainly associated with the isolation of the cDNA clones, encoding a family of epithelial mucins. To date, this family includes eight mucin genes (MUC1—MUC8) and more await to be discovered. Based on sequence analysis and studies of subcellular localisation, epithelial mucins could be divided into two classes: membrane-associated (MUC1) and secretory (MUC2-S). This review is focused on our current knowledge of the structure of products of mucin genes and their function in normal tissues and in disease. The regulation of the expression of mucin genes, posttranslational modifications and alterations in secretion and processing will also be discussed.