MUC-1

Epithelial-Mesenchymal Transition (EMT) is the trans-differentiation of stationary epithelial cells into motile mesenchymal cells. During EMT, epithelial cells lose their junctions and apical-basal polarity, reorganize their cytoskeleton, undergo a change in the signaling cascade that defines cell shape and reprograms gene expression. Collectively, these changes increase the motility of individual cells and enables the development of an invasive phenotype.

Mucin 1 (Muc1) is a heavily glycosylated protein that coats mucosal epithelial cells of the lungs, intestines, and other organs. Muc1 is thought to protect cells by binding to pathogens and responding to infections. During trafficking to the plasma membrane Muc1 is proteolytically cleaved in the endoplasmic reticulum to form a stable heterodimeric complex of two fragments. The smaller C-terminal region contains the cytoplasmic tail and transmembrane domain and is non-covalently bound to the larger glycosylated extracellular domain.