MUC1 monoclonal antibody

Mucins represent a family of glycoproteins characterized by repeat domains and dense O-glycosylation. MUC1 (or mucin 1) is aberrantly overexpressed in most human carcinomas. Increased expression of MUC1 in carcinomas reduces cell-cell and cell-ECM interactions. MUC1 is cleaved proteolytically, and the large ectodomain can remain associated with the small 25 kDa carboxy-terminal domain that contains a transmembrane segment and a 72-residue cytoplasmic tail. MUC1 interacts with ErbB family receptors and potentiates ERK1/2 activation. MUC1 also interacts with β-catenin, which is regulated by GSK-3β, PKCγ, and Src through phosphorylation at Ser44, Thr41, and Tyr46 of the MUC1 cytoplasmic tail. Overexpression of MUC1 potentiates transformation and attenuates stress-induced apoptosis through the Akt or p53 pathways.