Human MUC-4 Antibody

MUC-4 (Mucin-4), also called ASGP (Ascites Sialoglycoprotein) is a highly glycosylated type I transmembrane glycoprotein that may be up to 950 kDa in its full-length, fully glycosylated form. Human MUC-4 cDNA encodes 2169 amino acids (aa) with a 28 aa signal sequence and a cleavage site that creates a 1416 aa soluble, extracellular alpha chain and a 725 aa single-pass transmembrane beta chain. Between aa 1072-1317 within the alpha chain, human MUC-4 shares 69% aa sequence identity with mouse and rat MUC-4. At least 14 soluble or transmembrane splice variants of 1102-2117 aa have been described, 5 of which contain the full sequence used as an immunogen. MUC-4 can serve as a ligand for the oncogenic receptor ErbB2 and a modulator of its phosphorylation and signaling. MUC-4 is frequently aberrantly expressed in epithelial tumors and can promote tumor growth and metastasis.