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Updated: Jun 27, 2026
Mucin Agarose Gel Electrophoresis: Western Blotting for High-molecular-weight Glycoproteins
Published on: June 14, 2016
Characterization of human mucin (MUC15) and identification of ovine and caprine orthologs
L T Pallesen1, L R L Pedersen, T E Petersen
1Department of Molecular Biology, University of Aarhus, 8000 Aarhus C, Denmark.
Abstract:
The glycoprotein MUC15 (mucin 15) was initially isolated from the bovine milk fat globule membrane. The present work demonstrates the existence of immunologically similar proteins ( approximately 130 kDa) in ovine, caprine, porcine, and buffalo milk samples. Purification and N-terminal amino acid sequencing confirmed the presence of ovine and caprine MUC15 orthologs in milk fat globule membranes. Expression of MUC15 in human milk was demonstrated by immunostaining ( approximately 150 kDa) as well as by mass spectrometry. Screening of a human multiple tissue expression array showed abundant MUC15 gene expression in placenta, salivary gland, thyroid gland, trachea, esophagus, kidney, testis, and the leukemia K-562 cell line. Furthermore, moderate expression was seen in the pancreas, adult and fetal lung, fetal kidney, lymph node, adult and fetal thymus, and parietal lobe. Structural motifs for interactions (epidermal growth factor receptor and Src homology 2 domains) are identified in the intracellular region. Implication of the mucin in signal transduction and the potential physiological function of MUC15 are discussed.
Insights
Mucin 15 (MUC15) proteins are found in milk from various mammals, including humans. This glycoprotein plays a role in signal transduction and has diverse tissue expression, suggesting important physiological functions.
Area of Science:
- Biochemistry
- Molecular Biology
- Cell Biology
Background:
- Mucin 15 (MUC15) was first identified in bovine milk fat globule membranes.
- The presence and characteristics of MUC15 in other mammalian milk sources were previously uncharacterized.
Purpose of the Study:
- To investigate the presence and characteristics of MUC15 in milk from various mammalian species.
- To determine the expression patterns of MUC15 in human tissues.
- To explore the potential physiological functions and signal transduction roles of MUC15.
Main Methods:
- Immunological assays to detect MUC15 in milk samples.
- Protein purification and N-terminal amino acid sequencing.
- Immunostaining and mass spectrometry for human milk expression analysis.
- Human multiple tissue expression array screening.
Main Results:
- Immunologically similar MUC15 proteins (approx. 130 kDa) were detected in ovine, caprine, porcine, and buffalo milk.
- Ovine and caprine MUC15 orthologs were confirmed in milk fat globule membranes.
- Human milk contains MUC15 (approx. 150 kDa), with abundant gene expression in placenta, salivary gland, thyroid, trachea, esophagus, kidney, testis, and K-562 cells.
- Moderate MUC15 expression was observed in pancreas, lung, lymph node, thymus, and brain.
Conclusions:
- MUC15 is conserved across multiple mammalian species and present in human milk.
- MUC15 exhibits broad tissue distribution, particularly in epithelial tissues and the placenta.
- Identified structural motifs suggest MUC15 is involved in signal transduction pathways, hinting at significant physiological roles.
