MUC1 Gene: Structure, Function, and Clinical Significance
A comprehensive guide to the MUC1 gene, its protein product, associated diseases, and expression patterns.
Gene Information Card
| Symbol | MUC1 |
|---|---|
| Full Name | Mucin 1, cell surface associated |
| Gene Type | protein coding |
| Chromosomal Location | 1q22 |
| NCBI Gene ID | 4582 ncbi.nlm.nih.gov/gene/4582 |
| Ensembl ID | ENSG00000185499 |
| UniProt ID | P15941 |
| OMIM ID | 158340 |
| HGNC ID | 7508 |
| Aliases | CA 15-3, CD227, EMA, H23AG, KL-6, MUC-1, MUC1D, PEM, PEMT |
Description
The MUC1 gene encodes mucin 1, a transmembrane glycoprotein with a large extracellular domain heavily O-glycosylated. It is expressed on the apical surface of many epithelial cells, where it provides a protective barrier. MUC1 is involved in cell signaling, immune modulation, and adhesion. Aberrant expression and glycosylation are common in various cancers, making it a tumor marker and therapeutic target. Mutations in MUC1 are also linked to a rare form of tubulointerstitial kidney disease.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Breast cancer | Overexpression and aberrant glycosylation of MUC1 promote oncogenic signaling, inhibit apoptosis, and facilitate immune evasion. | COSMIC; NCBI Gene; multiple studies |
| Pancreatic cancer | MUC1 overexpression contributes to tumor progression, invasion, and metastasis through interaction with beta-catenin and EGFR pathways. | COSMIC; NCBI Gene |
| Colorectal cancer | Altered MUC1 expression is associated with poor prognosis and increased metastatic potential. | COSMIC; NCBI Gene |
| Ovarian cancer | MUC1 is overexpressed and serves as a serum biomarker (CA 15-3) for monitoring. | COSMIC; NCBI Gene |
| Medullary cystic kidney disease type 1 (MCKD1) | Specific frameshift mutations in the variable number tandem repeat (VNTR) region lead to production of a neopeptide that accumulates in the kidney, causing tubulointerstitial fibrosis. | OMIM; ClinVar |
| Tubulointerstitial nephritis and uveitis syndrome (TINU) | MUC1 mutations are implicated in some cases, leading to renal dysfunction. | ClinVar; OMIM |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Breast | High | High |
| Lung | Medium | Medium |
| Colon | High | High |
| Kidney | Medium | Medium |
| Stomach | High | High |
| Pancreas | Medium | Medium |
| Ovary | Medium | Medium |
| Liver | Low | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| MCF7 (breast cancer) | High | Overexpressed; used as model for MUC1 studies |
| MDA-MB-231 (breast cancer) | Medium | Triple-negative; lower expression than MCF7 |
| A549 (lung cancer) | Medium | Expressed; involved in tumor progression |
| PANC-1 (pancreatic cancer) | High | Overexpressed; associated with aggressive phenotype |
| HeLa (cervical cancer) | Low | Low endogenous expression |
| HEK293 (embryonic kidney) | Low | Used for recombinant expression studies |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.27dupC (p.Leu10Profs*94) | Frameshift | Rare | Causes MCKD1; produces truncated protein with neopeptide |
| c.428dupC (p.Leu144Profs*94) | Frameshift | Rare | Causes MCKD1; similar mechanism |
| VNTR length polymorphism | Copy number variant | Common | Affects glycosylation and immunogenicity; linked to cancer risk |
| Missense variants (e.g., p.Thr27Ala) | Missense | Low | Functional impact unclear; may alter glycosylation sites |
Mutation functional classification
Loss of Function (LOF)
Loss-of-function mutations are rare; complete loss of MUC1 is not commonly observed in cancers, but reduced expression may affect cell adhesion and immune recognition.
Gain of Function (GOF)
Gain-of-function is common in cancers via overexpression and altered glycosylation, leading to enhanced oncogenic signaling and metastasis.
Dominant Negative (DN)
Frameshift mutations in the VNTR region produce a neopeptide that may exert a dominant-negative effect by accumulating in the endoplasmic reticulum and causing cellular stress, as seen in MCKD1.
View complete mutation data：
Gene Ontology (GO)
| • extracellular region | • plasma membrane |
| • extracellular exosome | • protein binding |
| • carbohydrate binding | • signal transducer activity |
| • cell adhesion | • innate immune response |
| • negative regulation of apoptotic process | • positive regulation of cell proliferation |
Pathways
• ErbB signaling pathway
• Wnt signaling pathway
• PI3K-Akt signaling pathway
• MAPK signaling pathway
• Cell adhesion molecules (CAMs)
• Pathways in cancer
Protein Summary
MUC1 is a type I transmembrane glycoprotein with a large extracellular domain composed of variable number tandem repeats (VNTRs) rich in serine, threonine, and proline, which are heavily O-glycosylated. The protein undergoes autocleavage into alpha and beta subunits that remain non-covalently associated. The extracellular domain can be shed into the bloodstream (CA 15-3 antigen). Intracellularly, the cytoplasmic tail contains multiple phosphorylation sites that interact with signaling molecules such as beta-catenin, EGFR, and Src. MUC1 plays roles in cell protection, lubrication, and signal transduction. In cancer, aberrant overexpression and glycosylation promote tumor progression and immune evasion.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| MUC12 Knockout HEK293 Cell Line | EDJ-KQ3011 | Human | 10071 | Details Get a Quote |
| MUC17 Knockout HEK293 Cell Line | EDJ-KQ9761 | Human | 140453 | Details Get a Quote |
| MUC15 Knockout HEK293 Cell Line | EDJ-KQ10390 | Human | 143662 | Details Get a Quote |
| MUC13 Knockout HEK293 Cell Line | EDJ-KQ12078 | Human | 56667 | Details Get a Quote |
| MUC19 Knockout HEK293 Cell Line | EDJ-KQ12108 | Human | 283463 | Details Get a Quote |
| MUC16 Knockout HEK293 Cell Line | EDJ-KQ17726 | Human | 94025 | Details Get a Quote |
| MUC12 Knockout HeLa Cell Line | EDJ-KQ24214 | Human | 10071 | Details Get a Quote |
| MUC16 Knockout HeLa Cell Line | EDJ-KQ19801 | Human | 94025 | Details Get a Quote |
| MUC12 Knockout A-549 Cell Line | EDJ-KQ22845 | Human | 10071 | Details Get a Quote |
| MUC13 Knockout A-549 Cell Line | EDJ-KQ40732 | Human | 56667 | Details Get a Quote |
| MUC1 Knockout HeLa Cell Line | EDJ-KQ53922 | Human | 4582 | Details Get a Quote |
| MUC13 Knockout HeLa Cell Line | EDJ-KQ56748 | Human | 56667 | Details Get a Quote |
| MUC17 Knockout HeLa Cell Line | EDJ-KQ58430 | Human | 140453 | Details Get a Quote |
| MUC15 Knockout HeLa Cell Line | EDJ-KQ58492 | Human | 143662 | Details Get a Quote |
| MUC1 Knockout A-549 Cell Line | EDJ-KQ62415 | Human | 4582 | Details Get a Quote |
