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Reviewed June 2013

What is the official name of the MUC1 gene?

The official name of this gene is “mucin 1, cell surface associated.”

MUC1 is the gene's official symbol. The MUC1 gene is also known by other names, listed below.

Read more about gene names and symbols on the About page.

What is the normal function of the MUC1 gene?

The MUC1 gene provides instructions for making a protein called mucin 1. This protein is one of several mucin proteins that make up mucus, a slippery substance that lubricates and protects the lining of the airways, digestive system, reproductive system, and other organs and tissues. In addition to its role in mucus, mucin 1 is involved in cell signaling and kidney development.

Although most mucin proteins are released from the cell, mucin 1 spans the cell membrane. It is found in epithelial cells, which are the cells that line the surfaces and cavities of the body. In particular, mucin 1 is found in the respiratory tract, female reproductive organs, and gastrointestinal tract. Like other mucins, mucin 1 has a region called the mucin domain that contains repeated stretches of protein building blocks (amino acids); the number of repeats can vary from 20 to 100. This protein is modified by the addition of numerous chains of sugar molecules, which are attached to certain amino acids in the mucin domain. The sugars spread out from the protein like branches on a tree and prevent access to the cell surface below, protecting the body from foreign invaders. The sugars also attract water molecules, helping lubricate and hydrate the tissues.

The portion of mucin 1 that reaches inside the cell, called the cytoplasmic tail (or MUC1-CT), relays signals from outside the cell to the cell's nucleus; these signals instruct the cell to undergo certain changes. Through this process, mucin 1 is thought to be involved in cell growth and division (proliferation), helping cells stick to one another (cell adhesion), cell movement (motility), and cell survival. The cytoplasmic tail can also detach from the cell membrane and move to the nucleus, although the mechanism is unclear. Some researchers suggest that, in the nucleus, MUC1-CT helps control the activity of other genes. In addition, mucin 1 is present in cells that form the kidneys and is thought to play a role in development of these organs.

Does the MUC1 gene share characteristics with other genes?

The MUC1 gene belongs to a family of genes called CD (CD molecules). It also belongs to a family of genes called MUC (mucins).

A gene family is a group of genes that share important characteristics. Classifying individual genes into families helps researchers describe how genes are related to each other. For more information, see What are gene families? in the Handbook.

How are changes in the MUC1 gene related to health conditions?

medullary cystic kidney disease type 1 - caused by mutations in the MUC1 gene

Mutations in the MUC1 gene cause medullary cystic kidney disease type 1 (MCKD1). This condition is characterized by impairment of kidney function that usually begins in adulthood and progressively worsens. Some affected individuals develop fluid-filled pockets in the kidneys called medullary cysts.

This condition occurs when a single DNA building block (nucleotide) called cytosine is inserted into the MUC1 gene. These insertions occur in one particular region of the gene, the part that provides instructions for the repeating mucin domain. These mutations lead to the production of an altered mucin 1 protein, although it is unclear how this change causes kidney disease. Why the effects of MUC1 gene mutations are limited to the kidneys is also unknown.

Where is the MUC1 gene located?

Cytogenetic Location: 1q21

Molecular Location on chromosome 1: base pairs 155,185,824 to 155,192,915

(Homo sapiens Annotation Release 107, GRCh38.p2) (NCBIThis link leads to a site outside Genetics Home Reference.)

The MUC1 gene is located on the long (q) arm of chromosome 1 at position 21.

The MUC1 gene is located on the long (q) arm of chromosome 1 at position 21.

More precisely, the MUC1 gene is located from base pair 155,185,824 to base pair 155,192,915 on chromosome 1.

See How do geneticists indicate the location of a gene? in the Handbook.

Where can I find additional information about MUC1?

You and your healthcare professional may find the following resources about MUC1 helpful.

You may also be interested in these resources, which are designed for genetics professionals and researchers.

What other names do people use for the MUC1 gene or gene products?

  • breast carcinoma-associated antigen DF3
  • CA 15-3
  • cancer antigen 15-3
  • carcinoma-associated mucin
  • CD227
  • DF3 antigen
  • EMA
  • episialin
  • H23AG
  • H23 antigen
  • KL-6
  • krebs von den Lungen-6
  • MAM6
  • MCD
  • MCKD
  • MUC-1
  • MUC-1/SEC
  • MUC-1/X
  • MUC1/ZD
  • mucin-1
  • mucin 1, transmembrane
  • peanut-reactive urinary mucin
  • PEM
  • PEMT
  • polymorphic epithelial mucin
  • PUM
  • tumor-associated epithelial membrane antigen
  • tumor associated epithelial mucin
  • tumor-associated mucin

Where can I find general information about genes?

The Handbook provides basic information about genetics in clear language.

These links provide additional genetics resources that may be useful.

What glossary definitions help with understanding MUC1?

acids ; Ca ; cancer ; carcinoma ; cell ; cell adhesion ; cell membrane ; cystic kidney ; cysts ; cytosine ; digestive ; digestive system ; DNA ; domain ; epithelial ; gastrointestinal ; gene ; kidney ; mucus ; nucleotide ; nucleus ; proliferation ; protein ; respiratory ; transmembrane ; tumor

You may find definitions for these and many other terms in the Genetics Home Reference Glossary.

See also Understanding Medical Terminology.

References (7 links)


The resources on this site should not be used as a substitute for professional medical care or advice. Users seeking information about a personal genetic disease, syndrome, or condition should consult with a qualified healthcare professional. See How can I find a genetics professional in my area? in the Handbook.

Reviewed: June 2013
Published: February 8, 2016