JUP

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What is the official name of the JUP gene?

The official name of this gene is “junction plakoglobin.”

JUP is the gene's official symbol. The JUP 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 JUP gene?

The JUP gene provides instructions for making a protein called plakoglobin. This protein is found primarily in cells of the heart and skin, where it is part of two specialized structures called adherens junctions and desmosomes. Both of these structures help hold neighboring cells together, which provides strength and stability to tissues. Desmosomes may also be involved in other critical cell functions, including chemical signaling pathways, the process by which cells mature to perform specific functions (differentiation), and the self-destruction of cells (apoptosis).

Studies suggest that plakoglobin also plays a role in signaling within cells as part of the WNT pathway. WNT signaling controls the activity of certain genes and regulates the interactions between cells. This signaling pathway is involved in many aspects of development, including the normal development of the heart, skin, and hair.

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

keratoderma with woolly hair - caused by mutations in the JUP gene: Several mutations in the JUP gene have been found to cause a form of keratoderma with woolly hair classified as type I. This form of the condition is also known as Naxos disease. It is characterized by thick, calloused skin on the palms of the hands and soles of the feet (palmoplantar keratoderma); coarse, dry, fine, tightly curled, and sometimes sparse hair; and a potentially life-threatening form of heart disease called arrhythmogenic right ventricular cardiomyopathy (ARVC).
The JUP gene mutations that cause keratoderma with woolly hair type I lead to the production of an abnormally short version of the plakoglobin protein. The abnormal plakoglobin does not interact appropriately with other desmosomal proteins, which alters the structure of desmosomes and prevents cells from attaching to one another effectively. Researchers suspect that the impaired connections between cells make the skin, hair, and heart muscle more fragile. Over time, as these tissues are exposed to mechanical stress (for example, friction on the surface of the skin or the constant contraction and relaxation of the heart muscle), they become damaged and can no longer function normally. This mechanism probably underlies the skin, hair, and heart problems that occur in keratoderma with woolly hair type I.
Studies suggest that the abnormally short plakoglobin also impairs WNT signaling, which appears to cause heart muscle cells to be replaced with fat cells over time. This abnormal signaling may influence the development of ARVC in affected individuals.
other disorders - caused by mutations in the JUP gene: JUP gene mutations have also been found to cause a spectrum of signs and symptoms that overlap with those of keratoderma with woolly hair type I (described above). Some affected families have had similar skin and hair abnormalities but no apparent heart problems, while others have had ARVC only, with normal skin and hair. Although these conditions are related to impaired function of plakoglobin and abnormal desmosomes, it is unclear how mutations in this gene lead to these different patterns of features.
At least one mutation in the JUP gene can cause a disorder known as lethal congenital epidermolysis bullosa (LCEB). Features of this condition include very fragile skin that blisters and detaches easily, a complete absence of hair (alopecia), and abnormal fingernails. The skin abnormalities lead to a severe loss of fluids and death in early infancy. The mutation found to cause LCEB, written as Gln539Ter or Q539X, prevents the production of any functional plakoglobin. As a result, the skin has no stable desmosomes, so skin cells are unable to attach to one another effectively. Because affected individuals die before heart disease may become apparent, it is unknown whether a complete loss of plakoglobin also impairs desmosomes in the heart.

Genetics Home Reference provides information about arrhythmogenic right ventricular cardiomyopathy, which is also associated with changes in the JUP gene.

Where is the JUP gene located?

Cytogenetic Location: 17q21

Molecular Location on chromosome 17: base pairs 41,754,607 to 41,786,712

The JUP gene is located on the long (q) arm of chromosome 17 at position 21.

More precisely, the JUP gene is located from base pair 41,754,607 to base pair 41,786,712 on chromosome 17.

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

Where can I find additional information about JUP?

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

Educational resources - Information pages (2 links)
Gene Reviews - Clinical summary
Genetic Testing Registry - Repository of genetic test information (1 link)

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

PubMed - Recent literature
OMIM - Genetic disorder catalog (2 links)
Research Resources - Tools for researchers (5 links)

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

ARVD12
catenin (cadherin-associated protein), gamma 80kDa
CTNNG
desmoplakin-3
desmoplakin III
DP3
DPIII
PDGB
PKGB
plakoglobin

See How are genetic conditions and genes named? in the Handbook.

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 JUP?

alopecia ; apoptosis ; cardiomyopathy ; cell ; congenital ; contraction ; differentiation ; fat cells ;gene ; intermediate filaments ; keratoderma ; muscle cells ; mutation ; palmoplantar keratoderma ;protein ; spectrum ; stress

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

References (8 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