JUP Gene

The JUP gene on chromosome 17q21.2 (JUP stands for junction plakoglobin) encodes the important cytoplasmic protein PLakoglobin. Plakoglobin (synonyms: junction plakoglobin, γ-catenin) belongs to the catenin family because it contains a specific repeating amino acid motif (Armadillo repeat). Plakoglobin is a structural protein of cell contacts such as desmosomes and adherens junctions. It is homologous to beta-catenin and binds to cell contacts on the cytosolic side and links cadherins to the cytoskeleton.

Plakoglobin forms various complexes with cadherins and desmosomal cadherins and belongs to the catenin family because it contains a specific repeating amino acid motif (Armadillo repeat).

Diseases associated with JUP include:

• Naxos diseasea diffuse palmoplantar keratosis with familial arrhythmogenic right ventricular dysplasia.
• arrhythmogenic right ventricular cardiomyopathy
• Ectodermal dysplasia-skin fragility syndrome

The biological activities of the encoded protein relate to protein homodimerization activities and protein kinase binding. An important paralog of this gene is CTNNB1.

The membrane-associated plaques are architectural elements in an important strategic position to influence the arrangement and function of both the cytoskeleton and cells within the tissue. The presence of plakoglobin in both desmosomes and intermediates suggests that it plays a central role in the structure and function of submembranous plaques. Plakoglobin acts as a substrate for VE-PTP and is required by it to stimulate VE-cadherin function in endothelial cells. May substitute for beta-catenin in E-cadherin/catenin adhesion complexes designed to couple cadherins to the actin cytoskeleton.

1. Broussard JA et al.( 2015) Desmosome regulation and signaling in disease, Cell Tissue Res 360: 501-512.
2. Corrado D et al. (2015) Treatment of arrhythmogenic right ventricular cardiomyopathy/dysplasia: an international task force consensus statement. Available online. Accessed 5-24-21.
3. Holthöfer B et al (2007) Structure and function of desmosomes. Int Rev Cytol 264:65-163.
4. Li D et al. (2011) Restrictive loss of plakoglobin in cardiomyocytes leads to arrhythmogenic cardiomyopathy. Hum Mol Genet 20:4582-4596.
5. McNally E et al (2017) Arrhythmogenic right ventricular cardiomyopathy In: Adam MP et al editors. GeneReviews University of Washington, Seattle; 1993-2021.
6. Sonsöz MR et al (2021) A Rare Cause of Syncope: Naxos Disease Caused by Novel Homozygous Deletion in the JUP Gene. Circ Cardiovasc Imaging 14:e013059.