Plakophilins in Desmosomal Adhesion and Signaling

• Published in: Cell communication & adhesion 2014-02, Vol.21 (1), p.25-42
• Main Authors: Hatzfeld, Mechthild, Wolf, Annika, Keil, René
• Format: Article
• Language: English
• Subjects: Animals; armadillo protein; beta Catenin - metabolism; Cell Adhesion; desmosome; Desmosomes - metabolism; Humans; Neoplasms - metabolism; Neoplasms - pathology; phosphorylation; plakophilin; Plakophilins - chemistry; Plakophilins - genetics; Plakophilins - metabolism; post-translational modification; rho GTP-Binding Proteins - metabolism; Rho-signaling; scaffold; Signal Transduction; translation
• ISSN: 1541-9061; 1543-5180
• DOI: 10.3109/15419061.2013.876017

Abstract The regulation of adhesion and growth is important for epithelial function and dysfunction. β-catenin (armadillo in Drosophila) is the prototype of a multifunctional molecule that regulates cell adhesion via adherens junctions and cell signaling via LEF/TCF transcription factors. Desmosomal armadillo proteins comprise plakoglobin and the plakophilins 1, 2, and 3. These proteins are essential for building up the desmosome and linking the desmosomal cadherins to keratin filaments. High expression of plakophilins in desmosomes correlates with strong intercellular cohesion and is essential for tissue integrity under mechanical stress. However, like β-catenin, these proteins have diverse non-desmosomal functions, for example, in regulating actin organization, protein synthesis, and growth control. In line with these functions, their de-regulated expression with up- as well as down-regulation has been connected to cancer and metastasis. Now, recent evidence sheds light on the post-translational regulation and provides an explanation for how de-regulation of plakophilins can contribute to cancer.