A unique and specific interaction between αT-catenin and plakophilin-2 in the area composita, the mixed-type junctional structure of cardiac intercalated discs
Author:
Goossens Steven12, Janssens Barbara12, Bonné Stefan12, De Rycke Riet12, Braet Filip12, van Hengel Jolanda12, van Roy Frans12
Affiliation:
1. Department for Molecular Biomedical Research, VIB, Ghent University, B-9052 Ghent, Belgium 2. Department of Molecular Biology, Ghent University, B-9052 Ghent, Belgium
Abstract
Alpha-catenins play key functional roles in cadherin-catenin cell-cell adhesion complexes. We previously reported on αT-catenin, a novel member of the α-catenin protein family. αT-catenin is expressed predominantly in cardiomyocytes, where it colocalizes with αE-catenin at the intercalated discs. Whether αT- and αE-catenin have specific or synergistic functions remains unknown. In this study we used the yeast two-hybrid approach to identify specific functions of αT-catenin. An interaction between αT-catenin and plakophilins was observed and subsequently confirmed by co-immunoprecipitation and colocalization. Interaction with the amino-terminal part of plakophilins appeared to be specific for the central `adhesion-modulation' domain of αT-catenin. In addition, we showed, by immuno-electron microscopy, that desmosomal proteins in the heart localize not only to the desmosomes in the intercalated discs but also at adhering junctions with hybrid composition. We found that in the latter junctions, endogenous plakophilin-2 colocalizes with αT-catenin. By providing an extra link between the cadherin-catenin complex and intermediate filaments, the binding of αT-catenin to plakophilin-2 is proposed to be a means of modulating and strengthening cell-cell adhesion between cardiac muscle cells. This could explain the devastating effect of plakophilin-2 mutations on cell junction stability in intercalated discs, which lead to cardiac muscle malfunction.
Publisher
The Company of Biologists
Reference56 articles.
1. Abe, K., Chisaka, O., van Roy, F. and Takeichi, M. (2004). Stability of dendritic spines and synaptic contacts is controlled by alpha N-catenin. Nat. Neurosci.7, 357-363. 2. Awad, M. M., Dalal, D., Cho, E., Amat-Alarcon, N., James, C., Tichnell, C., Tucker, A., Russell, S. D., Bluemke, D. A., Dietz, H. C. et al. (2006a). DSG2 mutations contribute to arrhythmogenic right ventricular dysplasia/cardiomyopathy. Am. J. Hum. Genet.79, 136-142. 3. Awad, M. M., Dalal, D., Tichnell, C., James, C., Tucker, A., Abraham, T., Spevak, P. J., Calkins, H. and Judge, D. P. (2006b). Recessive arrhythmogenic right ventricular dysplasia due to novel cryptic splice mutation in PKP2. Hum. Mutat.27, 1157. 4. Bienz, K., Egger, D. and Pasamontes, L. (1986). Electron-microscopic immunocytochemistry - silver enhancement of colloidal gold marker allows double labeling with the same primary antibody. J. Histochem. Cytochem.34, 1337-1342. 5. Bierkamp, C., McLaughlin, K. J., Schwarz, H., Huber, O. and Kemler, R. (1996). Embryonic heart and skin defects in mice lacking plakoglobin. Dev. Biol.180, 780-785.
Cited by
102 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献
|
|