N-cadherin Activation Substitutes for the Cell Contact Control in Cell Cycle Arrest and Myogenic Differentiation

• Published in: The Journal of biological chemistry Vol. 279; no. 35; pp. 36795 - 36802
• Main Authors: Julie Gavard, Véronique Marthiens, Céline Monnet, Mireille Lambert, René Marc Mège
• Format: Journal Article
• Language: English
• Published: American Society for Biochemistry and Molecular Biology 01.08.2004
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1074/jbc.M401705200

N-cadherin is expressed throughout skeletal myogenesis and has been proposed to be involved in the differentiation program of myogenic precursors. Here, we further characterize the N-cadherin involvement and its mechanism of action at the onset of differentiation, through controlled N-cadherin activation by plating isolated C2 myoblasts on surfaces coated with a chimeric Ncad-Fc homophilic ligand (N-cadherin ectodomain fused to the immunoglobulin G Fc fragment). We show that N-cadherin activation substitutes for the cell density in myogenic differentiation by promoting myogenin and troponin T expression. In addition, N-cadherin adhesion participates to the associated cell cycle arrest through the nuclear accumulation of cyclin-dependent kinase inhibitors p21 and p27. Mouse primary myoblast cultures exhibited similar responses to N-cadherin as C2 cells. RNA interference knockdowns of the N-cadherin-associated cytoplasmic proteins p120 and β-catenin produced opposite effects on the differentiation pathway. p120 silencing resulted in a decreased myogenic differentiation, associated with a reduction in cadherin-catenin content, which may explain its action on myogenic differentiation. β-Catenin silencing led to a stimulatory effect on myogenin expression, without any effect on cell cycle. Our results demonstrate that N-cadherin adhesion may account for cell-cell contact-dependent cell cycle arrest and differentiation of myogenic cells, involving regulation through p120 and β-catenins.