β-Catenin Interacts with MyoD and Regulates Its Transcription Activity

Abstract

Wnt regulation of muscle development is thought to be mediated by the β-catenin-TCF/LEF-dependent canonical pathway. Here we demonstrate that β-catenin, not TCF/LEF, is required for muscle differentiation. We showed that β-catenin interacts directly with MyoD, a basic helix-loop-helix transcription factor essential for muscle differentiation and enhances its binding to E box elements and transcriptional activity. MyoD-mediated transactivation is inhibited in muscle cells when β-catenin is deficient or the interaction between MyoD and β-catenin is disrupted. These results demonstrate that β-catenin is necessary for MyoD function, identifying MyoD as an effector in the Wnt canonical pathway.

SUPPLEMENTAL MATERIAL

Supplemental material for this article may be found at http://mcb.asm.org/ .

ACKNOWLEDGMENTS

This work was supported in part by grants from the NIH (L.M. and W.C.X.) and Muscular Dystrophy Association (L.M.).

We are grateful to Xi He (Harvard Medical School) and Xian Yu (Institute of Neuroscience, Shanghai, China) for valuable constructs and reagents.