YAP promotes myogenic differentiation via the MEK5-ERK5 pathway

FASEB J. 2017 Jul;31(7):2963-2972. doi: 10.1096/fj.201601090R. Epub 2017 Mar 29.

Abstract

Yes-associated protein (YAP) is a transcriptional coactivator in the Hippo pathway that regulates cell proliferation, differentiation, and apoptosis. The MEK5/ERK5 MAPK cascade is essential for the early step of myogenesis. In this study, we generated C2C12 stable cell lines that expressed YAP (C2C12-YAP cells) and found that ERK5 and MEK5 were activated in C2C12-YAP cells compared with control C2C12 (C2C12-vector) cells. C2C12-YAP stable cells also differentiated into myotubes better than C2C12-vector cells, and expressed elevated levels of myogenin, a transcription factor that regulates myogenesis, as well as elevated levels of myosin heavy chain, a skeletal muscle marker. Western blot analysis revealed that Src and c-Abl (Abelson murine leukemia viral oncogene homolog 1) activation were enhanced in C2C12-YAP cells. Conversely, treatment of inhibitors of c-Abl, Src, or MEK5 inhibited activation of MEK5 and ERK5 and myogenesis of C2C12 myoblasts. Specific interactions between YAP and proteins in the ERK5 pathway, such as MEK kinase 3 (MEKK3) and ERK5, were illustrated by coimmunoprecipitation experiments. MEKK3 contains the PPGY motif (aa 178-181), which may interact with YAP. Site-directed mutagenesis experiments revealed that expression of MEKK3 Y181F mutant inhibited MEK5/ERK5 activation and myogenic differentiation. These results suggest that YAP promotes muscle differentiation by activating the Abl/Src/MEKK3/MEK5/ERK5 kinase cascade.-Chen, T.-H., Chen, C.-Y., Wen, H.-C., Chang, C.-C., Wang, H.-D., Chuu, C.-P., Chang, C.-H. YAP promotes myogenic differentiation via the MEK5-ERK5 pathway.

Keywords: Abl; C2C12 myoblasts; Src; TAZ; myogenesis.

MeSH terms

  • Adaptor Proteins, Signal Transducing / genetics
  • Adaptor Proteins, Signal Transducing / metabolism*
  • Animals
  • Cell Cycle Proteins
  • Cell Differentiation
  • Cell Line
  • Cytoplasm
  • Gene Expression Regulation / physiology*
  • Genes, abl
  • MAP Kinase Kinase 5 / genetics
  • MAP Kinase Kinase 5 / metabolism*
  • MAP Kinase Kinase Kinase 3 / genetics
  • MAP Kinase Kinase Kinase 3 / metabolism
  • Mice
  • Mitogen-Activated Protein Kinase 7 / genetics
  • Mitogen-Activated Protein Kinase 7 / metabolism*
  • Muscle Development / physiology
  • Muscle Fibers, Skeletal / metabolism
  • Phosphoproteins / genetics
  • Phosphoproteins / metabolism*
  • Protein Transport
  • YAP-Signaling Proteins
  • src-Family Kinases

Substances

  • Adaptor Proteins, Signal Transducing
  • Cell Cycle Proteins
  • Phosphoproteins
  • YAP-Signaling Proteins
  • Yap1 protein, mouse
  • src-Family Kinases
  • Mitogen-Activated Protein Kinase 7
  • MAP Kinase Kinase Kinase 3
  • Map3k3 protein, mouse
  • MAP Kinase Kinase 5
  • Map2k5 protein, mouse