| First Author | Wang B | Year | 2020 |
| Journal | FASEB J | Volume | 34 |
| Issue | 4 | Pages | 5144-5161 |
| PubMed ID | 32043676 | Mgi Jnum | J:304933 |
| Mgi Id | MGI:6695373 | Doi | 10.1096/fj.201901693RR |
| Citation | Wang B, et al. (2020) Identification of the downstream molecules of agrin/Dok-7 signaling in muscle. FASEB J 34(4):5144-5161 |
| abstractText | The development of the neuromuscular junction depends on signaling processes that involve protein phosphorylation. Motor neuron releases agrin to activate muscle protein Dok-7, a key tyrosine kinase essential for the formation of a mature and functional neuromuscular junction. However, the signaling cascade downstream of Dok-7 remains poorly understood. In this study, we combined the clustered regularly interspaced short palindromic repeats/Cas9 technique and quantitative phosphoproteomics analysis to study the tyrosine phosphorylation events triggered by agrin/Dok-7. We found tyrosine phosphorylation level of 36 proteins increased specifically by agrin stimulation. In Dok-7 mutant myotubes, however, 13 of the 36 proteins failed to be enhanced by agrin stimulation, suggesting that these 13 proteins are Dok-7-dependent tyrosine-phosphorylated proteins, could work as downstream molecules of agrin/Dok-7 signaling. We validated one of the proteins, Anxa3, by in vitro and in vivo assays. Knocking down of Anxa3 in the cultured myotubes inhibited agrin-induced AChR clustering, whereas reduction of Anxa3 in mouse muscles induced abnormal postsynaptic development. Collectively, our phosphoproteomics analysis provides novel insights into the complicated signaling network downstream of agrin/Dok-7. |
