Molecular mechanism of Activin receptor inhibition by DLK1.
Antfolk, D., Ming, Q., Manturova, A., Goebel, E.J., Thompson, T.B., Luca, V.C.(2025) Nat Commun 16: 5976-5976
- PubMed: 40593645 
- DOI: https://doi.org/10.1038/s41467-025-60634-3
- Primary Citation of Related Structures:  
9D20 - PubMed Abstract: 
Delta-like non-canonical Notch ligand 1 (DLK1) influences myogenesis, adipogenesis, and other aspects of human development through a process that is largely attributed to the downregulation of Notch signaling. Here, we show that DLK1 does not bind to Notch receptors or affect ligand-mediated Notch activation, but instead engages the TGF-β superfamily member Activin receptor type 2B (ACVR2B). The crystal structure of the DLK1-ACVR2B complex reveals that DLK1 mimics the binding mode of canonical TGF-β ligands to compete for access to ACVR2B. In functional assays, DLK1 antagonizes Myostatin-ACVR2B signaling to promote myoblast differentiation, rationalizing a mechanism for the role of DLK1 in muscle development and regeneration. Crosstalk between Notch and TGF-β is mediated by interactions between the transcriptional regulators SMAD2/3 and the Notch intracellular domain (NICD), and DLK1 inhibits SMAD2/3-NICD colocalization. These findings indicate that DLK1 acts directly on ACVR2B to inhibit signaling, whereas the observed effects on Notch may be an indirect result of DLK1 interference with NICD-SMAD complex formation.
- Department of Immunology, Moffitt Cancer Center & Research Institute, Tampa, FL, USA.
Organizational Affiliation: 

















