Search

Selective and precise activation of signaling transduction cascades is key for cellular reprogramming and tissue regeneration. However, the development of small- or large-molecule agonists for many signaling pathways has remained elusive and is rate limiting to realize the full clinical potential of regenerative medicine. Focusing on the Wnt pathway, here we describe a series of disulfide-constrained peptides (DCPs) that promote Wnt signaling activity by modulating the cell surface levels of ZNRF3, an E3 ubiquitin ligase that controls the abundance of the Wnt receptor complex FZD/LRP at the plasma membrane. Mechanistically, monomeric DCPs induce ZNRF3 ubiquitination, leading to its cell surface clearance, ultimately resulting in FZD stabilization. Furthermore, we engineered multimeric DCPs that induce expansive growth of human intestinal organoids, revealing a dependence between valency and ZNRF3 clearance. Our work highlights a strategy for the development of potent, biologically active Wnt signaling pathway agonists via targeting of ZNRF3. [Display omitted] • Developed monomeric disulfide-constrained peptides (DCPs) to activate Wnt signaling • Highly specific DCPs against ZNRF3 induce its plasma membrane clearance • Inactive ZNRF3-DCP monomers are converted into potent agonists by multimerization • Potent and selective ZNRF3-DCPs support organoid growth Kschonsak et al. developed a series of disulfide-constrained peptides (DCPs) that bind to the E3 ubiquitin ligase ZNRF3, a negative regulator of the Wnt pathway. These peptides interfere with the ligase activity by inducing its internalization resulting in the activation of Wnt signaling and stimulation of intestinal organoid growth. [ABSTRACT FROM AUTHOR]