E3 ubiquitin-protein ligase that acts as a negative regulator of the Wnt signaling pathway by mediating the ubiquitination, endocytosis and subsequent degradation of Wnt receptor complex components Frizzled. Acts on both canonical and non-canonical Wnt signaling pathway (PubMed:18313049, PubMed:22575959, PubMed:22895187). Along with RSPO2 and ZNRF3, constitutes a master switch that governs limb specification (By similarity). {ECO:0000250|UniProtKB:P0DPR2, ECO:0000269|PubMed:18313049, ECO:0000269|PubMed:22575959, ECO:0000269|PubMed:22895187}. This is the function of Ensembl gene identifier ENSG00000108375 (RNF43, ring finger protein 43).