Protein-serine O-palmitoleoyltransferase that acts as a key regulator of the Wnt signaling pathway by mediating the attachment of palmitoleate, a 16-carbon monounsaturated fatty acid (C16:1(9Z)), to Wnt proteins. Serine palmitoleoylation of WNT proteins is required for efficient binding to frizzled receptors. {ECO:0000250|UniProtKB:Q9JJJ7, ECO:0000269|PubMed:12034504, ECO:0000269|PubMed:20826466, ECO:0000269|PubMed:24292069}. This is the function of Ensembl gene identifier ENSG00000102312 (PORCN, porcupine O-acyltransferase).