Palmitoyltransferase that catalyzes the addition of palmitate onto protein substrates including the D(2) dopamine receptor DRD2, GSK3B or MAVS. Mediates GSK3B palmitoylation to prevent its AKT1- mediated phosphorylation leading to activation of the STAT3 signaling pathway (PubMed:35606353). Also catalyzes MAVS palmitoylation which promotes its stabilization and activation by inhibiting 'Lys-48'- but facilitating 'Lys-63'-linked ubiquitination (PubMed:38016475). {ECO:0000269|PubMed:26535572, ECO:0000269|PubMed:35606353, ECO:0000269|PubMed:38016475}. This is the function of ENSG00000136247 (ZDHHC4, zDHHC palmitoyltransferase 4).