Golgi-localized palmitoyltransferase that catalyzes the addition of palmitate onto various protein substrates (PubMed:15229235, PubMed:15603741, PubMed:16129400, PubMed:19001095, PubMed:23793055, PubMed:25253725, PubMed:26487721). Has no stringent fatty acid selectivity and in addition to palmitate can also transfer onto target proteins myristate from tetradecanoyl-CoA and stearate from octadecanoyl-CoA (Probable). Plays an important role in G protein-coupled receptor signaling pathways involving GNAQ and potentially other heterotrimeric G proteins by regulating their dynamic association with the plasma membrane (PubMed:19001095). Palmitoylates ITGA6 and ITGB4, thereby regulating the alpha-6/beta-4 integrin localization, expression and function in cell adhesion to laminin (By similarity). Plays a role in the TRAIL-activated apoptotic signaling pathway most probably through the palmitoylation and localization to the plasma membrane of TNFRSF10A (By similarity). In the brain, by palmitoylating the gamma subunit GABRG2 of GABA(A) receptors and regulating their postsynaptic accumulation, plays a role in synaptic GABAergic inhibitory function and GABAergic innervation (PubMed:15229235, PubMed:17151279, PubMed:27875292). Palmitoylates the neuronal protein GAP43 which is also involved in the formation of GABAergic synapses (PubMed:27875292). Palmitoylates NCDN thereby regulating its association with endosome membranes (PubMed:23687301). Probably palmitoylates PRCD and is involved in its proper localization within the photoreceptor (PubMed:27613864). Could mediate the palmitoylation of NCAM1 and regulate neurite outgrowth (PubMed:27247265). Could palmitoylate DNAJC5 and regulate its localization to Golgi membranes (PubMed:18596047). Also constitutively palmitoylates DLG4 (PubMed:15603741). May also palmitoylate SNAP25 (PubMed:25253725). Could palmitoylate the glutamate receptors GRIA1 and GRIA2 but this has not been confirmed in vivo (PubMed:16129400, PubMed:27875292). Could also palmitoylate the D(2) dopamine receptor DRD2 (By similarity). May also function as a calcium transporter. hexadecanoyl-CoA + L-cysteinyl-[protein] = CoA + S-hexadecanoyl-L-cysteinyl-[protein] L-cysteinyl-[protein] + tetradecanoyl-CoA = CoA + S-tetradecanoyl-L-cysteinyl-[protein] L-cysteinyl-[protein] + octadecanoyl-CoA = CoA + S-octadecanoyl-L-cysteinyl-[protein] Monomer (PubMed:23793055). Homooligomers (PubMed:17151279, PubMed:23793055). The monomeric form has a higher catalytic activity (PubMed:23793055). Forms heterooligomers with ZDHHC7 (PubMed:17151279). Interacts with TNFRSF10A (By similarity). Localizes to the Golgi cis cisterna. Widely expressed, with highest levels in brain. In the brain, expressed only in neurons (at protein level). The DHHC domain is required for palmitoyltransferase activity. Phosphorylation by FGFR1 and SRC probably regulates the palmitoyltransferase activity. Autopalmitoylated. Homozygous knockout mice are viable, fertile and do not display overt phenotype (PubMed:27875292). Male show a modest reduction in body weight (PubMed:27875292). Zdhhc3 and Zdhhc7 double knockout mice show a perinatally lethal phenotype (PubMed:27875292). Belongs to the DHHC palmitoyltransferase family.