Palmitoyltransferase that could catalyze the addition of palmitate onto various protein substrates (By similarity). Has a palmitoyltransferase activity toward NCDN and regulates NCDN association with endosome membranes through this palmitoylation. Has also a palmitoyltransferase activity-independent function in DNA virus-triggered and CGAS-mediated innate immune response (PubMed:25299331). Functions as an activator of STING1 by promoting its cGAMP-induced oligomerization and the recruitment of downstream signaling components (PubMed:25299331). hexadecanoyl-CoA + L-cysteinyl-[protein] = CoA + S-hexadecanoyl-L-cysteinyl-[protein] Interacts with STING1; ZDHHC1 constitutively interacts with STING1 and in presence of DNA viruses activates it by promoting its cGAMP-induced oligomerization and the recruitment of downstream signaling components. Widely expressed with significant expression in heart, brain, placenta, lung, liver, kidney, testis, thymus and small intestine (PubMed:16647879). Expressed at lower levels in adult pancreas and lung (PubMed:10395086). Expressed at high levels in fetal lung, kidney and heart. The DHHC domain is required for palmitoyltransferase activity. Belongs to the DHHC palmitoyltransferase family.