Palmitoyltransferase that could catalyze the addition of palmitate onto various protein substrates (PubMed:23687301). Has a palmitoyltransferase activity toward NCDN and regulates NCDN association with endosome membranes through this palmitoylation (PubMed:23687301). 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. Expressed at high levels in fetal lung and heart. Expressed at lower levels in fetal liver and brain. Also detected in adult islet cells of pancreas, Leydig cells of testis, retina and molecular layer of cerebellum. The DHHC domain is required for palmitoyltransferase activity. Homozygous knockout mice are viable, fertile and do not display overt phenotype (PubMed:25299331). Composition and number of major immune cells is normal but mice are more susceptible to DNA-virus infection and death than their wild-type counterpart (PubMed:25299331). Belongs to the DHHC palmitoyltransferase family.