Endoplasmic reticulum-localized palmitoyltransferase that could catalyze the addition of palmitate onto various protein substrates and be involved in a variety of cellular processes (PubMed:23687301). Has a palmitoyltransferase activity toward NCDN and regulates NCDN association with endosome membranes through this palmitoylation (PubMed:23687301). May play a role in cell proliferation (By similarity). Has also a palmitoyltransferase activity-independent function in DNA virus-triggered and CGAS-mediated innate immune response (PubMed:29429998). Functions as an adapter that recruits IRF3 to STING1 to promote the activation of that key transcriptional regulator of type I interferon (IFN)-dependent immune response (PubMed:29429998). hexadecanoyl-CoA + L-cysteinyl-[protein] = CoA + S-hexadecanoyl-L-cysteinyl-[protein] Interacts with IRF3 and STING1; in presence of DNA viruses recruits IRF3 to STING1 promoting IRF3 phosphorylation and activation. The DHHC domain is required for palmitoyltransferase activity. Homozygous knockout mice are viable and do not show overt phenotype (PubMed:29429998). 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:29429998). Belongs to the DHHC palmitoyltransferase family.