Endoplasmic reticulum-localized palmitoyltransferase that could catalyze the addition of palmitate onto various protein substrates and be involved in a variety of cellular processes (By similarity). Has a palmitoyltransferase activity toward NCDN and regulates NCDN association with endosome membranes through this palmitoylation (By similarity). May play a role in cell proliferation (PubMed:28331227). Has also a palmitoyltransferase activity-independent function in DNA virus-triggered and CGAS-mediated innate immune response (PubMed:28331227). 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:28331227). 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. Expressed in testis. The DHHC domain is required for palmitoyltransferase activity. Belongs to the DHHC palmitoyltransferase family.