The ternary complex containing UFD1, VCP and NPLOC4 binds ubiquitinated proteins and is necessary for the export of misfolded proteins from the ER to the cytoplasm, where they are degraded by the proteasome. The NPLOC4-UFD1-VCP complex regulates spindle disassembly at the end of mitosis and is necessary for the formation of a closed nuclear envelope (PubMed:10811609, PubMed:11740563, PubMed:11781570, PubMed:12411482, PubMed:12644454, PubMed:14636562). Acts as a negative regulator of type I interferon production via the complex formed with VCP and UFD1, which binds to DDX58/RIG-I and recruits RNF125 to promote ubiquitination and degradation of DDX58/RIG-I (By similarity). Protein degradation; proteasomal ubiquitin-dependent pathway. Heterodimer with UFD1 (PubMed:10811609, PubMed:12644454). The heterodimer binds ubiquitinated proteins (PubMed:12644454). The heterodimer binds to VCP and inhibits Golgi membrane fusion (PubMed:10811609, PubMed:12644454). Interacts with ZFAND2B; probably through VCP (By similarity). Associated with the endoplasmic reticulum and nuclear. Binds ubiquitinated proteins via its RanBP2-type zinc finger. Belongs to the NPL4 family.