part of has part endoplasmic reticulum membrane VCP-NPL4-UFD1 AAA ATPase complex cellular_component p97-Ufd1-Npl4 complex GO:0034098 A multiprotein ATPase complex required for the efficient dislocation of ER-lumenal degradation substrates, and their subsequent proteolysis by the proteasome. In budding yeast, this complex includes Cdc48p, Npl4p and Ufd1p proteins. In mammals, this complex includes a hexamer of VCP/p97 (a cytosolic ATPase) and trimers of each of its cofactors UFD1L and NPL4 (NPLOC4) (e.g. a 6:3:3 stoichiometry). Cdc48p-Npl4p-Ufd1p AAA ATPase complex UFD1-NPL4 complex membrane protein complex endoplasmic reticulum protein-containing complex