Function: Adapter protein required for Golgi and endoplasmic reticulum biogenesis. Involved in Golgi and endoplasmic reticulum maintenance during interphase and in their reassembly at the end of mitosis. The complex formed with VCP has membrane fusion activity; membrane fusion activity requires USO1-GOLGA2 tethering and BET1L. VCPIP1 is also required, but not its deubiquitinating activity. Together with NSFL1C/p47, regulates the centrosomal levels of kinase AURKA/Aurora A during mitotic progression by promoting AURKA removal from centrosomes in prophase. Also, regulates spindle orientation during mitosis.