UBX Domain Protein 2B (UBXN2B) is a 331 amino acid protein which comprises one UBX domain and one SEP domain. UBXN2B is essential for ER and Golgi biogenesis and also takes a place in their maintenance during interphase, as well as their reassembly at the end of mitosis. Through interaction with VCP, UBXN2B forms a complex that has membrane fusion activity.