Involved in CDC48-dependent protein degradation through the ubiquitin/proteasome pathway. Direct or indirect positive regulator of GLC7 activity. Forms a complex composed of CDC48, NPL4, UFD1, DOA1, SHP1 and deubiquitinase OTU1 (PubMed:16427015). Interacts with CDC48 (PubMed:15258615). Present with 3200 molecules/cell in log phase SD medium.