Involved in spindle disassembly, degradation of ubiquitinated proteins and protein export from the endoplasmic reticulum to the cytoplasm. Acts as a chaperone that collects ubiquitinated substrates. Has a role in the endoplasmic reticulum-associated degradation (ERAD) pathway. Component of the ribosome quality control complex (RQC), a ribosome-associated complex that mediates ubiquitination and extraction of incompletely synthesized nascent chains for proteasomal degradation. CDC48 may provide the mechanical force that dislodges the polyubiquitinated nascent peptides from the exit channel. Component of the ribosome quality control complex (RQC), composed of the E3 ubiquitin ligase LTN1, RQC1 and RQC2, as well as CDC48 and its ubiquitin-binding cofactors. RQC forms a stable complex with 60S ribosomal subunits. Expressed in late sporogonial stages. Belongs to the AAA ATPase family.