VCP unfolds proteins to provide unstructured regions that can enter the proteasome (inferred from the yeast homolog CDC48 in Olszewski et al. 2019). The light ribosome-associated quality control complex (light RQC complex, LTN1:NEMF:TCF25:VCP hexamer, which is homologous to RKR1(LTN1):RQC2:RQC1:CDC48 hexamer in yeast) associates with both the ubiquitinated nascent peptide and the proteasome (inferred from yeast homologs in Defenouillère et al. 2017), thus the light RQC complex appears to guide the ubiquitinated nascent peptide to the proteasome for degradation. The K48-polyubiquitinated nascent peptide is then proteolytically degraded by the 26S proteasome. During the process the PSMD2, ADRM1, and PSMD4 subunits of the 26S proteasome complex bind K48-linked polyubiquitin conjugated to the substrate protein (reviewed in Bard et al. 2018). The PSMD14 subunit of the 26S proteasome deubiquitinates the substrate protein, and the ATP-driven motor activity of the 26S proteasome feeds the substrate protein into the central pore of the proteasome, where the substrate protein is degraded (reviewed in Bard et al. 2018).