ATP-dependent chaperone which probably uses the energy provided by ATP hydrolysis to generate mechanical force to unfold substrate proteins, disassemble protein complexes, and disaggregate protein aggregates. Can also prevent aggregation of unfolded proteins also in an ATP-independent manner. Targets polyubiquitinated proteins for proteasomal degradation by binding to 'Lys-48'-linked polyubiquitin chains. Involved in the cytoplasmic elimination of misfolded proteins exported from the ER. This pathway, known as ERAD, prevents the activation of the unfolded protein response (UPR) caused by the accumulation of misfolded proteins in the ER. In association with helicase him-6 and GTPase crp-1, regulates the unfolded protein response (UPR) following ER stress, probably independently of the ERAD pathway. Together with udf-2 and chn-1, regulates myosin assembly in body wall muscles by targeting myosin chaperone unc-45 for proteasomal degradation. Together with the ufd-1-npl-4 complex, controls the switch from spermatogenesis to oogenesis by regulating E3 ligase cul-2 complex-mediated tra-1 proteasomal degradation. During oocyte meiosis and together with cdc-48.2, required for chromosome condensation at the diakinesis phase in prophase I and for progression of metaphase I. During the first embryonic cell division, regulates DNA replication and thus chromosome segregation and decondensation, and nuclear envelope re-assembly. In S phase and in association with ufd-1, npl-4.1 and/or npl-4.2 and ubxn-3, ensures the degradation of DNA licensing factor cdt-1 after the initiation of DNA replication and thus the disassembly of the DNA replication CMG helicase complex by promoting the dissociation from chromatin of several of its components including cdc-45 and sld-5. Regulates ubxn-3 nuclear localization during S phase. During the first embryonic cell divisions and together with cdc-48.2, regulates the re-assembly of the nuclear envelope after mitosis possibly by inactivating kinase air-2, a component of the chromosomal passenger complex (CPC). However, in another study, cdc-48.1 does not appear to be implicated in the regulation of air-2.
