title: The VCP/p97 and YOD1 Proteins Have Different Substrate-dependent Activities in Endoplasmic Reticulum-associated Degradation (ERAD).
abstract: Endoplasmic reticulum-associated degradation (ERAD) is an essential quality control mechanism of the folding state of proteins in the secretory pathway that targets unfolded/misfolded polypeptides for proteasomal degradation. The cytosolic p97/valosin-containing protein is an essential ATPase for degradation of ERAD substrates. It has been considered necessary during retro-translocation to extract proteins from the endoplasmic reticulum that are otherwise supposed to accumulate in the endoplasmic reticulum lumen. The activity of the p97-associated deubiquitinylase YOD1 is also required for substrate disposal. We used the in vivo biotinylation retro-translocation assay in mammalian cells under conditions of impaired p97 or YOD1 activity to directly discriminate their requirements and diverse functions in ERAD. Using different ERAD substrates, we found that both proteins participate in two distinct retro-translocation steps. For CD4 and MHC-Iα, which are induced to degradation by the HIV-1 protein Vpu and by the CMV immunoevasins US2 and US11, respectively, p97 and YOD1 have a retro-translocation-triggering role. In contrast, for three other spontaneous ERAD model substrates (NS1, NHK-α1AT, and BST-2/Tetherin), p97 and YOD1 are required in the downstream events of substrate deglycosylation and proteasomal degradation.
authors.affiliation: International Centre for Genetic Engineering and Biotechnology, Padriciano 99, 34149 Trieste, Italy.
authors.forename: Linda
authors.initials: L
authors.lastname: Sasset
authors.affiliation: CIBIO, University of Trento, Via delle Regole 101, 38123 Mattarello, Italy. Electronic address: gianluca.petris@unitn.it.
authors.forename: Gianluca
authors.initials: G
authors.lastname: Petris
authors.affiliation: International Centre for Genetic Engineering and Biotechnology, Padriciano 99, 34149 Trieste, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Cesaratto
authors.affiliation: International Centre for Genetic Engineering and Biotechnology, Padriciano 99, 34149 Trieste, Italy.
authors.forename: Oscar R
authors.initials: OR
authors.lastname: Burrone
mesh_terms: D000251:Adenosine Triphosphatases / Q000378:metabolism*; D015704:CD4 Antigens / Q000378:metabolism; D018797:Cell Cycle Proteins / Q000378:metabolism*; D010450:Endopeptidases / Q000378:metabolism*; D060746:Endoplasmic Reticulum-Associated Degradation; D057809:HEK293 Cells; D006801:Humans; D021381:Protein Transport; D013869:Thiolester Hydrolases / Q000378:metabolism*; D000074405:Valosin Containing Protein
chemical_list: D015704:CD4 Antigens; D018797:Cell Cycle Proteins; C545663:YOD1 protein, human; D013869:Thiolester Hydrolases; D010450:Endopeptidases; D000251:Adenosine Triphosphatases; C000614178:VCP protein, human; D000074405:Valosin Containing Protein
keywords: ATPases associated with diverse cellular activities (AAA); BirA; NHK-α1AT; NS-κLC; VCP/p97; YOD1; biotin; deubiquitylation (deubiquitination); endoplasmic reticulum-associated protein degradation (ERAD); protein degradation