endoplasmic reticulum membrane
Peptide-N(4)-(N-acetyl-beta-glucosaminyl)asparagine amidase (NGLY1, aka PNGase) is a cytosolic peptide:N-glycanase which acts on N-glycoproteins generating free, unconjugated N-glycans and deglycosylated peptides in which the N-glycosylated asparagine residues are converted to aspartates. It is involved in the quality control system for misfolded glycoproteins exported to the cytosol that need to be targeted for degradation (Suzuki et al. 2016). NGLY1 is part of a complex that couples retrotranslocation, ubiquitination and deglycosylation. It is probably composed of NGLY1, UBX domain-containing protein 1 (UBXN1 aka SAKS1), E3 ubiquitin-protein ligase (AMFR), transitional endoplasmic reticulum ATPase (VCP), derlin-1 (DERL1), 26S protease regulatory subunit 4 (PSMC1) and UV excision repair protein RAD23 homolog B (RAD23B). NGLY1 interacts with the proteasome components RAD23B and PSMC1, directly with VCP and with DERL1, bringing it close to the endoplasmic reticulum membrane (Katiyar & Lennarz 2004, Song et al. 2005, McNeill et al. 2004, Ye et al. 2004, Katiyar et al. 2005).