SEL1L nucleates a protein complex required for dislocation of misfolded glycoproteins.
Membrane and secretory proteins that fail to pass quality control in the endoplasmic reticulum are discharged into the cytosol and degraded by the proteasome. Many of the mammalian components involved in this process remain to be identified. We performed a biochemical search for proteins that interact with SEL1L, a protein that is part of the mammalian HRD1 ligase complex and involved in substrate recognition. SEL1L is crucial for dislocation of Class I major histocompatibility complex heavy chains by the human cytomegalovirus US11 protein. We identified AUP1, UBXD8, UBC6e, and OS9 as functionally important components of this degradation complex in mammalian cells, as confirmed by mutagenesis and dominant negative versions of these proteins.
Mueller
Britta
B
Whitehead Institute for Biomedical Research, 9 Cambridge Center, Cambridge, MA 02142, USA.
Klemm
Elizabeth J
EJ
Spooner
Eric
E
Claessen
Jasper H
JH
Ploegh
Hidde L
HL
D000818:Animals; D002352:Carrier Proteins; D002460:Cell Line; D006023:Glycoproteins / Q000378:metabolism*; D006801:Humans; D008565:Membrane Proteins; D051379:Mice; D046912:Multiprotein Complexes / Q000737:chemistry* / Q000502:physiology; D017510:Protein Folding; D011506:Proteins / Q000378:metabolism* / Q000502:physiology; D014161:Transduction, Genetic
C464942:AUP1 protein, human; D002352:Carrier Proteins; D006023:Glycoproteins; D008565:Membrane Proteins; D046912:Multiprotein Complexes; D011506:Proteins; C117384:SEL1L protein, human