Capturing cargo and formation of prebudding complex

Stable Identifier
R-HSA-983426
Type
Reaction [binding]
Species
Homo sapiens
Compartment
endoplasmic reticulum membrane, lumenal side of endoplasmic reticulum membrane, cytosol, endoplasmic reticulum lumen
ReviewStatus
5/5
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Capturing cargo and formation of prebudding complex
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The cytoplasmic tails of MHC class I molecules do not possess any of the known ER export sequences. BAP31 acts as a cargo receptor by exporting peptide-loaded class I MHC molecules to the ER exit sites or ER/Golgi intermediate compartment. Sec24 of the Sec23-Sec24/Sar1-GTP complex catches cargo by direct contact, forming the prebudding complex. Sar1/Sec23-Sec24 can bring about curvature of the membrane in the formation of vesicle. The cargo (antigen-bound MHC) accumulates within the COPII vesicle by binding to the Sec24 polypeptide of the COPII coat.

SARS-CoV-2 ORF8 (8) induces BECN1-dependent autophagy to degrade class I MHC leading to impaired antigen presentation (Zhang Y et al. 2021).

Literature References
PubMed ID Title Journal Year
10825291 COPI-coated ER-to-Golgi transport complexes segregate from COPII in close proximity to ER exit sites

Paccaud, JP, Lin-Marq, N, Stephens, DJ, Pagano, A, Pepperkok, R

J Cell Sci 2000
11163199 Selective export of MHC class I molecules from the ER after their dissociation from TAP

Manley, H, Spiliotis, ET, Edidin, M, Zúñiga, MC, Osorio, M

Immunity 2000
10982397 Dynamics of transitional endoplasmic reticulum sites in vertebrate cells

Glick, BS, Hammond, AT

Mol Biol Cell 2000
Participants
Input
Output
Participates
as an event of
This event is regulated
Negatively by
Regulator
8:class I MHC:BECN1 complex [endoplasmic reticulum membrane] (Homo sapiens)
Active Unit
8 homodimer [endoplasmic reticulum lumen]
Authored
Garapati, P V  (2010-10-29)
Reviewed
Elliott, T  (2011-02-11)
Messina, F  (2022-02-18)
Created
Garapati, P V  (2010-11-01)
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