8D4D

gamma-Arf1 mediated dimeric assembly of AP-1, Arf1, Nef complex within lattice on MHC-I lipopeptide incorporated narrow membrane tubes

This is a non-PDB format compatible entry.

Summary for 8D4D

• Entry DOI: 10.2210/pdb8d4d/pdb
• EMDB information: 26853 27182
• Descriptor: ADP-ribosylation factor 1, Protein Nef, HLA class I histocompatibility antigen, A alpha chain, ... (9 entities in total)
• Functional Keywords: nef, ap, trafficking, protein transport
• Biological source: Homo sapiens (human); More
• Total number of polymer chains: 18
• Total formula weight: 669132.30

Authors

Hooy, R.M.,Hurley, J.H. (deposition date: 2022-06-01, release date: 2023-06-14, Last modification date: 2024-06-12)

Primary citation

Hooy, R.M.,Iwamoto, Y.,Tudorica, D.A.,Ren, X.,Hurley, J.H.
Self-assembly and structure of a clathrin-independent AP-1:Arf1 tubular membrane coat.
Sci Adv, 8:eadd3914-eadd3914, 2022

PubMed Abstract: The adaptor protein (AP) complexes not only form the inner layer of clathrin coats but also have clathrin-independent roles in membrane traffic whose mechanisms are unknown. HIV-1 Nef hijacks AP-1 to sequester major histocompatibility complex class I (MHC-I), evading immune detection. We found that AP-1:Arf1:Nef:MHC-I forms a coat on tubulated membranes without clathrin and determined its structure. The coat assembles via Arf1 dimer interfaces. AP-1-positive tubules are enriched in cells upon clathrin knockdown. Nef localizes preferentially to AP-1 tubules in cells, explaining how Nef sequesters MHC-I. Coat contact residues are conserved across Arf isoforms and the Arf-dependent AP complexes AP-1, AP-3, and AP-4. Thus, AP complexes can self-assemble with Arf1 into tubular coats without clathrin or other scaffolding factors. The AP-1:Arf1 coat defines the structural basis of a broader class of tubulovesicular membrane coats as an intermediate in clathrin vesicle formation from internal membranes and as an MHC-I sequestration mechanism in HIV-1 infection.

PubMed: 36269825
DOI: 10.1126/sciadv.add3914

Experimental method

ELECTRON MICROSCOPY (9.6 Å)