HIV-1 Nef hijacks clathrin coats by stabilizing AP-1:Arf1 polygons.
The lentiviruses HIV and simian immunodeficiency virus (SIV) subvert intracellular membrane traffic as part of their replication cycle. The lentiviral Nef protein helps viruses evade innate and adaptive immune defenses by hijacking the adaptor protein 1 (AP-1) and AP-2 clathrin adaptors. We found that HIV-1 Nef and the guanosine triphosphatase Arf1 induced trimerization and activation of AP-1. Here we report the cryo-electron microscopy structures of the Nef- and Arf1-bound AP-1 trimer in the active and inactive states. A central nucleus of three Arf1 molecules organizes the trimers. We combined the open trimer with a known dimer structure and thus predicted a hexagonal assembly with inner and outer faces that bind the membranes and clathrin, respectively. Hexagons were directly visualized and the model validated by reconstituting clathrin cage assembly. Arf1 and Nef thus play interconnected roles in allosteric activation, cargo recruitment, and coat assembly, revealing an unexpectedly intricate organization of the inner AP-1 layer of the clathrin coat.
Department of Molecular and Cell Biology and California Institute for Quantitative Biosciences, University of California, Berkeley, Berkeley, CA 94720, USA.
Qing-Tao
QT
Shen
Department of Molecular and Cell Biology and California Institute for Quantitative Biosciences, University of California, Berkeley, Berkeley, CA 94720, USA.
Xuefeng
X
Ren
Life Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.
Rui
R
Zhang
Department of Molecular and Cell Biology and California Institute for Quantitative Biosciences, University of California, Berkeley, Berkeley, CA 94720, USA.
Il-Hyung
IH
Lee
Department of Molecular and Cell Biology and California Institute for Quantitative Biosciences, University of California, Berkeley, Berkeley, CA 94720, USA. Life Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA. jimhurley@berkeley.edu.
James H
JH
Hurley
D020823:ADP-Ribosylation Factor 1 / Q000737:chemistry*; D033961:Adaptor Protein Complex 1 / Q000737:chemistry*; D015703:Antigens, CD / Q000737:chemistry*; D002966:Clathrin / Q000737:chemistry / Q000648:ultrastructure; D022163:Clathrin-Coated Vesicles / Q000378:metabolism*; D020285:Cryoelectron Microscopy; D018360:Crystallography, X-Ray; D031541:Fluorescence Resonance Energy Transfer; D058851:GPI-Linked Proteins / Q000737:chemistry; D006801:Humans; D011487:Protein Conformation; D055503:Protein Multimerization; D055550:Protein Stability; D054311:nef Gene Products, Human Immunodeficiency Virus / Q000737:chemistry* / Q000648:ultrastructure; D021601:trans-Golgi Network / Q000378:metabolism; D000074010:Bone Marrow Stromal Antigen 2
D020823:ADP-Ribosylation Factor 1; D033961:Adaptor Protein Complex 1; D015703:Antigens, CD; D002966:Clathrin; D058851:GPI-Linked Proteins; D054311:nef Gene Products, Human Immunodeficiency Virus; C094572:BST2 protein, human; D000074010:Bone Marrow Stromal Antigen 2; C514837:nef protein, Human immunodeficiency virus 1