Docking of HIV-1 Vpr to the nuclear envelope is mediated by the interaction with the nucleoporin hCG1.
The HIV-1 genome contains several genes coding for auxiliary proteins, including the small Vpr protein. Vpr affects the integrity of the nuclear envelope and participates in the nuclear translocation of the preintegration complex containing the viral DNA. Here, we show by photobleaching experiments performed on living cells expressing a Vpr-green fluorescent protein fusion that the protein shuttles between the nucleus and the cytoplasm, but a significant fraction is concentrated at the nuclear envelope, supporting the hypothesis that Vpr interacts with components of the nuclear pore complex. An interaction between HIV-1 Vpr and the human nucleoporin CG1 (hCG1) was revealed in the yeast two-hybrid system, and then confirmed both in vitro and in transfected cells. This interaction does not involve the FG repeat domain of hCG1 but rather the N-terminal region of the protein. Using a nuclear import assay based on digitonin-permeabilized cells, we demonstrate that hCG1 participates in the docking of Vpr at the nuclear envelope. This association of Vpr with a component of the nuclear pore complex may contribute to the disruption of the nuclear envelope and to the nuclear import of the viral DNA.
Le Rouzic
Erwann
E
Institut Cochin, Department of Infectious Diseases, CNRS UMR8104, INSERM U567, Université Paris 5, Paris, France.
Mousnier
Aurélie
A
Rustum
Cecilia
C
Stutz
Françoise
F
Hallberg
Einar
E
Dargemont
Catherine
C
Benichou
Serge
S
D021581:Active Transport, Cell Nucleus / Q000502:physiology; D036681:Fluorescence Recovery After Photobleaching; D016336:Gene Products, vpr / Q000235:genetics / Q000378:metabolism*; D017930:Genes, Reporter; D016259:Genes, myc; D049452:Green Fluorescent Proteins; D015497:HIV-1 / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D008164:Luminescent Proteins / Q000235:genetics / Q000378:metabolism; D009685:Nuclear Envelope / Q000378:metabolism*; D028861:Nuclear Pore Complex Proteins / Q000378:metabolism*; D009687:Nuclear Proteins / Q000378:metabolism*; D029543:Nucleocytoplasmic Transport Proteins; D011485:Protein Binding; D017433:Protein Structure, Secondary; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D020798:Two-Hybrid System Techniques; D054325:vpr Gene Products, Human Immunodeficiency Virus
D016336:Gene Products, vpr; D008164:Luminescent Proteins; C119720:NUP42 protein, human; D028861:Nuclear Pore Complex Proteins; D009687:Nuclear Proteins; D029543:Nucleocytoplasmic Transport Proteins; D011993:Recombinant Fusion Proteins; D054325:vpr Gene Products, Human Immunodeficiency Virus; D049452:Green Fluorescent Proteins