Definition of the interacting interfaces of Apobec3G and HIV-1 Vif using MAPPIT mutagenesis analysis.
The host restriction factor Apobec3G is a cytidine deaminase that incorporates into HIV-1 virions and interferes with viral replication. The HIV-1 accessory protein Vif subverts Apobec3G by targeting it for proteasomal degradation. We propose a model in which Apobec3G N-terminal domains symmetrically interact via a head-to-head interface containing residues 122 RLYYFW 127. To validate this model and to characterize the Apobec3G-Apobec3G and the Apobec3G-Vif interactions, the mammalian protein-protein interaction trap two-hybrid technique was used. Mutations in the head-to-head interface abrogate the Apobec3G-Apobec3G interaction. All mutations that inhibit Apobec3G-Apobec3G binding also inhibit the Apobec3G-Vif interaction, indicating that the head-to head interface plays an important role in the interaction with Vif. Only the D128K, P129A and T32Q mutations specifically affect the Apobec3G-Vif association. In our model, D128, P129 and T32 cluster at the edge of the head-to-head interface, possibly forming a Vif binding site composed of two Apobec3G molecules. We propose that Vif either binds at the Apobec3G head-to-head interface or associates with an RNA-stabilized Apobec3G oligomer.
Lavens
Delphine
D
Department of Medical Protein Research, VIB, Department of Biochemistry, Ghent University, A. Baertsoenkaai 3, 9000 Ghent.
Peelman
Frank
F
Van der Heyden
José
J
Uyttendaele
Isabel
I
Catteeuw
Dominiek
D
Verhee
Annick
A
Van Schoubroeck
Bertrand
B
Kurth
Julia
J
Hallenberger
Sabine
S
Clayton
Reginald
R
Tavernier
Jan
J
D000071480:APOBEC-3G Deaminase; D001665:Binding Sites; D002460:Cell Line; D003564:Cytidine Deaminase / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D043525:Cytosine Deaminase / Q000737:chemistry; D019281:Dimerization; D006801:Humans; D008958:Models, Molecular; D016297:Mutagenesis, Site-Directed; D054730:Protein Interaction Domains and Motifs; D040681:Structural Homology, Protein; D020798:Two-Hybrid System Techniques; D054320:vif Gene Products, Human Immunodeficiency Virus / Q000737:chemistry* / Q000378:metabolism
D054320:vif Gene Products, Human Immunodeficiency Virus; C514847:vif protein, Human immunodeficiency virus 1; C492906:APOBEC3F protein, human; D043525:Cytosine Deaminase; D000071480:APOBEC-3G Deaminase; C464924:APOBEC3G protein, human; D003564:Cytidine Deaminase