title: Definition of the interacting interfaces of Apobec3G and HIV-1 Vif using MAPPIT mutagenesis analysis.
abstract: 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.
authors.affiliation: Department of Medical Protein Research, VIB, Department of Biochemistry, Ghent University, A. Baertsoenkaai 3, 9000 Ghent.
authors.forename: Delphine
authors.initials: D
authors.lastname: Lavens
authors.forename: Frank
authors.initials: F
authors.lastname: Peelman
authors.forename: José
authors.initials: J
authors.lastname: Van der Heyden
authors.forename: Isabel
authors.initials: I
authors.lastname: Uyttendaele
authors.forename: Dominiek
authors.initials: D
authors.lastname: Catteeuw
authors.forename: Annick
authors.initials: A
authors.lastname: Verhee
authors.forename: Bertrand
authors.initials: B
authors.lastname: Van Schoubroeck
authors.forename: Julia
authors.initials: J
authors.lastname: Kurth
authors.forename: Sabine
authors.initials: S
authors.lastname: Hallenberger
authors.forename: Reginald
authors.initials: R
authors.lastname: Clayton
authors.forename: Jan
authors.initials: J
authors.lastname: Tavernier
mesh_terms: 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
chemical_list: 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