Analysis of HIV-1 Viral Infectivity Factor-mediated Proteasome-dependent Depletion of APOBEC3G

Abstract

To study how HIV-1 viral infectivity factor (Vif) mediates proteasome-dependent depletion of host factor APOBEC3G, functional and nonfunctional Vif-APOBEC3G interactions were correlated with subcellular localization. APOBEC3G localized throughout the cytoplasm and co-localized with γ-tubulin, 20 S proteasome subunit, and ubiquitin at punctate cytoplasmic bodies that can be used to monitor the Vif-APOBEC3G interaction in the cell. Through immunostaining and live imaging, we showed that a substantial fraction of Vif localized to the nucleus, and this localization was impaired by deletion of amino acids 12-23. When co-expressed, Vif exhibited more pronounced localization to the cytoplasm and reduced the total cellular levels of APOBEC3G but rarely co-localized with APOBEC3G at cytoplasmic bodies. On the contrary, VifC114S, which is inactive but continues to interact with APOBEC3G, stably associated with APOBEC3G in the cytoplasm, resulting in complete co-localization at cytoplasmic bodies and a dose-dependent exclusion of VifC114S from the nucleus. Following proteasome inhibition, cytoplasmic APOBEC3G levels increased, and both proteins co-accumulated nonspecifically into a vimentin-encaged aggresome. Furthermore in the presence or absence of APOBEC3G, Vif localization was significantly altered by proteasome inhibition, suggesting that aberrant localization may also contribute to the loss of Vif function. Finally mutations at Vif Ile9 disrupted the ability of Vif or VifC114S to coimmunoprecipitate and to co-localize with APOBEC3G, suggesting that the N terminus of Vif mediates interactions with APOBEC3G. Taken together, these results demonstrate that cytoplasmic Vif-APOBEC3G interactions are required but are not sufficient for Vif to modulate APOBEC3G and can be monitored by co-localization in vivo. To study how HIV-1 viral infectivity factor (Vif) mediates proteasome-dependent depletion of host factor APOBEC3G, functional and nonfunctional Vif-APOBEC3G interactions were correlated with subcellular localization. APOBEC3G localized throughout the cytoplasm and co-localized with γ-tubulin, 20 S proteasome subunit, and ubiquitin at punctate cytoplasmic bodies that can be used to monitor the Vif-APOBEC3G interaction in the cell. Through immunostaining and live imaging, we showed that a substantial fraction of Vif localized to the nucleus, and this localization was impaired by deletion of amino acids 12-23. When co-expressed, Vif exhibited more pronounced localization to the cytoplasm and reduced the total cellular levels of APOBEC3G but rarely co-localized with APOBEC3G at cytoplasmic bodies. On the contrary, VifC114S, which is inactive but continues to interact with APOBEC3G, stably associated with APOBEC3G in the cytoplasm, resulting in complete co-localization at cytoplasmic bodies and a dose-dependent exclusion of VifC114S from the nucleus. Following proteasome inhibition, cytoplasmic APOBEC3G levels increased, and both proteins co-accumulated nonspecifically into a vimentin-encaged aggresome. Furthermore in the presence or absence of APOBEC3G, Vif localization was significantly altered by proteasome inhibition, suggesting that aberrant localization may also contribute to the loss of Vif function. Finally mutations at Vif Ile9 disrupted the ability of Vif or VifC114S to coimmunoprecipitate and to co-localize with APOBEC3G, suggesting that the N terminus of Vif mediates interactions with APOBEC3G. Taken together, these results demonstrate that cytoplasmic Vif-APOBEC3G interactions are required but are not sufficient for Vif to modulate APOBEC3G and can be monitored by co-localization in vivo. HIV-1 1The abbreviations used are: HIV-1, human immunodeficiency virus, type 1; YFP, yellow fluorescent protein; CFP, cyan fluorescent protein; RFP, red fluorescent protein; GFP, green fluorescent protein; Vif, viral infectivity factor; HA, hemagglutinin; ALLN, N-acetyl-Leu-Leu-norleucine-CHO; PBS, phosphate-buffered saline; mAb, monoclonal antibody; α-, anti-; BSA, bovine serum albumin; APO, APOBEC3G. infectivity is dependent on viral infectivity factor (Vif), a multifunctional RNA-binding protein (for a review, see Ref. 1Rose K.M. Marin M. Kozak S.L. Kabat D. Trends Mol. Med. 2004; 10: 291-297Abstract Full Text Full Text PDF PubMed Scopus (47) Google Scholar). During vif-deficient HIV-1 infection, host cellular factor APOBEC3G is packaged into virions (2Sheehy A.M. Gaddis N.C. Choi J.D. Malim M.H. Nature. 2002; 418: 646-650Crossref PubMed Scopus (1914) Google Scholar, 3Harris R.S. Bishop K.N. Sheehy A.M. Craig H.M. Petersen-Mahrt S.K. Watt I.N. Neuberger M.S. Malim M.H. Cell. 2003; 113: 803-809Abstract Full Text Full Text PDF PubMed Scopus (1144) Google Scholar, 4Lecossier D. Bouchonnet F. Clavel F. Hance A.J. Science. 2003; 300: 1112Crossref PubMed Scopus (588) Google Scholar, 5Mariani R. Chen D. Schrofelbauer B. Navarro F. Konig R. Bollman B. Munk C. Nymark-McMahon H. Landau N.R. Cell. 2003; 114: 21-31Abstract Full Text Full Text PDF PubMed Scopus (771) Google Scholar, 6Zhang H. Yang B. Pomerantz R.J. Zhang C. Arunachalam S.C. Gao L. Nature. 2003; 424: 94-98Crossref PubMed Scopus (919) Google Scholar) through an interaction with HIV-1 Gag (7Douaisi M. Dussart S. Courcoul M. Bessou G. Vigne R. Decroly E. Biochem. Biophys. Res. Commun. 2004; 321: 566-573Crossref PubMed Scopus (87) Google Scholar, 8Alce T.M. Popik W. J. Biol. Chem. 2004; 279: 34083-34086Abstract Full Text Full Text PDF PubMed Scopus (204) Google Scholar, 9Cen S. Guo F. Niu M. Saadatmand J. Deflassieux J. Kleiman L. J. Biol. Chem. 2004; 279: 33177-33184Abstract Full Text Full Text PDF PubMed Scopus (220) Google Scholar, 10Svarovskaia E.S. Xu H. Mbisa J.L. Barr R. Gorelick R.J. Ono A. Freed E.O. Hu W.S. Pathak V.K. J. Biol. Chem. 2004; 279: 35822-35828Abstract Full Text Full Text PDF PubMed Scopus (231) Google Scholar) and hypermutates the viral minus strand of the first cDNA strand synthesized during HIV-1 reverse transcription (3Harris R.S. Bishop K.N. Sheehy A.M. Craig H.M. Petersen-Mahrt S.K. Watt I.N. Neuberger M.S. Malim M.H. Cell. 2003; 113: 803-809Abstract Full Text Full Text PDF PubMed Scopus (1144) Google Scholar, 4Lecossier D. Bouchonnet F. Clavel F. Hance A.J. Science. 2003; 300: 1112Crossref PubMed Scopus (588) Google Scholar, 5Mariani R. Chen D. Schrofelbauer B. Navarro F. Konig R. Bollman B. Munk C. Nymark-McMahon H. Landau N.R. Cell. 2003; 114: 21-31Abstract Full Text Full Text PDF PubMed Scopus (771) Google Scholar, 6Zhang H. Yang B. Pomerantz R.J. Zhang C. Arunachalam S.C. Gao L. Nature. 2003; 424: 94-98Crossref PubMed Scopus (919) Google Scholar, 11Mangeat B. Turelli P. Caron G. Friedli M. Perrin L. Trono D. Nature. 2003; 424: 99-103Crossref PubMed Scopus (1248) Google Scholar, 12Goff S.P. Cell. 2003; 114: 281-283Abstract Full Text Full Text PDF PubMed Scopus (60) Google Scholar, 13Gu Y. Sundquist W.I. Nature. 2003; 424: 21-22Crossref PubMed Scopus (34) Google Scholar, 14Yu Q. Konig R. Pillai S. Chiles K. Kearney M. Palmer S. Richman D. Coffin J.M. Landau N.R. Nat. Struct. Mol. Biol. 2004; 11: 435-442Crossref PubMed Scopus (506) Google Scholar). APOBEC3G cytidine deaminase activity increases the frequency of dU in the HIV-1 genome, which leads to genome degradation, incomplete cDNA synthesis, and a detrimentally high mutation rate within the HIV-1 genome (5Mariani R. Chen D. Schrofelbauer B. Navarro F. Konig R. Bollman B. Munk C. Nymark-McMahon H. Landau N.R. Cell. 2003; 114: 21-31Abstract Full Text Full Text PDF PubMed Scopus (771) Google Scholar, 11Mangeat B. Turelli P. Caron G. Friedli M. Perrin L. Trono D. Nature. 2003; 424: 99-103Crossref PubMed Scopus (1248) Google Scholar, 12Goff S.P. Cell. 2003; 114: 281-283Abstract Full Text Full Text PDF PubMed Scopus (60) Google Scholar, 13Gu Y. Sundquist W.I. Nature. 2003; 424: 21-22Crossref PubMed Scopus (34) Google Scholar, 15Harris R.S. Petersen-Mahrt S.K. Neuberger M.S. Mol. Cell. 2002; 10: 1247-1253Abstract Full Text Full Text PDF PubMed Scopus (455) Google Scholar, 16Klarmann G.J. Chen X. North T.W. Preston B.D. J. Biol. Chem. 2003; 278: 7902-7909Abstract Full Text Full Text PDF PubMed Scopus (71) Google Scholar). In the presence of Vif, intracellular APOBEC3G protein levels decrease, and consequently less APOBEC3G is packaged (17Stopak K. de Noronha C. Yonemoto W. Greene W.C. Mol. Cell. 2003; 12: 591-601Abstract Full Text Full Text PDF PubMed Scopus (603) Google Scholar, 18Kao S. Akari H. Khan M.A. Dettenhofer M. Yu X.F. Strebel K. J. Virol. 2003; 77: 1131-1140Crossref PubMed Scopus (56) Google Scholar, 19Marin M. Rose K.M. Kozak S.L. Kabat D. Nat. Med. 2003; 9: 1398-1403Crossref PubMed Scopus (683) Google Scholar, 20Sheehy A.M. Gaddis N.C. Malim M.H. Nat. Med. 2003; 9: 1404-1407Crossref PubMed Scopus (809) Google Scholar, 21Yu X. Yu Y. Liu B. Luo K. Kong W. Mao P. Yu X.F. Science. 2003; 302: 1056-1060Crossref PubMed Scopus (1002) Google Scholar, 22Liu B. Yu X. Luo K. Yu Y. Yu X.F. J. Virol. 2004; 78: 2072-2081Crossref PubMed Scopus (131) Google Scholar), increasing the of HIV-1 to for how Vif APOBEC3G that Vif APOBEC3G by APOBEC3G to the proteasome (17Stopak K. de Noronha C. Yonemoto W. Greene W.C. Mol. Cell. 2003; 12: 591-601Abstract Full Text Full Text PDF PubMed Scopus (603) Google Scholar, 19Marin M. Rose K.M. Kozak S.L. Kabat D. Nat. Med. 2003; 9: 1398-1403Crossref PubMed Scopus (683) Google Scholar, 20Sheehy A.M. Gaddis N.C. Malim M.H. Nat. Med. 2003; 9: 1404-1407Crossref PubMed Scopus (809) Google Scholar, 21Yu X. Yu Y. Liu B. Luo K. Kong W. Mao P. Yu X.F. Science. 2003; 302: 1056-1060Crossref PubMed Scopus (1002) Google Scholar, 22Liu B. Yu X. Luo K. Yu Y. Yu X.F. J. Virol. 2004; 78: 2072-2081Crossref PubMed Scopus (131) Google Scholar, A. B. P. Zhang C. M. D. J. Biol. Chem. 2004; 279: Full Text Full Text PDF PubMed Scopus Google Scholar, R.S. Neuberger M.S. Biol. 2003; Full Text Full Text PDF PubMed Scopus Google Scholar) through a X. Yu Y. Liu B. Luo K. Kong W. Mao P. Yu X.F. Science. 2003; 302: 1056-1060Crossref PubMed Scopus (1002) Google Scholar). Vif to modulate APOBEC3G levels through (17Stopak K. de Noronha C. Yonemoto W. Greene W.C. Mol. Cell. 2003; 12: 591-601Abstract Full Text Full Text PDF PubMed Scopus (603) Google Scholar). Vif and APOBEC3G coimmunoprecipitate from human and APOBEC3G and Vif to interact in (5Mariani R. Chen D. Schrofelbauer B. Navarro F. Konig R. Bollman B. Munk C. Nymark-McMahon H. Landau N.R. Cell. 2003; 114: 21-31Abstract Full Text Full Text PDF PubMed Scopus (771) Google Scholar, K. de Noronha C. Yonemoto W. Greene W.C. Mol. Cell. 2003; 12: 591-601Abstract Full Text Full Text PDF PubMed Scopus (603) Google Scholar, 19Marin M. Rose K.M. Kozak S.L. Kabat D. Nat. Med. 2003; 9: 1398-1403Crossref PubMed Scopus (683) Google Scholar, 21Yu X. Yu Y. Liu B. Luo K. Kong W. Mao P. Yu X.F. Science. 2003; 302: 1056-1060Crossref PubMed Scopus (1002) Google Scholar, A. B. P. Zhang C. M. D. J. Biol. Chem. 2004; 279: Full Text Full Text PDF PubMed Scopus Google Scholar, R.S. Neuberger M.S. Biol. 2003; Full Text Full Text PDF PubMed Scopus Google Scholar, B. Turelli P. S. Trono D. J. Biol. Chem. 2004; 279: Full Text Full Text PDF PubMed Scopus Google Scholar), suggesting that these proteins In of the required for Vif-APOBEC3G functional Vif the can coimmunoprecipitate with APOBEC3G but are not functional M. Rose K.M. Kozak S.L. Kabat D. Nat. Med. 2003; 9: 1398-1403Crossref PubMed Scopus (683) Google Scholar, Sheehy A.M. Malim M.H. J. Virol. PubMed Google Scholar). at or that Vif also Vif inactive APOBEC3G in the of S. Khan M.A. E. R. A. Strebel K. J. Virol. 2003; 77: PubMed Scopus Google Scholar), but these mutations interactions with APOBEC3G is In this we correlated proteasome-dependent of APOBEC3G with the subcellular localization of the Vif-APOBEC3G Through the of functional and nonfunctional Vif-APOBEC3G we that APOBEC3G the subcellular of Vif, that Vif-APOBEC3G interactions were required but were not sufficient for Vif to modulate APOBEC3G protein and that Vif Ile9 was for Vif to interact with APOBEC3G. HIV-1 which the and which the VifC114S were of Strebel S. Khan M.A. E. R. A. Strebel K. J. Virol. 2003; 77: PubMed Scopus Google Scholar). HIV-1 was used a for Vif and was a of of HIV-1 Vif deletion and Sheehy A.M. Malim M.H. J. Virol. PubMed Google Scholar), were of Malim through were from yellow fluorescent protein of Vif or Vif the Vif was and into the and of APOBEC3G was from cDNA from human from To the APOBEC3G was into the and of of APOBEC3G with a a Kozak was of the APOBEC3G during APOBEC3G with a and were by APOBEC3G into the and of and the and of fluorescent protein was by HIV-1 into the and of To mutations within the VifC114S was used a for and the resulting were into from was and used to and were in a at in with bovine and was into and were in or the were of used and the of for are and in the When were by the of live and were into and the were proteasome of or the of was to to or of and total protein of a or was in phosphate-buffered and in or of with and a of a for for at with were from the and was by for at in a was by protein of was to in of was by with of To were first with a of for at was from by with of an for at was by with a of for at by in of for was by for at in of protein were and reduced by by at for was by and a a Following the was in in and for in and the of were in in CFP, YFP, and were a monoclonal to was with a to was with a to was with a to Vif and Vif were a Vif was through the and of of HIV-1 Vif monoclonal from H. Malim Malim M.H. J. Virol. PubMed Google Scholar, Malim M.H. J. Virol. PubMed Google Scholar, Malim M.H. J. Virol. PubMed Google were used at a of were with the and to and were in in for 20 by with for 20 were and for were for in bovine serum and were in S proteasome and were in and with for and to or were to in and with for To was used at a of live imaging, were the were with a to a and with an and and an to and a were from a and was and of the of APOBEC3G by of depletion of APOBEC3G was a of Vif from to to of of depletion was by the levels of with Vif to the depletion by Vif was the and of levels by proteasome was at the depletion by Vif, of was at the and proteasome In the absence of Vif, levels were not significantly by proteasome at the of for which a in was were also with or in the presence and absence of Vif not In the presence or absence not of proteasome the levels of Vif and in the of of was also by In Vif, was not or was at a significantly reduced to the with levels were by proteasome inhibition, and the of the proteins of the subcellular localization of APOBEC3G in was and and were in live APOBEC3G localized throughout the cytoplasm and was from the APOBEC3G was also at punctate bodies that were in to the but were not from in the cytoplasm of that of was sufficient to the protein by live this of to to cytoplasmic bodies in of When co-expressed, and which also not co-localized to the cytoplasmic bodies of and co-localized at cytoplasmic bodies showed that Taken together, these results that cytoplasmic bodies APOBEC3G that may the functional of the protein A. A. J. J. J. 2002; PubMed Scopus Google Scholar, K. A. M. A. K. J. Biol. Chem. 2003; 278: Full Text Full Text PDF PubMed Scopus Google Scholar). bodies not co-localize with for the or not were in the of the nucleus, we also cytoplasmic bodies were associated with the In the absence of APOBEC3G, throughout the cytoplasm and in the of to a not In the presence of APOBEC3G, was at cytoplasmic bodies but not co-localize with the not be with for protein suggesting that these proteins may be of an of 20 S proteasome and ubiquitin that both proteins were associated with cytoplasmic bodies and of protein at cytoplasmic bodies was and to the bodies. bodies were also not by a of the suggesting that these were from an Trends Biol. 10: Full Text Full Text PDF PubMed Scopus Google and see of Vif in Vif was in and was localized in live with Vif localized to the in of and to the cytoplasm in of In with Vif localized to the cytoplasm in of In live a of Vif exhibited a localization more Vif were also in that exhibited more localization in of in showed a localization in and in and this was the for or Vif not To the of on by was with by immunostaining with and Following localized to the cytoplasm, and the localization or and were Following showed localized to the nucleus, but with or more to be in the cytoplasm results that the of can significantly the localization of Vif and that cytoplasmic Vif may be more to To a of Vif of a of Vif deletion and and VifC114S were of exhibited a localization to by and in and with the of which was to the cytoplasm that a of Vif to the nucleus. of the Vif-APOBEC3G in the associated with the Vif-APOBEC3G was live with a nonfunctional S. Khan M.A. E. R. A. Strebel K. J. Virol. 2003; 77: PubMed Scopus Google Scholar), VifC114S was inactive VifC114S with that the loss of associated with the mutation was not to an to interact with APOBEC3G. Vif also with levels significantly by Vif In to reduced the levels of and but not Furthermore the levels of and that with were to the levels of Vif that with which a deletion within the but not was to coimmunoprecipitate with M. Rose K.M. Kozak S.L. Kabat D. Nat. Med. 2003; 9: 1398-1403Crossref PubMed Scopus (683) Google Scholar). with this but not with results that can interact with and the depletion of APOBEC3G. that APOBEC3G, the subcellular localization of and was in live When and were at a of to a in was to with In both proteins were the was cytoplasmic bodies were rarely and co-localization in the cytoplasm was not not increasing the of the of and increasing a fraction of was to the cytoplasm from the more was in the cytoplasm, co-localization of and at cytoplasmic bodies was rarely the of more was to the cytoplasm, and was from the In to co-localized with cytoplasmic bodies the of to the of in the nucleus, but and co-localized at cytoplasmic bodies not suggesting that the of was dependent on the cellular levels of to co-localized with at cytoplasmic bodies but was not to the cytoplasm with which was with the reduced levels of that with localization of and both of which not coimmunoprecipitate with not not in the presence of and co-localization at cytoplasmic bodies was not and these results that an interaction is required for Vif and APOBEC3G to co-localize and that the frequency of Vif-APOBEC3G co-localization is by the of used the of interactions and in the of a to mutations that disrupted Vif-APOBEC3G interactions and the is by a mutation that from a in the VifC114S the localization of was not altered in the presence of and co-localization at cytoplasmic bodies was not and Furthermore not coimmunoprecipitate with the or mutation not significantly coimmunoprecipitate with and not levels in the In the presence of the localization of and was not and co-localization at cytoplasmic bodies was not and results that mutations at Vif Ile9 disrupted Vif-APOBEC3G interactions and that these interactions were for APOBEC3G to the localization of of Vif and APOBEC3G during subcellular localization of Vif, and Vif-APOBEC3G interactions were also proteasome with Vif, proteasome the levels of that the not with the of Vif through the proteasome not Following proteasome inhibition, and Vif into a vimentin-encaged In the of exhibited levels of and and a localization was for Vif with proteasome not significantly levels in of the and into a vimentin-encaged When and were into at a of Vif and was rarely in the in both proteins be Vif and exhibited localization throughout the cytoplasm to an in cytoplasmic levels and in the of both proteins and localization be proteasome in proteasome in co-localization of and Vif ALLN, or within a vimentin-encaged and also proteasome suggesting that co-localization to an not a Vif and co-localized to within the which were also protein was and Vif and not co-localization in the cytoplasm of and Vif localized in the ALLN, of of this we the Vif-APOBEC3G by Vif with the subcellular localization of Vif-APOBEC3G of Vif on APOBEC3G was to be to the levels of Vif and APOBEC3G in the B. Yu X. Luo K. Yu Y. Yu X.F. J. Virol. 2004; 78: 2072-2081Crossref PubMed Scopus (131) Google Scholar), and the to which Vif the of APOBEC3G a of (5Mariani R. Chen D. Schrofelbauer B. Navarro F. Konig R. Bollman B. Munk C. Nymark-McMahon H. Landau N.R. Cell. 2003; 114: 21-31Abstract Full Text Full Text PDF PubMed Scopus (771) Google Scholar, S. Khan M.A. E. R. A. Strebel K. J. Virol. 2003; 77: PubMed Scopus Google Scholar). that the ability to both the depletion of APOBEC3G by Vif and the of APOBEC3G proteasome on the of APOBEC3G at the the of was which also to the of proteasome a on APOBEC3G in the absence of proteasome an of on the M.H. A. 2002; PubMed Scopus Google Scholar), of which is a in P. M. J. G. G.J. Mol. Biol. Cell. 12: PubMed Scopus Google Scholar, A. J. Biol. Chem. Full Text Full Text PDF PubMed Scopus Google Scholar), this in APOBEC3G levels of are used may be to the proteasome on Taken together, these results that can be used to study the Vif and APOBEC3G but the levels of is for the of Vif on APOBEC3G. of throughout the cytoplasm in which is with the of APOBEC3G and M. Rose K.M. Kozak S.L. Kabat D. Nat. Med. 2003; 9: 1398-1403Crossref PubMed Scopus (683) Google Scholar). localization also showed that APOBEC3G with and to a with ubiquitin and the 20 S proteasome at punctate cytoplasmic bodies that of or with γ-tubulin, cytoplasmic bodies were from the were not by a and were not which in to protein and proteasome (for a review, see Ref. M. G. E. J. Biol. Chem. 2004; 279: Full Text Full Text PDF PubMed Scopus Google Scholar). we that APOBEC3G in and APOBEC3G which the functional of the protein A. A. J. J. J. 2002; PubMed Scopus Google Scholar, K. A. M. A. K. J. Biol. Chem. 2003; 278: Full Text Full Text PDF PubMed Scopus Google Scholar), localized to cytoplasmic bodies. of APOBEC3G into cytoplasmic bodies a M. G. E. J. Biol. Chem. 2004; 279: Full Text Full Text PDF PubMed Scopus Google Scholar), the cytidine deaminase from the of the proteasome that the of APOBEC3G was to proteasome degradation, which may the for APOBEC3G to into cytoplasmic was also for a of A. J. Biol. Chem. Full Text Full Text PDF PubMed Scopus Google Scholar). the of these cytoplasmic bodies these bodies can an intracellular of the Vif-APOBEC3G Furthermore co-localization of APOBEC3G and the that the APOBEC3G to the HIV-1 D. M.A. G. T.M. M. J. Biol. 2002; PubMed Scopus Google Scholar). of HIV-1 live that localized to both localized to the of localization of the of Vif or and in both and and Furthermore showed that amino acids of Vif were for localization. Vif was to in the cytoplasm and was in the nucleus, which was a that was to Malim M.H. J. Virol. PubMed Google Scholar, Strebel K. J. Virol. PubMed Google Scholar, J. P. J. Virol. PubMed Google Scholar). to immunodeficiency Vif J. Virol. PubMed Scopus Google Scholar), we that with the protein not the localization of in but with to the Vif was to localization that localization was less was more to to the cytoplasm with or which that cytoplasmic Vif is more to these results that a more substantial fraction of Vif to the and are with that Vif with proteins R. Marin M. Kozak S.L. Kabat D. J. Virol. 2002; PubMed Scopus Google Scholar) and F. A. J. W. C. P. J. Virol. 2004; 78: PubMed Scopus Google Scholar). Vif with of Vif-APOBEC3G that inactive VifC114S with APOBEC3G but not function. the is required for but not for Vif-APOBEC3G which was and by M. Rose K.M. Kozak S.L. Kabat D. Nat. Med. 2003; 9: 1398-1403Crossref PubMed Scopus (683) Google Scholar, 21Yu X. Yu Y. Liu B. Luo K. Kong W. Mao P. Yu X.F. Science. 2003; 302: 1056-1060Crossref PubMed Scopus (1002) Google Scholar, 22Liu B. Yu X. Luo K. Yu Y. Yu X.F. J. Virol. 2004; 78: 2072-2081Crossref PubMed Scopus (131) Google Scholar, A. B. P. Zhang C. M. D. J. Biol. Chem. 2004; 279: Full Text Full Text PDF PubMed Scopus Google Scholar). of these that interactions with APOBEC3G were not sufficient for Vif to APOBEC3G and that a was through Vif and APOBEC3G Vif is a for proteasome in the absence of APOBEC3G study and Ref. H. M. S. Khan M.A. M. A. Strebel K. J. Biol. Chem. 2004; 279: Full Text Full Text PDF PubMed Scopus Google Scholar), an for Vif is that a interaction with APOBEC3G leads to the of both this type of A. B. P. Zhang C. M. D. J. Biol. Chem. 2004; 279: Full Text Full Text PDF PubMed Scopus Google Scholar, H. M. S. Khan M.A. M. A. Strebel K. J. Biol. Chem. 2004; 279: Full Text Full Text PDF PubMed Scopus Google Scholar). to type Vif, the levels of VifC114S were proteasome not suggesting that this was a for proteasome VifC114S with APOBEC3G and was a for proteasome but not APOBEC3G a and a for Vif an and nonfunctional Vif-APOBEC3G interactions were correlated with subcellular localization in live Vif that in depletion of APOBEC3G by Vif, of the proteins be within the and the of be by the of showed that increasing the of the of that localized to the cytoplasm, that of APOBEC3G the localization of results also that Vif and APOBEC3G in the cytoplasm and that Vif localization was by interactions with and rarely co-localized to cytoplasmic bodies more to co-localize with APOBEC3G in the both and co-localized with throughout the cytoplasm and to cytoplasmic suggesting that may Vif from to cytoplasmic bodies. In the presence of in was from the nucleus, that in the absence of Vif and APOBEC3G in the cytoplasm that Vif from to the nucleus. of and in the cytoplasm and at cytoplasmic bodies was used the for a in which we the which not interact with APOBEC3G. that mutations of Ile9 were sufficient to and co-localization with APOBEC3G, suggesting that the N terminus of Vif mediates interactions with APOBEC3G. reduced of co-localization and at cytoplasmic bodies that depletion of APOBEC3G may not be to a of the but throughout the of co-localization at cytoplasmic bodies may also the of functional Vif-APOBEC3G and Vif may the depletion of APOBEC3G APOBEC3G at cytoplasmic bodies. a loss in Vif to the of cytoplasmic we that the functional Vif-APOBEC3G interaction be by proteasome to Vif function. In the presence of Vif, a in the cytoplasmic levels of APOBEC3G was proteasome inhibition, and the proteins co-accumulated into a vimentin-encaged aggresome. both Vif and APOBEC3G into and and also into proteasome co-localization at not or from a interaction and may be an of proteasome of an is a cellular to proteasome Trends Biol. 10: Full Text Full Text PDF PubMed Scopus Google Scholar), and the of proteasome on the of the cytoplasm that co-localization and interactions these may not be of APOBEC3G, Vif levels and localization in to proteasome inhibition, and Vif was into both and cytoplasmic suggesting that Vif may be for in the nucleus, cytoplasm, or the that proteasome may to Vif through aberrant localization or these that proteasome on the localization of Vif that be into proteasome to study Vif APOBEC3G. In this the Vif-APOBEC3G and Vif Vif to the of APOBEC3G to be but of the of in this into Vif are also to Ile9 is in to APOBEC3G, but this a first the of the Vif-APOBEC3G J. Richman for in and of the R. and Strebel for and H. Malim for and also of the for