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Jeremy Luban - One of the best experts on this subject based on the ideXlab platform.
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Cyclophilin A retrotrAnsposition into trim5 explAins owl monkey resistAnce to hiv 1
Nature, 2004Co-Authors: David M Sayah, Elena Sokolskaja, Lionel Berthoux, Jeremy LubanAbstract:In Old World primAtes, TRIM5-α confers A potent block to humAn immunodeficiency virus type 1 (HIV-1) infection thAt Acts After virus entry into cells1,2,3,4,5. Cyclophilin A (CypA) binding to virAl cApsid protects HIV-1 from A similAr Activity in humAn cells4,6,7,8. Among New World primAtes, only owl monkeys exhibit post-entry restriction of HIV-1 (ref. 1). PArAdoxicAlly, the bArrier to HIV-1 in owl monkey cells is releAsed by cApsid mutAnts or drugs thAt disrupt cApsid interAction with CypA4. Here we show thAt knockdown of owl monkey CypA by RNA interference (RNAi) correlAtes with suppression of Anti-HIV-1 Activity. However, reintroduction of CypA protein to RNAi-treAted cells did not restore AntivirAl Activity. A seArch for AdditionAl RNAi tArgets uneArthed TRIMCyp, An RNAi-responsive messenger RNA encoding A TRIM5–CypA fusion protein. TRIMCyp Accounts for post-entry restriction of HIV-1 in owl monkeys And blocks HIV-1 infection when trAnsferred to otherwise infectAble humAn or rAt cells. It seems thAt TRIMCyp Arose After the divergence of New And Old World primAtes when A LINE-1 retrotrAnsposon cAtAlysed the insertion of A CypA complementAry DNA into the TRIM5 locus. This is the first vertebrAte exAmple of A chimAeric gene generAted by this mechAnism of exon shuffling.
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Cyclophilin A modulAtes the sensitivity of hiv 1 to host restriction fActors
Nature Medicine, 2003Co-Authors: Greg J Towers, Jeremy Luban, Theodora Hatziioannou, Simone Cowan, Stephen P Goff, Paul D BieniaszAbstract:MAny mAmmAliAn species express restriction fActors thAt confer host resistAnce to retrovirAl infection. Here we show thAt HIV-1 sensitivity to restriction fActors is modulAted by Cyclophilin A (CypA), A host cell protein thAt binds the HIV-1 cApsid protein (CA). In certAin nonhumAn primAte cells, the CA-CypA interAction is essentiAl for restriction: HIV-1 infectivity is increAsed >100-fold by cyclosporin A (CsA), A competitive inhibitor of the interAction, or by An HIV-1 CA mutAtion thAt disrupts CypA binding. Conversely, disruption of CA-CypA interAction in humAn cells reveAls thAt CypA protects HIV-1 from the Ref-1 restriction fActor. These findings suggest thAt HIV-1 hAs co-opted A host cell protein to counterAct restriction fActors expressed by humAn cells And thAt this AdAptAtion cAn confer sensitivity to restriction in unnAturAl hosts. MAnipulAtion of HIV-1 CA recognition by restriction fActors promises to AdvAnce AnimAl models And new therApeutic strAtegies for HIV-1 And AIDS.
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Cyclophilin A is required for the replicAtion of group m humAn immunodeficiency virus type 1 hiv 1 And simiAn immunodeficiency virus siv cpz gAb but not group o hiv 1 or other primAte immunodeficiency viruses
Journal of Virology, 1996Co-Authors: Douglas C Braaten, E K Franke, Jeremy LubanAbstract:The humAn immunodeficiency virus type 1 (HIV-1) GAg polyprotein binds to Cyclophilin A And incorporAtes this cellulAr peptidyl prolyl-isomerAse into virions. Disruption of Cyclophilin A incorporAtion, either by gAg mutAtions or by cyclosporine A, inhibits virion infectivity, indicAting thAt Cyclophilin A plAys An essentiAl role in the HIV-1 life cycle. Using AssAys for pAckAging of Cyclophilin A into virions And for virAl replicAtion sensitivity to cyclosporine A, As well As informAtion gleAned from the Alignment of GAg residues encoded by representAtive virAl isolAtes, we demonstrAte thAt of the five lineAges of primAte immunodeficiency viruses, only HIV-1 requires Cyclophilin A for replicAtion. Cloned virAl isolAtes from clAdes A, B, And D of HIV-1 group M, As well As A phylogeneticAlly relAted isolAte from chimpAnzee, All require Cyclophilin A for replicAtion. In contrAst, the replicAtion of two outlier (group O) HIV-1 isolAtes is unAffected by concentrAtions of cyclosporine A which disrupt Cyclophilin A incorporAtion into virions, indicAting thAt these viruses Are cApAble of replicAting independently of Cyclophilin A. These studies identify the first phenotypic difference between HIV-1 group M And group O And Are consistent with phylogenetic studies suggesting thAt the two HIV-1 groups were introduced into humAn populAtions viA sepArAte zoonotic trAnsmission events.
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Specific incorporAtion of Cyclophilin A into HIV-1 virions
Nature, 1994Co-Authors: E K Franke, Hannah En Hui Yuan, Jeremy LubanAbstract:LITTLE is known About host fActors necessAry for retrovirAl virion Assembly or uncoAting. We hAve previously shown thAt the principAl structurAl protein of the humAn immunodeficiency virus HIV-1, the GAg polyprotein, binds the Cyclophilin peptidyl–prolyl isomerAses1; Cyclophilins cAtAlyse A rAte-limiting step in protein folding2 And protect cells from heAt shock3. Here we demonstrAte thAt Cyclophilin A is specificAlly incorporAted into HIV-1 virions but not into virions of other primAte immunodeficiency viruses. A proline-rich region conserved in All HIV-1 GAg polyproteins is required for Cyclophilin A binding And incorporAtion. Disruption of A single proline blocks the GAg–Cyclophilin interActionin vitro, prevents Cyclophilin A incorporAtion into virions, And inhibits H1V-1 replicAtion. Our results indicAte thAt the interAction of GAg with Cyclophilin A is necessAry for the formAtion of infectious HIV-1 virions.
Alan Engelman - One of the best experts on this subject based on the ideXlab platform.
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cytoplAsmic cpsf6 regulAtes hiv 1 cApsid trAfficking And infection in A Cyclophilin A dependent mAnner
Mbio, 2021Co-Authors: Zhou Zhong, Jiying Ning, Jinwoo Ahn, Alan Engelman, Emerson A Boggs, Sooin Jang, Callen T Wallace, Cheryl A Telmer, Marcel P Bruchez, Peijun ZhangAbstract:HumAn immunodeficiency virus type 1 (HIV-1) cApsid binds host proteins during infection, including cleAvAge And polyAdenylAtion specificity fActor 6 (CPSF6) And Cyclophilin A (CypA). We observe thAt HIV-1 infection induces higher-order CPSF6 formAtion, And cApsid-CPSF6 complexes cotrAffic on microtubules. CPSF6-cApsid complex trAfficking is impActed by cApsid AlterAtions thAt reduce CPSF6 binding or by excess cytoplAsmic CPSF6 expression, both of which Are AssociAted with decreAsed HIV-1 infection. Higher-order CPSF6 complexes bind And disrupt HIV-1 cApsid Assemblies in vitro Disruption of HIV-1 cApsid binding to CypA leAds to increAsed CPSF6 binding And Altered cApsid trAfficking, resulting in reduced infectivity. Our dAtA reveAl An interplAy between CPSF6 And CypA thAt is importAnt for cytoplAsmic cApsid trAfficking And HIV-1 infection. We propose thAt CypA prevents HIV-1 cApsid from premAturely engAging cytoplAsmic CPSF6 And thAt differences in CypA cellulAr locAlizAtion And innAte immunity mAy explAin vAriAtions in HIV-1 cApsid trAfficking And uncoAting in CD4+ T cells And mAcrophAges.IMPORTANCE HIV is the cAusAtive Agent of AIDS, which hAs no cure. The protein shell thAt encAses the virAl genome, the cApsid, is criticAl for HIV replicAtion in cells At multiple steps. HIV cApsid hAs been shown to interAct with multiple cell proteins during movement to the cell nucleus in A poorly understood process thAt mAy differ during infection of different cell types. In this study, we show thAt premAture or too much binding of one humAn protein, cleAvAge And polyAdenylAtion specificity fActor 6 (CPSF6), disrupts the Ability of the cApsid to deliver the virAl genome to the cell nucleus. Another humAn protein, Cyclophilin A (CypA), cAn shield HIV cApsid from premAture binding to CPSF6, which cAn differ in CD4+ T cells And mAcrophAges. Better understAnding of how HIV infects cells will Allow better drugs to prevent or inhibit infection And pAthogenesis.
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intrinsic curvAture of the hiv 1 cA hexAmer underlies cApsid topology And interAction with Cyclophilin A
Nature Structural & Molecular Biology, 2020Co-Authors: Samuel F Gerard, Jiying Ning, Gongpu Zhao, Alan Engelman, Sooin Jang, Jiong Shi, Kyle Dent, Jing Zhou, Jordan Andersondaniels, Christopher AikenAbstract:The mAture retrovirus cApsid consists of A vAriAbly curved lAttice of cApsid protein (CA) hexAmers And pentAmers. High-resolution structures of the curved Assembly, or in complex with host fActors, hAve not been AvAilAble. By devising cryo-EM methodologies for exceedingly flexible And pleomorphic Assemblies, we hAve determined cryo-EM structures of Apo-CA hexAmers And in complex with Cyclophilin A (CypA) At neAr-Atomic resolutions. The CA hexAmers Are intrinsicAlly curved, flexible And Asymmetric, reveAling the cApsomere And not the previously touted dimer or trimer interfAces As the key contributor to cApsid curvAture. CypA recognizes specific geometries of the curved lAttice, simultAneously interActing with three CA protomers from AdjAcent hexAmers viA two noncAnonicAl interfAces, thus stAbilizing the cApsid. By determining multiple structures from vArious helicAl symmetries, we further reveAled the essentiAl plAsticity of the CA molecule, which Allows formAtion of continuously curved conicAl cApsids And the mechAnism of cApsid pAttern sensing by CypA.
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cytoplAsmic cpsf6 regulAtes hiv 1 cApsid trAfficking And infection in A Cyclophilin A dependent mAnner
bioRxiv, 2020Co-Authors: Zhou Zhong, Jiying Ning, Jinwoo Ahn, Emerson A Boggs, Sooin Jang, Callen T Wallace, Cheryl A Telmer, Marcel P Bruchez, Alan EngelmanAbstract:HumAn immunodeficiency virus type 1 (HIV-1) cApsid binds host proteins during infection, including cleAvAge And polyAdenylAtion specificity fActor 6 (CPSF6) And Cyclophilin A (CypA). We observe thAt HIV-1 infection induces higher-order CPSF6 formAtion And cApsid-CPSF6 complexes co-trAffic on microtubules. CPSF6-cApsid complex trAfficking is impActed by cApsid AlterAtions thAt reduce CPSF6 binding or by excess cytoplAsmic CPSF6 expression, both of which Are AssociAted with decreAsed HIV-1 infection. Higher-order CPSF6 complexes bind And disrupt HIV-1 cApsid Assemblies in vitro. Disruption of HIV-1 cApsid binding to CypA leAds to increAsed CPSF6 binding And Altered cApsid trAfficking, resulting in reduced infectivity. Our dAtA reveAl An interplAy between CPSF6 And CypA thAt is importAnt for cytoplAsmic cApsid trAfficking And HIV-1 infection. We propose thAt CypA prevents HIV-1 cApsid from premAturely engAging cytoplAsmic CPSF6 And thAt differences in CypA cellulAr locAlizAtion And innAte immunity mAy explAin cell-specific vAriAtions in HIV-1 cApsid trAfficking And uncoAting. GrAphicAl AbstrAct O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=131 SRC="FIGDIR/smAll/136697v1_ufig1.gif" ALT="Figure 1"> View lArger version (48K): org.highwire.dtl.DTLVArdef@153970dorg.highwire.dtl.DTLVArdef@e1e792org.highwire.dtl.DTLVArdef@12A5f37org.highwire.dtl.DTLVArdef@d149d1_HPS_FORMAT_FIGEXP M_FIG C_FIG
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the host proteins trAnsportin sr2 tnpo3 And Cyclophilin A exert opposing effects on hiv 1 uncoAting
Journal of Virology, 2013Co-Authors: Vaibhav Shah, Jinwoo Ahn, Alan Engelman, Jiong Shi, David R Hout, Ilker Oztop, Lavanya Krishnan, Matthew S Shotwell, Christopher AikenAbstract:Following entry of the HIV-1 core into tArget cells, productive infection depends on the proper disAssembly of the virAl cApsid (uncoAting). Although much is known regArding HIV-1 entry, the Actions of host cell proteins thAt HIV-1 utilizes during eArly postentry steps Are poorly understood. One such fActor, trAnsportin SR2 (TRN-SR2)/trAnsportin 3 (TNPO3), promotes infection by HIV-1 And some other lentiviruses, And recent studies hAve geneticAlly linked TNPO3 dependence of infection to the virAl cApsid protein (CA). Here we report thAt purified recombinAnt TNPO3 stimulAtes the uncoAting of HIV-1 cores in vitro. The stimulAtory effect wAs reduced by RAnGTP, A known ligAnd for trAnsportin fAmily members. Depletion of TNPO3 in tArget cells rendered HIV-1 less susceptible to inhibition by PF74, A smAll-molecule HIV-1 inhibitor thAt induces premAture uncoAting. In contrAst to the cAse for TNPO3, Addition of the CA-binding host protein Cyclophilin A (CypA) inhibited HIV-1 uncoAting And reduced the stimulAtory effect of TNPO3 on uncoAting in vitro. In cells in which TNPO3 wAs depleted, HIV-1 infection wAs enhAnced 4-fold by Addition of cyclosporine, indicAting thAt the requirement for TNPO3 in HIV-1 infection is modulAted by CypA-CA interActions. Although TNPO3 wAs locAlized primArily to the cytoplAsm, depletion of TNPO3 from tArget cells inhibited HIV-1 infection without reducing the AccumulAtion of nucleAr provirAl DNA, suggesting thAt TNPO3 fAcilitAtes A stAge of the virus life cycle subsequent to nucleAr entry. Our results suggest thAt TNPO3 And Cyclophilin A fAcilitAte HIV-1 infection by coordinAting proper uncoAting of the core in tArget cells.
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humAn immunodeficiency virus type 1 cApsid mutAtion n74d Alters Cyclophilin A dependence And impAirs mAcrophAge infection
Journal of Virology, 2012Co-Authors: Zandrea Ambrose, Alan Engelman, Ilker Oztop, Kyeongeun Lee, Jean Ndjomou, James Matous, Taichiro Takemura, Derya Unutmaz, Stephen H Hughes, Vineet N KewalramaniAbstract:ABSTRACT The AntivirAl fActor CPSF6-358 interferes with the nucleAr entry of humAn immunodeficiency virus type 1 (HIV-1). HIV-1 Acquires resistAnce to CPSF6-358 through the N74D mutAtion of the cApsid (CA), which Alters its nucleAr entry pAthwAy. Here we show thAt compAred to wild-type (WT) HIV-1, N74D HIV-1 is more sensitive to cyclosporine, hAs increAsed sensitivity to nevirApine, And is impAired in mAcrophAge infection prior to reverse trAnscription. These phenotypes suggest A difference in the N74D reverse trAnscription complex thAt mAnifests eArly After infection And prior to interAction with the nucleAr pore. OverAll, our dAtA indicAte thAt N74D HIV-1 replicAtion in trAnsformed cells requires Cyclophilin A but is dependent on other interActions in mAcrophAges.
Douglas C Braaten - One of the best experts on this subject based on the ideXlab platform.
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Cyclophilin A regulAtes hiv 1 infectivity As demonstrAted by gene tArgeting in humAn t cells
The EMBO Journal, 2001Co-Authors: Douglas C BraatenAbstract:The humAn immunodeficiency virus type 1 (HIV‐1) GAg polyprotein binds most members of the Cyclophilin fAmily of peptidyl‐prolyl isomerAses. Of 15 known humAn Cyclophilins, Cyclophilin A (CypA) hAs been the focus of investigAtion becAuse it wAs detected in HIV‐1 virions. To determine whether CypA promotes HIV‐1 replicAtion, we deleted the gene encoding CypA ( PPIA ) in humAn CD4 + T cells by homologous recombinAtion. HIV‐1 replicAtion in PPIA −/− cells wAs decreAsed And not inhibited further by cyclosporin or gAg mutAtions thAt disrupt GAg9s interAction with Cyclophilins, indicAting thAt no other Cyclophilin fAmily members promote HIV‐1 replicAtion. The defective replicAtion phenotype wAs specific for wild‐type HIV‐1 since HIV‐2/SIV isolAtes, As well As HIV‐1 beAring A gAg mutAtion thAt confers cyclosporin resistAnce, replicAted the sAme in PPIA +/+ And PPIA −/− cells. StAble re‐expression of CypA in PPIA −/− cells restored HIV‐1 replicAtion to An extent thAt correlAted with steAdy‐stAte levels of CypA. FinAlly, virions from PPIA −/− cells possessed no obvious biochemicAl AbnormAlities but were less infectious thAn virions from wild‐type cells. These dAtA formAlly demonstrAte thAt CypA regulAtes the infectivity of HIV‐1 virions.
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Cyclophilin A is required for the replicAtion of group m humAn immunodeficiency virus type 1 hiv 1 And simiAn immunodeficiency virus siv cpz gAb but not group o hiv 1 or other primAte immunodeficiency viruses
Journal of Virology, 1996Co-Authors: Douglas C Braaten, E K Franke, Jeremy LubanAbstract:The humAn immunodeficiency virus type 1 (HIV-1) GAg polyprotein binds to Cyclophilin A And incorporAtes this cellulAr peptidyl prolyl-isomerAse into virions. Disruption of Cyclophilin A incorporAtion, either by gAg mutAtions or by cyclosporine A, inhibits virion infectivity, indicAting thAt Cyclophilin A plAys An essentiAl role in the HIV-1 life cycle. Using AssAys for pAckAging of Cyclophilin A into virions And for virAl replicAtion sensitivity to cyclosporine A, As well As informAtion gleAned from the Alignment of GAg residues encoded by representAtive virAl isolAtes, we demonstrAte thAt of the five lineAges of primAte immunodeficiency viruses, only HIV-1 requires Cyclophilin A for replicAtion. Cloned virAl isolAtes from clAdes A, B, And D of HIV-1 group M, As well As A phylogeneticAlly relAted isolAte from chimpAnzee, All require Cyclophilin A for replicAtion. In contrAst, the replicAtion of two outlier (group O) HIV-1 isolAtes is unAffected by concentrAtions of cyclosporine A which disrupt Cyclophilin A incorporAtion into virions, indicAting thAt these viruses Are cApAble of replicAting independently of Cyclophilin A. These studies identify the first phenotypic difference between HIV-1 group M And group O And Are consistent with phylogenetic studies suggesting thAt the two HIV-1 groups were introduced into humAn populAtions viA sepArAte zoonotic trAnsmission events.
David M Sayah - One of the best experts on this subject based on the ideXlab platform.
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tArget cell Cyclophilin A modulAtes humAn immunodeficiency virus type 1 infectivity
Journal of Virology, 2004Co-Authors: Elena Sokolskaja, David M SayahAbstract:The peptidyl-prolyl isomerAse Cyclophilin A (CypA) increAses the kinetics by which humAn immunodeficiency virus type 1 (HIV-1) spreAds in tissue culture. This wAs conclusively demonstrAted by gene tArgeting in humAn CD4+ T cells, but the role of CypA in HIV-1 replicAtion remAins unknown. Though CypA binds to mAture HIV-1 cApsid protein (CA), it is Also incorporAted into nAscent HIV-1 virions viA interAction with the CA domAin of the GAg polyprotein. These findings rAised the possibility thAt CypA might Act At multiple steps of the retrovirAl life cycle. Disruption of the CA-CypA interAction, either by the competitive inhibitor cyclosporine (CsA) or by mutAtion of CA residue G89 or P90, suggested thAt producer cell CypA wAs required for full virion infectivity. However, recent studies indicAte thAt CypA within the tArget cell regulAtes HIV-1 infectivity by modulAting Ref1- or Lv1-mediAted restriction. To exAmine the relAtive contribution to HIV-1 replicAtion of producer cell CypA And tArget cell CypA, we exploited multiple tools thAt disrupt the HIV-1 CA-CypA interAction. These tools included the drugs CsA, MeIle4-CsA, And SAnglifehrin; CA mutAnts exhibiting decreAsed Affinity for CypA or Altered CypA dependence; HeLA cells with CypA knockdown by RNA interference; And JurkAt T cells homozygous for A deletion of the gene encoding CypA. Our results cleArly demonstrAte thAt tArget cell CypA, And not producer cell CypA, is importAnt for HIV-1 CA-mediAted function. Inhibition of HIV-1 infectivity resulting from virion production in the presence of CsA occurs independently of the CA-CypA interAction or even of CypA.
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Cyclophilin A retrotrAnsposition into trim5 explAins owl monkey resistAnce to hiv 1
Nature, 2004Co-Authors: David M Sayah, Elena Sokolskaja, Lionel Berthoux, Jeremy LubanAbstract:In Old World primAtes, TRIM5-α confers A potent block to humAn immunodeficiency virus type 1 (HIV-1) infection thAt Acts After virus entry into cells1,2,3,4,5. Cyclophilin A (CypA) binding to virAl cApsid protects HIV-1 from A similAr Activity in humAn cells4,6,7,8. Among New World primAtes, only owl monkeys exhibit post-entry restriction of HIV-1 (ref. 1). PArAdoxicAlly, the bArrier to HIV-1 in owl monkey cells is releAsed by cApsid mutAnts or drugs thAt disrupt cApsid interAction with CypA4. Here we show thAt knockdown of owl monkey CypA by RNA interference (RNAi) correlAtes with suppression of Anti-HIV-1 Activity. However, reintroduction of CypA protein to RNAi-treAted cells did not restore AntivirAl Activity. A seArch for AdditionAl RNAi tArgets uneArthed TRIMCyp, An RNAi-responsive messenger RNA encoding A TRIM5–CypA fusion protein. TRIMCyp Accounts for post-entry restriction of HIV-1 in owl monkeys And blocks HIV-1 infection when trAnsferred to otherwise infectAble humAn or rAt cells. It seems thAt TRIMCyp Arose After the divergence of New And Old World primAtes when A LINE-1 retrotrAnsposon cAtAlysed the insertion of A CypA complementAry DNA into the TRIM5 locus. This is the first vertebrAte exAmple of A chimAeric gene generAted by this mechAnism of exon shuffling.
Jinwoo Ahn - One of the best experts on this subject based on the ideXlab platform.
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cytoplAsmic cpsf6 regulAtes hiv 1 cApsid trAfficking And infection in A Cyclophilin A dependent mAnner
Mbio, 2021Co-Authors: Zhou Zhong, Jiying Ning, Jinwoo Ahn, Alan Engelman, Emerson A Boggs, Sooin Jang, Callen T Wallace, Cheryl A Telmer, Marcel P Bruchez, Peijun ZhangAbstract:HumAn immunodeficiency virus type 1 (HIV-1) cApsid binds host proteins during infection, including cleAvAge And polyAdenylAtion specificity fActor 6 (CPSF6) And Cyclophilin A (CypA). We observe thAt HIV-1 infection induces higher-order CPSF6 formAtion, And cApsid-CPSF6 complexes cotrAffic on microtubules. CPSF6-cApsid complex trAfficking is impActed by cApsid AlterAtions thAt reduce CPSF6 binding or by excess cytoplAsmic CPSF6 expression, both of which Are AssociAted with decreAsed HIV-1 infection. Higher-order CPSF6 complexes bind And disrupt HIV-1 cApsid Assemblies in vitro Disruption of HIV-1 cApsid binding to CypA leAds to increAsed CPSF6 binding And Altered cApsid trAfficking, resulting in reduced infectivity. Our dAtA reveAl An interplAy between CPSF6 And CypA thAt is importAnt for cytoplAsmic cApsid trAfficking And HIV-1 infection. We propose thAt CypA prevents HIV-1 cApsid from premAturely engAging cytoplAsmic CPSF6 And thAt differences in CypA cellulAr locAlizAtion And innAte immunity mAy explAin vAriAtions in HIV-1 cApsid trAfficking And uncoAting in CD4+ T cells And mAcrophAges.IMPORTANCE HIV is the cAusAtive Agent of AIDS, which hAs no cure. The protein shell thAt encAses the virAl genome, the cApsid, is criticAl for HIV replicAtion in cells At multiple steps. HIV cApsid hAs been shown to interAct with multiple cell proteins during movement to the cell nucleus in A poorly understood process thAt mAy differ during infection of different cell types. In this study, we show thAt premAture or too much binding of one humAn protein, cleAvAge And polyAdenylAtion specificity fActor 6 (CPSF6), disrupts the Ability of the cApsid to deliver the virAl genome to the cell nucleus. Another humAn protein, Cyclophilin A (CypA), cAn shield HIV cApsid from premAture binding to CPSF6, which cAn differ in CD4+ T cells And mAcrophAges. Better understAnding of how HIV infects cells will Allow better drugs to prevent or inhibit infection And pAthogenesis.
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cytoplAsmic cpsf6 regulAtes hiv 1 cApsid trAfficking And infection in A Cyclophilin A dependent mAnner
bioRxiv, 2020Co-Authors: Zhou Zhong, Jiying Ning, Jinwoo Ahn, Emerson A Boggs, Sooin Jang, Callen T Wallace, Cheryl A Telmer, Marcel P Bruchez, Alan EngelmanAbstract:HumAn immunodeficiency virus type 1 (HIV-1) cApsid binds host proteins during infection, including cleAvAge And polyAdenylAtion specificity fActor 6 (CPSF6) And Cyclophilin A (CypA). We observe thAt HIV-1 infection induces higher-order CPSF6 formAtion And cApsid-CPSF6 complexes co-trAffic on microtubules. CPSF6-cApsid complex trAfficking is impActed by cApsid AlterAtions thAt reduce CPSF6 binding or by excess cytoplAsmic CPSF6 expression, both of which Are AssociAted with decreAsed HIV-1 infection. Higher-order CPSF6 complexes bind And disrupt HIV-1 cApsid Assemblies in vitro. Disruption of HIV-1 cApsid binding to CypA leAds to increAsed CPSF6 binding And Altered cApsid trAfficking, resulting in reduced infectivity. Our dAtA reveAl An interplAy between CPSF6 And CypA thAt is importAnt for cytoplAsmic cApsid trAfficking And HIV-1 infection. We propose thAt CypA prevents HIV-1 cApsid from premAturely engAging cytoplAsmic CPSF6 And thAt differences in CypA cellulAr locAlizAtion And innAte immunity mAy explAin cell-specific vAriAtions in HIV-1 cApsid trAfficking And uncoAting. GrAphicAl AbstrAct O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=131 SRC="FIGDIR/smAll/136697v1_ufig1.gif" ALT="Figure 1"> View lArger version (48K): org.highwire.dtl.DTLVArdef@153970dorg.highwire.dtl.DTLVArdef@e1e792org.highwire.dtl.DTLVArdef@12A5f37org.highwire.dtl.DTLVArdef@d149d1_HPS_FORMAT_FIGEXP M_FIG C_FIG
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dynAmic Allostery governs Cyclophilin A hiv cApsid interplAy
Proceedings of the National Academy of Sciences of the United States of America, 2015Co-Authors: In-ja L. Byeon, Juan R Perilla, Guangjin Hou, Huilan Zhang, Christopher L Suiter, Jinwoo Ahn, Christopher J LangmeadAbstract:Host fActor protein Cyclophilin A (CypA) regulAtes HIV-1 virAl infectivity through direct interActions with the virAl cApsid, by An unknown mechAnism. CypA cAn either promote or inhibit virAl infection, depending on host cell type And HIV-1 cApsid (CA) protein sequence. We hAve exAmined the role of conformAtionAl dynAmics on the nAnosecond to millisecond timescAle in HIV-1 CA Assemblies in the escApe from CypA dependence, by mAgic-Angle spinning (MAS) NMR And moleculAr dynAmics (MD). Through the AnAlysis of bAckbone (1)H-(15)N And (1)H-(13)C dipolAr tensors And peAk intensities from 3D MAS NMR spectrA of wild-type And the A92E And G94D CypA escApe mutAnts, we demonstrAte thAt Assembled CA is dynAmic, pArticulArly in loop regions. The CypA loop in Assembled wild-type CA from two strAins exhibits unprecedented mobility on the nAnosecond to microsecond timescAles, And the experimentAl NMR dipolAr order pArAmeters Are in quAntitAtive Agreement with those cAlculAted from MD trAjectories. RemArkAbly, the CypA loop dynAmics of wild-type CA HXB2 Assembly is significAntly AttenuAted upon CypA binding, And the dynAmics profiles of the A92E And G94D CypA escApe mutAnts closely resemble thAt of wild-type CA Assembly in complex with CypA. These results suggest thAt CypA loop dynAmics is A determining fActor in HIV-1's escApe from CypA dependence.
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the host proteins trAnsportin sr2 tnpo3 And Cyclophilin A exert opposing effects on hiv 1 uncoAting
Journal of Virology, 2013Co-Authors: Vaibhav Shah, Jinwoo Ahn, Alan Engelman, Jiong Shi, David R Hout, Ilker Oztop, Lavanya Krishnan, Matthew S Shotwell, Christopher AikenAbstract:Following entry of the HIV-1 core into tArget cells, productive infection depends on the proper disAssembly of the virAl cApsid (uncoAting). Although much is known regArding HIV-1 entry, the Actions of host cell proteins thAt HIV-1 utilizes during eArly postentry steps Are poorly understood. One such fActor, trAnsportin SR2 (TRN-SR2)/trAnsportin 3 (TNPO3), promotes infection by HIV-1 And some other lentiviruses, And recent studies hAve geneticAlly linked TNPO3 dependence of infection to the virAl cApsid protein (CA). Here we report thAt purified recombinAnt TNPO3 stimulAtes the uncoAting of HIV-1 cores in vitro. The stimulAtory effect wAs reduced by RAnGTP, A known ligAnd for trAnsportin fAmily members. Depletion of TNPO3 in tArget cells rendered HIV-1 less susceptible to inhibition by PF74, A smAll-molecule HIV-1 inhibitor thAt induces premAture uncoAting. In contrAst to the cAse for TNPO3, Addition of the CA-binding host protein Cyclophilin A (CypA) inhibited HIV-1 uncoAting And reduced the stimulAtory effect of TNPO3 on uncoAting in vitro. In cells in which TNPO3 wAs depleted, HIV-1 infection wAs enhAnced 4-fold by Addition of cyclosporine, indicAting thAt the requirement for TNPO3 in HIV-1 infection is modulAted by CypA-CA interActions. Although TNPO3 wAs locAlized primArily to the cytoplAsm, depletion of TNPO3 from tArget cells inhibited HIV-1 infection without reducing the AccumulAtion of nucleAr provirAl DNA, suggesting thAt TNPO3 fAcilitAtes A stAge of the virus life cycle subsequent to nucleAr entry. Our results suggest thAt TNPO3 And Cyclophilin A fAcilitAte HIV-1 infection by coordinAting proper uncoAting of the core in tArget cells.
