I ETVECTEURS RETROVIRAUX EXAMENUE " RETROVIRUS ' MLANDREOLA (5 Novembre 2007)

et al.,PN4S,2007,104,8316. Hayouka 1) (10/20) Analysede I'article sont miméesdansce a. Figure3 : Quellesétapesdu cyclede réplication l'expérience. test in vitro? Décrirebrièvement décritsdansla figure5 A à 5 F. Décrire les résultats b. Figure5 : Expliquer utilisées. d'unefaçonsuccinteles méthodologies de I'intégrase est proposédans c. Quel nouveaumécanismed'inhibition l'article?Est-il différentdu mécanismed'inhibitiondes inhibiteurs en phased'essaiclinique? dikétoacides actuellement

2) (5t2o) Exposerles principesde I'utilisationdes vecteurs rétrovirauxpour la thérapie génique. dans le domainede l'hématolllustrerpar un exemplede succèsthérapeutique immunologie.

3) (5/20) Quelles sont les différences principalesentre les hepadnaviridaeet les ? caulimoviridae

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Zvi Hayouka*, JosephRosenbluhl,Aviad Levint+.shoshanaLoya5,Mario Lebendiked, Dmitry veprintsevrl, Moshe Kotler*, Amnon Hizis.Abrâham Loyterr, and Assaf Friedler*'** rDepartment of Organic Chemistry,lDepartment of giologi(al Chemisùy,îProtein Purification Unit, Hebrew University of Jerusalem,Givat Ram,Jerusâlem gig6+, tsruut;toepufoment of path;togy, Hebrew Univerriiy-HadassahMedicalSchool, Jerusalem91120, krael; sDepartmenl of Cell and Developmental lcentre for Prot€in Engineering, Medi(al Researchcouncil cenlre, àiotogy.rtre sac*ter school of Medicin;, Tel aviv university, Tel aviv 69978, lsrael;and HillsRo a d ,C a m b r i d g eC B 22 QH,Un ite d Kin g d o m (receivedfor review January30, 2007) Edited by Roger D. Kornberg, Stan{ord University Schoolof Medicine, stantord, CA, and approved March 27, 2007

this approachto designpotent inhibitorsof HIV-1 integrase(IN) proteln' Currently,the clinically approvedanii-HIV drugsinhibit the viral enzymesreversetransciptase and proteaseor preventthe penetration of HIV-I into cells (7). The major problem with anti-HIV therapyis the high mutation rate in the viml genome, resultingin the emergenceof drug-resistantvirus strains.Thus, there is a constant need to identify ne\Ydrug targets and to developdrugs directed agailst them. An attractiveapproachis to inhibit the oligomerization of the viral enzymes.Attempts were made to developrnoleculesthat competitivelvbind at the suchmoleculeswerenot dimerizationinterfaces(8, 9). into èlfiFent inhibitors

the oligomedzationequilibrium as an alternative and more effectiveapproachto disrupt protein oligomerization and demonstrateits application for inhibition of IN. viral DNA IN catalyzesintegration of the reverse-transcribed into the host genome.It is çssentialfor HIV-1 replication,and mammalian cells do not harbor homologous enzymes.Theint glgljgljpçggglby two steps(11); (l) 3' end processi"g,;q IN createsthe

I drugdetign a!lorteryI proteinequilibrium I shiftides I peptides thatshiflproteinequilibriais of great he designof molecules potential, in the casesof aLloas demonstrated I therapeutic betweenactiveand the equilibrium which shift inhibitors, steric inactive(R and T) states,and chemicalchaperones,which shift folding equilibriumofproteins. Here, we proposethe shiftingof the oligomerizatioû equilibrium of proteins as a powerful method to modulatetheir activity.Our approachis basedon the allostericmodel (1), accordingto which an allostericprotein is in equilibrium betweenR and T states,and ligand binding can shilt this equilibriumtoward one ofthe states.This approachwas used therapeuticallyto devçlop moleculesfor the treatment of sickle cell anemia by heterotropic ligands that shift the R/T equilibrium of hemoglobintoward th€ high-afiinity R state (2). A similar principle is applied for the development of drugs againstprotein-misfoldingdiseases(3): Chemical, or pharmacôlogicai,chaperonesspecificallybind the native statesof misfoldéd proteins and shift the folding equilibrium toward the native siate,leadingto protein refolding and reactivation(4, 5) We have describeda peptidic chemicalchaperonethat refolds . and reactivatesoncogénicmutants of the tumor supPressorp53 (6). In this articte,we expandthe applicationoi shifting p,rotein equilibrium as a potential therapeuticstrategyand describeihe dévelopmentof "shiftides": a class of peptides that inhibits protei;s by shifting their oligomerizationequilibrium.We apply

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8316-8321 | PNAsI Mây15,2007| vol loa I no 20

and(4-)ltrand LTRslTterreversetranscriplionin thecytoplasm; lransler-whlch ls-alter nuclearrmDorl.lnleprallonoTlne vlral oN,l rîmptateinto tIe raaet hosi DNA. lil is in equilibrium among dirneric, tetrame c, and high-order oligomeric states (12-14).Dimeric IN binds at each end of the,vimlDNAiudng rhe 3' ehA-pi-ocèsi@in-Tnef$oplasm { l5). After nuclear imDorl.Ihe two LTR DNA-bound dimersapproacheâchothcr in the presence of the cellularprotein lcnseprthellum-derrySg andthe rffi-Ëramer,

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occurstet-rarirer doesnotbindDN4 ljlsqly, aq4{gqm_e+_zq!ion L2). onlybv the interactionbetweer two DNA-bound and

requiresbindingto the 75 (18),which activatesIN,|, vitro and Author (ont.ibutions: 2.H., M.K.,4.H., A, toytea and A.f designedresea.ch;Z H.,l R- A Levin,5.1..D.V.,M.1..ând a.F. pedormed retearch,M t contributed new reagents/ônôlt'tic toolrj 2.H,, J.R.,A. Levin, 5,!,, ând Â.F. analyz€d data; and Z H, M K-, ônd A.F. wrote the thê âuthois declare no conflictof interett. Thi! article i5 a PNASDirect SubmittionÂbbfeviationt: lN, iâtegràsê;LEOGF,lens êPithelium_defivedgrowth fâctor; AUC à.ârr4_ icalulÙacentrifugationl Mol, multipticity ofinfection; MAGI, multinudea. activatio^ ofa gala