title: The A128T resistance mutation reveals aberrant protein multimerization as the primary mechanism of action of allosteric HIV-1 integrase inhibitors.
abstract: Allosteric HIV-1 integrase (IN) inhibitors (ALLINIs) are a very promising new class of anti-HIV-1 agents that exhibit a multimodal mechanism of action by allosterically modulating IN multimerization and interfering with IN-lens epithelium-derived growth factor (LEDGF)/p75 binding. Selection of viral strains under ALLINI pressure has revealed an A128T substitution in HIV-1 IN as a primary mechanism of resistance. Here, we elucidated the structural and mechanistic basis for this resistance. The A128T substitution did not affect the hydrogen bonding between ALLINI and IN that mimics the IN-LEDGF/p75 interaction but instead altered the positioning of the inhibitor at the IN dimer interface. Consequently, the A128T substitution had only a minor effect on the ALLINI IC50 values for IN-LEDGF/p75 binding. Instead, ALLINIs markedly altered the multimerization of IN by promoting aberrant higher order WT (but not A128T) IN oligomers. Accordingly, WT IN catalytic activities and HIV-1 replication were potently inhibited by ALLINIs, whereas the A128T substitution in IN resulted in significant resistance to the inhibitors both in vitro and in cell culture assays. The differential multimerization of WT and A128T INs induced by ALLINIs correlated with the differences in infectivity of HIV-1 progeny virions. We conclude that ALLINIs primarily target IN multimerization rather than IN-LEDGF/p75 binding. Our findings provide the structural foundations for developing improved ALLINIs with increased potency and decreased potential to select for drug resistance.
authors.affiliation: Center for Retrovirus Research, College of Pharmacy, The Ohio State University, Columbus, Ohio 43210, USA.
authors.forename: Lei
authors.initials: L
authors.lastname: Feng
authors.forename: Amit
authors.initials: A
authors.lastname: Sharma
authors.forename: Alison
authors.initials: A
authors.lastname: Slaughter
authors.forename: Nivedita
authors.initials: N
authors.lastname: Jena
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Koh
authors.forename: Nikolozi
authors.initials: N
authors.lastname: Shkriabai
authors.forename: Ross C
authors.initials: RC
authors.lastname: Larue
authors.forename: Pratiq A
authors.initials: PA
authors.lastname: Patel
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Mitsuya
authors.forename: Jacques J
authors.initials: JJ
authors.lastname: Kessl
authors.forename: Alan
authors.initials: A
authors.lastname: Engelman
authors.forename: James R
authors.initials: JR
authors.lastname: Fuchs
authors.forename: Mamuka
authors.initials: M
authors.lastname: Kvaratskhelia
mesh_terms: D000494:Allosteric Regulation / Q000187:drug effects / Q000235:genetics; D019943:Amino Acid Substitution; D024882:Drug Resistance, Viral / Q000187:drug effects*; D057809:HEK293 Cells; D019427:HIV Integrase / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D019428:HIV Integrase Inhibitors / Q000737:chemistry / Q000494:pharmacology*; D015497:HIV-1 / Q000737:chemistry / Q000502:physiology*; D006367:HeLa Cells; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D020125:Mutation, Missense; D011485:Protein Binding; D055503:Protein Multimerization / Q000187:drug effects*; D014779:Virus Replication / Q000187:drug effects*
chemical_list: D019428:HIV Integrase Inhibitors; D036341:Intercellular Signaling Peptides and Proteins; C119380:lens epithelium-derived growth factor; D019427:HIV Integrase
keywords: Allosteric Inhibitors; Drug Resistance; HIV-1; Infectious Diseases; Integrase; Pharmacology; Protein-DNA Interactions; Protein-Drug Integrations; Protein-Protein Interactions; Structural Biology