title: Mechanisms of human immunodeficiency virus type 1 concerted integration related to strand transfer inhibition and drug resistance.
abstract: The "strand transfer inhibitors" of human immunodeficiency virus type-1 (HIV-1) integrase (IN), so named because of their pronounced selectivity for inhibiting strand transfer over 3' OH processing, block virus replication in vivo and ex vivo and prevent concerted integration in vitro. We explored the kinetics of product formation and strand transfer inhibition within reconstituted synaptic complexes capable of concerted integration. Synaptic complexes were formed with viral DNA donors containing either two blunt ends, two 3'-OH-processed ends, or one of each. We determined that one blunt end within a synaptic complex is a sufficient condition for low-nanomolar-range strand transfer inhibition with naphthyridine carboxamide inhibitors L-870,810 and L-870,812. We further explored the catalytic properties and drug resistance profiles of a set of clinically relevant strand transfer inhibitor-resistant HIV-1 IN mutants. The diketo acids and naphthyridine carboxamides, mechanistically similar but structurally distinct strand transfer inhibitors, each select for a distinct set of drug resistance mutations ex vivo. The S153Y and N155S IN resistance mutants were selected with the diketo acid L-841,411, and the N155H mutant was selected with L-810,812. Each mutant exhibited some degree of catalytic impairment relative to the activity of wild type IN, although the N155H mutant displayed near-wild-type IN activities. The resistance profiles indicated that the S153Y mutation potentiates susceptibility to L-870,810 and L-870,812, while the N155S mutation confers resistance to L-870,810 and L-870,812. The N155H mutation confers resistance to L-870,810 and potentiates susceptibility to L-841,411. This study illuminates the interrelated mechanisms of concerted integration, strand transfer inhibition, and resistance to strand transfer inhibitors.
authors.affiliation: Institute for Molecular Virology, Saint Louis University Health Sciences Center, St Louis, Missouri 63104, USA.
authors.forename: Jacob A
authors.initials: JA
authors.lastname: Zahm
authors.forename: Sibes
authors.initials: S
authors.lastname: Bera
authors.forename: Krishan K
authors.initials: KK
authors.lastname: Pandey
authors.forename: Ajaykumar
authors.initials: A
authors.lastname: Vora
authors.forename: Kara
authors.initials: K
authors.lastname: Stillmock
authors.forename: Daria
authors.initials: D
authors.lastname: Hazuda
authors.forename: Duane P
authors.initials: DP
authors.lastname: Grandgenett
mesh_terms: D019380:Anti-HIV Agents / Q000494:pharmacology; D004279:DNA, Viral / Q000187:drug effects / Q000378:metabolism; D024882:Drug Resistance, Viral / Q000187:drug effects / Q000235:genetics; D019427:HIV Integrase / Q000737:chemistry / Q000187:drug effects / Q000235:genetics; D019428:HIV Integrase Inhibitors / Q000494:pharmacology*; D015497:HIV-1 / Q000187:drug effects* / Q000201:enzymology / Q000235:genetics; D006801:Humans; D020128:Inhibitory Concentration 50; D007651:Keto Acids / Q000494:pharmacology*; D008826:Microbial Sensitivity Tests / Q000379:methods; D009154:Mutation; D009287:Naphthyridines / Q000737:chemistry / Q000494:pharmacology*; D016662:Virus Integration / Q000187:drug effects* / Q000235:genetics
chemical_list: D019380:Anti-HIV Agents; D004279:DNA, Viral; D019428:HIV Integrase Inhibitors; D007651:Keto Acids; C524755:L-841,411; C489415:L870810; D009287:Naphthyridines; D019427:HIV Integrase