New Class of HIV-1 Integrase (IN) Inhibitors with a Dual Mode of Action

• Published in: The Journal of biological chemistry 2012-06, Vol.287 (25), p.21189-21203
• Main Authors: Tsiang, Manuel, Jones, Gregg S., Niedziela-Majka, Anita, Kan, Elaine, Lansdon, Eric B., Huang, Wayne, Hung, Magdeleine, Samuel, Dharmaraj, Novikov, Nikolai, Xu, Yili, Mitchell, Michael, Guo, Hongyan, Babaoglu, Kerim, Liu, Xiaohong, Geleziunas, Romas, Sakowicz, Roman
• Format: Article
• Language: English
• Subjects: Acetates - chemistry; Acetates - pharmacology; Adaptor Proteins, Signal Transducing - genetics; Adaptor Proteins, Signal Transducing - metabolism; Allosteric Inhibitor; Antiviral Agents; Antiviral Mechanism; Cell Line; Chromatin - genetics; Chromatin - metabolism; Crystal Structure; DNA, Viral - genetics; DNA, Viral - metabolism; Enzymology; Fluorescence Resonance Energy Transfer (FRET); HIV Infections - drug therapy; HIV Infections - enzymology; HIV Infections - genetics; HIV Integrase - chemistry; HIV Integrase - genetics; HIV Integrase - metabolism; HIV Integrase Inhibitors - chemistry; HIV Integrase Inhibitors - pharmacology; HIV-1; HIV-1 - enzymology; HIV-1 - genetics; Humans; Integrase; Quinolines - chemistry; Quinolines - pharmacology; Transcription Factors - genetics; Transcription Factors - metabolism; Virus Integration - drug effects; Virus Integration - physiology
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1074/jbc.M112.347534

tert-Butoxy-(4-phenyl-quinolin-3-yl)-acetic acids (tBPQA) are a new class of HIV-1 integrase (IN) inhibitors that are structurally distinct from IN strand transfer inhibitors but analogous to LEDGINs. LEDGINs are a class of potent antiviral compounds that interacts with the lens epithelium-derived growth factor (LEDGF) binding pocket on IN and were identified through competition binding against LEDGF. LEDGF tethers IN to the host chromatin and enables targeted integration of viral DNA. The prevailing understanding of the antiviral mechanism of LEDGINs is that they inhibit LEDGF binding to IN, which prevents targeted integration of HIV-1. We showed that in addition to the properties already known for LEDGINs, the binding of tBPQAs to the IN dimer interface inhibits IN enzymatic activity in a LEDGF-independent manner. Using the analysis of two long terminal repeat junctions in HIV-infected cells, we showed that the inhibition by tBPQAs occurs at or prior to the viral DNA 3′-processing step. Biochemical studies revealed that this inhibition operates by compound-induced conformational changes in the IN dimer that prevent proper assembly of IN onto viral DNA. For the first time, tBPQAs were demonstrated to be allosteric inhibitors of HIV-1 IN displaying a dual mode of action: inhibition of IN-viral DNA assembly and inhibition of IN-LEDGF interaction. Competitors of LEDGF binding to HIV-1 integrase could prevent targeted integration to chromatin. LEDGF competitors like tBPQAs were also found to inhibit integrase enzyme activity by preventing proper integrase-viral DNA assembly. tBPQAs are allosteric inhibitors of integrase with a dual mode of action. Interference with two distinct steps of integration through the same binding site represents a new antiviral paradigm.