Identification of a Novel HIV-1 Inhibitor Targeting Vif-dependent Degradation of Human APOBEC3G Protein

Autor: Marie K. Mankowski, N. Miranda Nebane, Andrew Jay Brazier, Sara J. Buhrlage, Vikas Misra, Dana Gabuzda, Erez Pery, Roger G. Ptak, Lynn Rasmussen, Kottampatty S. Rajendran, Ann M. Sheehy, E. Lucile White
Rok vydání: 2015
Předmět:
Zdroj: Journal of Biological Chemistry. 290:10504-10517
ISSN: 0021-9258
DOI: 10.1074/jbc.m114.626903
Popis: APOBEC3G (A3G) is a cellular cytidine deaminase that restricts HIV-1 replication by inducing G-to-A hypermutation in viral DNA and by deamination-independent mechanisms. HIV-1 Vif binds to A3G, resulting in its degradation via the 26 S proteasome. Therefore, this interaction represents a potential therapeutic target. To identify compounds that inhibit interaction between A3G and HIV-1 Vif in a high throughput format, we developed a homogeneous time-resolved fluorescence resonance energy transfer assay. A 307,520 compound library from the NIH Molecular Libraries Small Molecule Repository was screened. Secondary screens to evaluate dose-response performance and off-target effects, cell-based assays to identify compounds that attenuate Vif-dependent degradation of A3G, and assays testing antiviral activity in peripheral blood mononuclear cells and T cells were employed. One compound, N.41, showed potent antiviral activity in A3G(+) but not in A3G(−) T cells and had an IC50 as low as 8.4 μm and a TC50 of >100 μm when tested against HIV-1Ba-L replication in peripheral blood mononuclear cells. N.41 inhibited the Vif-A3G interaction and increased cellular A3G levels and incorporation of A3G into virions, thereby attenuating virus infectivity in a Vif-dependent manner. N.41 activity was also species- and Vif-dependent. Preliminary structure-activity relationship studies suggest that a hydroxyl moiety located at a phenylamino group is critical for N.41 anti-HIV activity and identified N.41 analogs with better potency (IC50 as low as 4.2 μm). These findings identify a new lead compound that attenuates HIV replication by liberating A3G from Vif regulation and increasing its innate antiviral activity.
Databáze: OpenAIRE