The phenylmethylthiazolylthiourea nonnucleoside reverse transcriptase (RT) inhibitor MSK-076 selects for a resistance mutation in the active site of human immunodeficiency virus type 2 RT.
The phenylmethylthiazolylthiourea (PETT) derivative MSK-076 shows, besides high potency against human immunodeficiency virus type 1 (HIV-1), marked activity against HIV-2 (50% effective concentration, 0.63 microM) in cell culture. Time-of-addition experiments pointed to HIV-2 reverse transcriptase (RT) as the target of action of MSK-076. Recombinant HIV-2 RT was inhibited by MSK-076 at 23 microM. As was also found for HIV-1 RT, MSK-076 inhibited HIV-2 RT in a noncompetitive manner with respect to dGTP and poly(rC).oligo(dG) as the substrate and template-primer, respectively. MSK-076 selected for A101P and G112E mutations in HIV-2 RT and for K101E, Y181C, and G190R mutations in HIV-1 RT. The selected mutated strains of HIV-2 were fully resistant to MSK-076, and the mutant HIV-2 RT enzymes into which the A101P and/or G112E mutation was introduced by site-directed mutagenesis showed more than 50-fold resistance to MSK-076. Mapping of the resistance mutations to the HIV-2 RT structure ascertained that A101P is located at a position equivalent to the nonnucleoside RT inhibitor (NNRTI)-binding site of HIV-1 RT. G112E, however, is distal to the putative NNRTI-binding site in HIV-2 RT but close to the active site, implying a novel molecular mode of action and mechanism of resistance. Our findings have important implications for the development of new NNRTIs with pronounced activity against a wider range of lentiviruses.
Auwerx
Joeri
J
Rega Institute for Medical Research, B-3000 Leuven, Belgium.
Stevens
Miguel
M
Van Rompay
An R
AR
Bird
Louise E
LE
Ren
Jingshan
J
De Clercq
Erik
E
Oberg
Bo
B
Stammers
David K
DK
Karlsson
Anna
A
Balzarini
Jan
J
D000595:Amino Acid Sequence; D019380:Anti-HIV Agents / Q000494:pharmacology*; D002478:Cells, Cultured; D003588:Cytopathogenic Effect, Viral; D024882:Drug Resistance, Viral; D054303:HIV Reverse Transcriptase; D015497:HIV-1 / Q000187:drug effects; D015498:HIV-2 / Q000187:drug effects* / Q000201:enzymology / Q000235:genetics; D006801:Humans; D008826:Microbial Sensitivity Tests; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009154:Mutation; D012194:RNA-Directed DNA Polymerase / Q000737:chemistry / Q000187:drug effects* / Q000235:genetics; D018894:Reverse Transcriptase Inhibitors / Q000494:pharmacology*; D013844:Thiazoles / Q000737:chemistry / Q000494:pharmacology*; D014230:Triazoles / Q000737:chemistry / Q000494:pharmacology*
D019380:Anti-HIV Agents; D018894:Reverse Transcriptase Inhibitors; D013844:Thiazoles; D014230:Triazoles; C062942:2-phenyl-6-(2'-(4'-(ethoxycarbonyl)thiazolyl))thiazolo(3,2-b)(1,2,4)triazole; C072416:reverse transcriptase, Human immunodeficiency virus 2; D054303:HIV Reverse Transcriptase; D012194:RNA-Directed DNA Polymerase