Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.7.7.49 (reverse transcriptase)
 31,746 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Upon prolonged treatment with various antiretroviral nucleoside analogs such as 3'-azido-3'-deoxythymidine, 2',3'-dideoxyinosine, 2',3'-dideoxycytidine, (-)- beta-L-2', 3'dideoxy-3'thiacytidine and 2',3'-didehydro-3'-deoxythymidine, selection of human immunodeficiency virus type 1 (HIV-1) strains with mutations in the reverse transcriptase (RT) gene has been reported. We designed a reverse hybridization line probe assay (LiPA) for the rapid and simultaneous characterization of the following variations in the RT gene: M41 or L41; T69, N69, A69, or D69; K70 or R70; L74 or V74; V75 or T75; M184, I184, or V184; T215, Y215, or F215; and K219, Q219, or E219. Nucleotide polymorphisms for codon L41 (TTG or CTG), T69 (ACT or ACA), V75 (GTA or GTG), T215 (ACC or ACT), and Y215 (TAC or TAT) could be detected. In addition to the codons mentioned above, several third-letter polymorphisms in the direct vicinity of the target codons (E40, E42, K43, K73, D76, Q182, Y183, D185, G213, F214, and L214) were found, and specific probes were selected. In total, 48 probes were designed and applied to the LiPA test strips and optimized with a well-characterized and representative reference panel. Plasma samples from 358 HIV-infected patients were analyzed with all 48 probes. The amino acid profiles could be deduced by LiPA hybridization in an average of 92.7% of the samples for each individual codon. When combined with changes in viral load and CD4+ T-cell count, this LiPA approach proved to be useful in studying genetic resistance in follow-up samples from antiretroviral agent-treated HIV-1-infected individuals.
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PMID:Line probe assay for rapid detection of drug-selected mutations in the human immunodeficiency virus type 1 reverse transcriptase gene. 902 Nov 81

We investigated HIV-1 reverse transcriptase (RT) polymorphisms of plasma isolates from 98 HIV-1-infected study subjects with >2 years of antiretroviral therapy who were failing their current protease inhibitor (PI)-containing regimen. In 1 patient, we detected a virus with a heavily mutated beta3-beta4 connecting loop of the HIV-1 RT fingers subdomain, consisting of a single aspartate codon insertion between positions 69 and 70 and five additional variations: 64N, K65, K66, 67G, 68Y, T69, Ins D, 70R, W71, R72, K73, 74I. Mutants with the recently described 2-aa insertions between codons 68 and 70 of RT were detected in another 3 patients. Among the four isolates with the 1- or 2-aa insertions, the novel genotype was the most refractory to therapy and displayed the highest level of phenotypic resistance to nucleoside reverse transcriptase inhibitors (NRTIs). Follow-up samples demonstrated that the novel mutant represents a stable genetic rearrangement and that the amino acid insertions can coexist with nonnucleoside analogue reverse transcriptase inhibitors (NNRTI) mutations resulting in phenotypic resistance to both NRTIs and NNRTIs. An increasing number of HIV-1 isolates containing various insertions in the beta3-beta4 hairpin of the HIV-1 RT fingers subdomain appear to emerge after prolonged therapy with different NRTIs, and these polymorphisms can confer multiple drug resistance against NRTIs.
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PMID:A novel genotype encoding a single amino acid insertion and five other substitutions between residues 64 and 74 of the HIV-1 reverse transcriptase confers high-level cross-resistance to nucleoside reverse transcriptase inhibitors. Abacavir CNA2007 International Study Group. 1084 27