TY  - JOUR
A1  - Schneider, Anna
A1  - Corona, Angela
A1  - Spöring, Imke
A1  - Jordan, Mareike
A1  - Buchholz, Bernd
A1  - Maccioni, Elias
A1  - Di Santo, Roberto
A1  - Bodem, Jochen
A1  - Tramontano, Enzo
A1  - Wöhrl, Birgitta M.
T1  - Biochemical characterization of a multi-drug resistant HIV-1 subtype AG reverse transcriptase: antagonism of AZT discrimination and excision pathways and sensitivity to RNase H inhibitors
JF  - Nucleic Acids Research
N2  - We analyzed a multi-drug resistant (MR) HIV-1 reverse transcriptase (RT), subcloned from a patient-derived subtype CRF02_AG, harboring 45 amino acid exchanges, amongst them four thymidine analog mutations (TAMs) relevant for high-level AZT (azidothymidine) resistance by AZTMP excision (M41L, D67N, T215Y, K219E) as well as four substitutions of the AZTTP discrimination pathway (A62V, V75I, F116Y and Q151M). In addition, K65R, known to antagonize AZTMP excision in HIV-1 subtype B was present. Although MR-RT harbored the most significant amino acid exchanges T215Y and Q151M of each pathway, it exclusively used AZTTP discrimination, indicating that the two mechanisms are mutually exclusive and that the Q151M pathway is obviously preferred since it confers resistance to most nucleoside inhibitors. A derivative was created, additionally harboring the TAM K70R and the reversions M151Q as well as R65K since K65R antagonizes excision. MR-R65K-K70R-M151Q was competent of AZTMP excision, whereas other combinations thereof with only one or two exchanges still promoted discrimination. To tackle the multi-drug resistance problem, we tested if the MR-RTs could still be inhibited by RNase H inhibitors. All MR-RTs exhibited similar sensitivity toward RNase H inhibitors belonging to different inhibitor classes, indicating the importance of developing RNase H inhibitors further as anti-HIV drugs.
KW  - ribonuclease H
KW  - HIV-1 subtype AG
KW  - azidothymidine
KW  - reverse transcriptase
KW  - multi-drug resistance
Y1  - 2016
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-166423
VL  - 44
IS  - 5
ER  - 
TY  - JOUR
A1  - Hartl, Maximilian J.
A1  - Bodem, Jochen
A1  - Jochheim, Fabian
A1  - Rethwilm, Axel
A1  - Rösch, Paul
A1  - Wöhrl, Birgitta M.
T1  - Regulation of foamy virus protease activity by viral RNA
JF  - Retrovirology
N2  - No abstract available.
KW  - Virologie
Y1  - 2011
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-142248
VL  - 8
IS  - Suppl. 1
ER  - 
TY  - JOUR
A1  - Spannaus, Ralf
A1  - Hartl, Maximilian J.
A1  - Wöhrl, Birgitta M.
A1  - Rethwilm, Axel
A1  - Bodem, Jochen
T1  - The prototype foamy virus protease is active independently of the integrase domain
N2  - Background: Recently, contradictory results on foamy virus protease activity were published. While our own results indicated that protease activity is regulated by the viral RNA, others suggested that the integrase is involved in the regulation of the protease. Results: To solve this discrepancy we performed additional experiments showing that the protease-reverse transcriptase (PR-RT) exhibits protease activity in vitro and in vivo, which is independent of the integrase domain. In contrast, Pol incorporation, and therefore PR activity in the viral context, is dependent on the integrase domain. To further analyse the regulation of the protease, we incorporated Pol in viruses by expressing a GagPol fusion protein, which supported near wild-type like infectivity. A GagPR-RT fusion, lacking the integrase domain, also resulted in wild-type like Gag processing, indicating that the integrase is dispensable for viral Gag maturation. Furthermore, we demonstrate with a trans-complementation assays that the PR in the context of the PR-RT protein supports in trans both, viral maturation and infectivity. Conclusion: We provide evidence that the FV integrase is required for Pol encapsidation and that the FV PR activity is integrase independent. We show that an active PR can be encapsidated in trans as a GagPR-RT fusion protein.
KW  - Medizin
KW  - Foamy virus
KW  - Regulation of protease activity
KW  - PARM
KW  - Integrase
KW  - GagPol fusion protein
Y1  - 2012
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-75370
ER  -