Poly (ADP-ribose) polymerase is involved in PMA-induced activation of HIV-1 in U1 cells by modulating the LTR function.
Phorbol 12-myristate 13-acetate (PMA)-induced HIV-1 production in U1 cells was markedly suppressed by inhibitors of poly (ADP-ribose) polymerase (PARP). Northern blot analysis revealed that the PARP-inhibitors suppressed the virus production at a level of transcription. In order to examine the effect of PARP on transcriptional regulation of HIV-1 genes, we transfected a reporter plasmid containing HIV-1-LTR-promoted luciferase gene to L-1210 cell clones, which expressed varying decreased level of PARP. In wild type L-1210 cells, the expression of LTR-promoted luciferase gene was stimulated approximately 4-fold in response to PMA, whereas the PMA-dependent response was almost abolished in mutant cells, which expressed only 8% of PARP of the wild type cells. The effect of decrease in PARP content on the function of HIV-1-LTR was confirmed also in human wild type cells, Jurkat and J111, which were co-transfected with the reporter plasmid and a plasmid expressing a PARP-antisense RNA: Down-regulation of PARP in the cells by the expression of the antisense RNA significantly suppressed the PMA-dependent, LTR-function of the reporter plasmid in both Jurkat and J111 cells. NF-kappaB, which is known to mediate the PMA-induced activation of HIV-1 in U1 cells, was found to be activated approximately 5-fold in PMA-treated U1 cells. PARP-inhibitor, unexpectedly, did not suppress but rather stimulated (approximately 2-fold) the NF-kappaB activation. Combining the results with the finding that the LTR-function was minimum in a PARP-defective mutant cells in spite of a very high level of the activated NF-kappaB in the cells, we suggest that PARP, in addition to activated NF-kappaB, is essential for the function of HIV-1 LTR.
Kameoka
M
M
Department of Biochemistry, Nara Medical University, Kashihara, 634-8521, Japan.
Tanaka
Y
Y
Ota
K
K
Itaya
A
A
Yoshihara
K
K
D002460:Cell Line; D004247:DNA / Q000235:genetics / Q000378:metabolism; D015967:Gene Expression Regulation, Viral / Q000187:drug effects*; D017930:Genes, Reporter / Q000235:genetics; D016325:HIV Long Terminal Repeat / Q000235:genetics*; D015497:HIV-1 / Q000187:drug effects / Q000235:genetics* / Q000502:physiology; D006801:Humans; D009154:Mutation; D016328:NF-kappa B / Q000378:metabolism; D000067856:Poly(ADP-ribose) Polymerase Inhibitors; D011065:Poly(ADP-ribose) Polymerases / Q000235:genetics / Q000378:metabolism*; D011401:Promoter Regions, Genetic / Q000235:genetics*; D016372:RNA, Antisense / Q000235:genetics; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D012367:RNA, Viral / Q000096:biosynthesis / Q000235:genetics; D013755:Tetradecanoylphorbol Acetate / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D014162:Transfection; D014407:Tumor Cells, Cultured; D014779:Virus Replication / Q000187:drug effects
D016328:NF-kappa B; D000067856:Poly(ADP-ribose) Polymerase Inhibitors; D016372:RNA, Antisense; D012333:RNA, Messenger; D012367:RNA, Viral; D004247:DNA; D011065:Poly(ADP-ribose) Polymerases; D013755:Tetradecanoylphorbol Acetate