Nuclear Factor 90(NF90) targeted to TAR RNA inhibits transcriptional activation of HIV-1.
BACKGROUND
Examination of host cell-based inhibitors of HIV-1 transcription may be important for attenuating viral replication. We describe properties of a cellular double-stranded RNA binding protein with intrinsic affinity for HIV-1 TAR RNA that interferes with Tat/TAR interaction and inhibits viral gene expression.


RESULTS
Utilizing TAR affinity fractionation, North-Western blotting, and mobility-shift assays, we show that the C-terminal variant of nuclear factor 90 (NF90ctv) with strong affinity for the TAR RNA, competes with Tat/TAR interaction in vitro. Analysis of the effect of NF90ctv-TAR RNA interaction in vivo showed significant inhibition of Tat-transactivation of HIV-1 LTR in cells expressing NF90ctv, as well as changes in histone H3 lysine-4 and lysine-9 methylation of HIV chromatin that are consistent with the epigenetic changes in transcriptionally repressed gene.


CONCLUSIONS
Structural integrity of the TAR element is crucial in HIV-1 gene expression. Our results show that perturbation Tat/TAR RNA interaction by the dsRNA binding protein is sufficient to inhibit transcriptional activation of HIV-1.
Agbottah
Emmanuel T
ET
Department of Biochemistry & Molecular Biology, School of Medicine, The George Washington University, Washington, DC, USA. bcmeta@gwumc.edu
Traviss
Christine
C
McArdle
James
J
Karki
Sambhav
S
St Laurent
Georges C
GC
Kumar
Ajit
A
D001665:Binding Sites; D002458:Cell Fractionation; D002460:Cell Line; D024202:Electrophoretic Mobility Shift Assay; D015696:Gene Products, tat / Q000037:antagonists & inhibitors* / Q000378:metabolism; D016325:HIV Long Terminal Repeat; D015497:HIV-1 / Q000276:immunology*; D006367:HeLa Cells; D006657:Histones / Q000378:metabolism; D006801:Humans; D019169:Jurkat Cells; D008745:Methylation; D050779:Nuclear Factor 90 Proteins / Q000502:physiology*; D011485:Protein Binding; D012330:RNA, Double-Stranded / Q000378:metabolism; D012367:RNA, Viral / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000502:physiology; D015533:Transcriptional Activation; D054322:tat Gene Products, Human Immunodeficiency Virus
D015696:Gene Products, tat; D006657:Histones; D050779:Nuclear Factor 90 Proteins; D012330:RNA, Double-Stranded; D012367:RNA, Viral; D016601:RNA-Binding Proteins; D054322:tat Gene Products, Human Immunodeficiency Virus