HIV-1 Tat protein exerts no significant effect on the RNA interference machinery.
(a) Nuclear localization of Tat C protein in CHME3 cells exposed to recombinant HIV-1 Tat C protein. CHME3 cells were treated with Tat C protein at 5 μg per ml of culture media for 24 hours. Cells were then washed with PBS, fixed and stained with anti-Tat antibody, and visualized with Alexa 488-conjugated fluorescent antibody. (b) Western blot analysis for Dicer and Drosha in CHME 3 cells exposed to Tat C for 24 hours showed no significant change in the expression of either protein. β-tubulin was used as loading control for normalizing the image density. (c) Densitometry quantification for Drosha and Dicer enzyme normalized to β-tubulin. All experiments were performed three times, and data are presented as mean ± SE.