PKF050-638 inhibits the CRM1-mediated Rev nuclear export by disrupting CRM1-NES interaction. PKF050-638 is an effective and selective inhibitor of HIV-1 Rev (IC50=0.04 μM).

HIV-1 Rev:0.04 μM

PKF050-638 (7.5 μM; 1 hour) is interfering with the CRM1-mediated nuclear export machinery. HeLa cells are cotransfected with the BFP-tagged Rev protein and the GFP-tagged hCRM1. Upon treatment with PKF050-638, this Rev-dependent hCRM1 nucleolar localization is abolished after 60 min, and PKF050-638 does not affect the Rev nucleolar distribution. PKF050-638 (7.5 μM; 4 hours) restores the inhibition of export in pRev14-GFP-transfected cells. In cells incubated with PKF050-638, most of the Rev14-GFP is localized in the nucleus and nucleolus. Whereas in untreated cells, Rev14-GFP is still in the cytoplasm. This result displays that the majority of PKF050-638-treated cells are able to reverse completely the inhibitory effects of the agent. PKF050-638 (5 μM; 2 hours) inhibits nuclear export of rev, in addition, the Rev14-GFP mutant accumulates in the nucleus indicating that the NES of Rev is a part of Rev required for export inhibition by PKF050-638 [1].