PKG1β activates expression from the HIV-1 LTR. A) Activation of HIV-1 LTR luciferase by PKG1β. HeLa cells were cultured in medium with 0.1% fetal bovine serum and transfected as indicated with HIV-1 LTR luciferase reporter plasmid in the absence and presence of Tat, and with a PKG1-β expression plasmids. PKG1β was found to increase Tat dependent transcriptional activity of the HIV-1 LTR by four fold. B) Co-transfection of PKG1β and HIV-1 infectious molecular clone, pNL4-3, resulted in dose dependent increase in viral protein expression. Expression of FLAG-tagged transfected PKG1β (top panel) and HIV-1 viral proteins are shown by Western blotting.