Figure 4From: HIV relies on neddylation for ubiquitin ligase-mediated functionsNeddylation is important for Vpr mediated depletion of UNG2 through CRL4. HEK293T cells were either mock treated or treated with 250 nM MLN4924 for four hours and infected with VSV-G-pseudotyped-HIV-1 or -HIV-1 with a frame shift mutation in Vpr. Twenty-four hours after infection, cells were harvested and the lysates immunoblotted for endogenous UNG2, HIV-1 p24 and tubulin (A endog.). HEK293T cells were transfected with an expression vector for UNG2 with two HA epitope tags (UNG2–2HA). Forty-eight hours later, cultures were mock treated or treated with 250 nM MLN4924 for four hours and then infected with VSV-G-pseudotyped-HIV-1 or -HIV-1 with a frame shift mutation in Vpr. Twenty-four hours later, cells were lysed and immunoblotted for the HA epitope, HIV-1 p24, and tubulin (A exog.). HEK293T cells were treated for 2 hours with concentrations of MLN4924 as indicated and then either mock infected or infected, in parallel, with a reduced MOI (approximately 2) of VSV-G-pseudotyped HIV-1. The cells were harvested for immunoblotting 24 and 48 hrs after infection. Blots were probed for endogenous UNG2, CUL4A, tubulin or HIV-1 p24 (B). Twenty-four hours after transfection with UNG2–2HA expression vector, HEK293T cells were treated and infected as described for panel B. Forty-eight hours after infection, cultures were harvested for western blot analysis and probed for UNG2–2HA (HA), CUL4A, HIV-1 p24, or tubulin (C). HEK293T cells were transfected with UNG2–2HA expression vector and either an expression vector (pcDNA3.1(−)) or ones for DN UBC12 or DN CUL4A. Twenty-four hours later cultures were mock infected or infected with VSV-G-pseudotyped-HIV-1. Twenty-four hours after infection cultures were lysed for immunoblotting and probed for UNG2–2HA (HA), endogenous UNG2, CUL4A, DN CUL4A (HA), DN UBC12, HIV-1 p24, or tubulin (D).Back to article page