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Figure 1 | Biology Direct

Figure 1

From: 14-3-3 theta binding to cell cycle regulatory factors is enhanced by HIV-1 Vpr

Figure 1

Decreased expression of 14-3-3 θ, β, γ, and Chk1 protects against Vprv- and HIV-1 (vif-)-induced cell cycle arrest. (A) Diagram of the basic HIV-1 genomes used throughout the study. Env-deficient NL4-3, NL4-3e-n-GFP, (top) also lacks nef, which was replaced with EGFP. Vpr protein associated with virions (Vprv) was delivered into cells using an RT point mutant, D186N, derivative of NL4-3e-n-GFP (bottom). (B) Jurkat T cells were transfected with 500 pmol of nonspecific (ns), 14-3-3 θ, or Chk1 siRNA and four days later mock-infected or infected with either NL4-3e-n-GFP (NL4-3), NL4-3e-n-GFP Vif- (NL4-3 vif-), or RT- NL4-3e-n-GFP (Vprv). Cell cycle arrest by was measured by flow cytometric detection of DRAQ5 DNA staining 44 hours post-infection. DNA analysis of cultures infected with RT+ NL4-3e-n-GFP was restricted to actively infected GFP+ cells. Data is representative of six independent experiments. (C) The Dean-Jett-Fox cell cycle model was used for determination of G1 and G2,M populations and the ratio is plotted for the FACS data in (B). The transfected siRNA is indicated in the legend. (D) Western blot detection of 14-3-3 θ and Chk1 expression four days post-transfection for the samples in (B) and (C). β-actin was probed as a loading control. (E) Live cell counts were measured for mock-infected and Vprv-infected samples in (B-D) at the indicated times after infection by flow cytometric constant time acquisition. (F) Jurkat cells were transfected as in (B) with the addition of a co-transfected sample that received both 14-3-3 θ and Chk1 siRNA (θ + Chk1). Western blot analysis of 14-3-3 θ, Chk1, and β-actin, as a loading control, is shown. (G) Cell cycle analysis as in (C) for the samples in (F).

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