FIGURE 5.

MPA treatment induces G₁ cell cycle arrest that requires the ribosomal proteins L5 and L11. U2OS cells were transfected with scrambled, L5, or L11 siRNA followed by treatment with methanol or 10 μmol/liter MPA for 12 h before harvesting as indicated. The cells were then stained with PI followed by flow cytometry analysis for cell cycle profile. The histograms of PI staining from one representative experiment are shown in A. The mean percentages of cells in G₁ or G₂/M phase are shown in B.