Figure 2. PERK knockdown triggers a G2/M delay.
(A) MDA-MB468 cells were infected with control shRNA or anti-PERK shRNA for the indicated intervals. Cells were pulsed with BrdU 45 min prior to harvest for FACS analysis. (B) Kinetics of growth of the MDA-MB468 parental cell line, control shRNA-(shControl) or shPERK-transduced cells (shPERK), and shPERK-transduced cells reconstituted with mouse Myc-PERK (+mPERK). PERK protein levels following expression of shRNA targeting human PERK and reconstitution with mouse Myc-PERK are shown. (C) Proliferation rates in mammary gland sections from control (PERKloxP/loxP) and mammary gland-specific PERK knockout mice (PERKΔ/Δ) on pregnancy day 16 (P16) and lactation day 3 (L3) were determined by immunohistochemistry for BrdU (animals were injected with BrdU 1 h prior to being euthanized). (D) Quantification of BrdU-positive cells from (C) is shown; error bars indicate S.D. among 3 animals, 5 acini were counted per animal.