Disorganization of MTs in PP4c^−/− MEF cells. (A) Expression of PP4c in PP4c^cko/cko and PP4c^−/− MEF cells. (left) Immunofluorescent staining was performed with an anti-PP4c antibody to assess the expression of PP4c 48 h after infection of adeno-Cre (representative of each genotype; n = 50). Uninfected PP4c^cko/cko MEF cells were used as controls. Arrowheads indicate centrosomal staining of PP4c. (right) Western blotting analysis of PP4c, PP4R1, and NDEL1 expression in PP4c^+/+, PP4c^cko/cko, and PP4c^−/− MEF cells. Representatives of three independent experiments are shown. (B) Severe MT disorganization in PP4c^−/− MEF cells. MEF cells for each genotype were stained with an anti–β-tubulin antibody 48 h after infection of adeno-Cre to PP4c^cko/cko MEF cells. PP4c^+/+ MEF cells infected with adeno-Cre were used for controls. MT patterns were categorized into four groups as indicated at the bottom of each panel. The relative proportions of each pattern are shown in the bottom panel (one example of three independent experiments; n = 100 for each genotype). (C) MTs in PP4c^−/− MEF cells were destabilized. Immunostaining was performed using antiacetylated tubulin 48 h after infection of PP4c^cko/cko MEF cells with adeno-Cre. PP4c^+/+ MEF cells infected with adeno-Cre were used for controls. MEF cells lacking PP4c revealed a clear reduction of acetylated tubulin (one example of three independent experiments; n = 60 for each genotype). Arrows indicate Cre-positive MEF cells. Bars, 10 μm.