Fig. 4.
Role of the nuclear lamina and LINC complexes on the presence, organization, and nuclear shaping function of the perinuclear actin cap (A and B). (A) Representative top confocal cross-section showing the organization of the actin cap in a Lmna−/− MEF plated on a 10-μm wide FN micropattern. (B) Averaged nuclear shape factor of MEFs lacking lamin A/C (Lmna−/−) and WT cells as a function of FN micropattern width. Statistical significance is denoted with stars as in Fig. 1. (C) Proportion of WT MEFs and Lmna−/− MEFs showing an organized, disorganized, or no actin cap on unpatterned FN-coated surfaces. (D) Representative basal and apical organization of the actin network in an MEF transfected with EGFP-KASH2 and placed on an unpatterned FN-coated surface. The yellow and white arrowheads indicate the absence of an actin cap in an EGFP-KASH-transfected cell and presence of on actin cap in a control untransfected cell. (Scale bar, 10 μm.) (E) Averaged nuclear shape factor of WT MEFS (black) and MEFs transfected with either EGFP-KASH2 (red) or EGFP-KASH2ext (blue) as a function of micropattern width. (F) Proportion of WT MEFS and MEFs transfected with either EGFP-KASH2 or EGFP-KASH2ext showing an organized, disorganized, or no actin cap on unpatterned FN-coated surfaces. (G) Proportion of WT mouse adult fibroblasts (MAFs) and LmnaL530P/L530P MAFs on unpatterned FN surfaces showing either an organized, a disorganized, or no actin cap on unpatterned FN-coated surfaces.