E4orf4 recruits Par3 to the nuclear lamina in tumorigenic cells. (A and B) Representative single-plane Airyscan confocal images of HaCaT (nontumorigenic) and U2OS cells (tumorigenic) showing endogenous Par3 (in green) and lamin A/C staining (in magenta). Graphs show the number of Par3 clusters per cell with a relative area ≥200 pixel units (p.u.); data represent means ± SEM (n = 19, 21, 32, and 31 cells, respectively). (C) Quantification of Par3 intensity profiles for the datasets represented in A and B showing the means (solid lines) and SEM (shaded areas; n = 20, 20, 19, and 22 cells), as measured along a 5 µm section that spanned the extracytoplasmic to the nuclear regions (dotted lines) by taking two measurements per cell; Cyto, cytoplasmic; Extra, extracellular. The intensity profiles of lamin A/C in E4orf4-expressing cells are shown as a reference. (D) Representative single-slice Airyscan confocal images of a nucleus from an E4orf4-expressing U2OS cell showing Par3 clusters (in green) decorating the center of a lamina groove delineated by lamin A/C staining (in magenta). (E) Quantification of Par3 intensity profiles compared with lamin A/C at lamina grooves for datasets represented in D showing average (solid line) and SEM (shaded area; n = 14 cells), as measured along a 3-µm section perpendicular to a lamina groove (dotted line in enlarged view). Bars: 10 µm. ****, P < 0.0001; ns, not significant.