Membrane–chromatin tethering function of Lap2β in NE formation. (A) Map of Lap2β shows distinct functional domains that interact with DNA, BAF (LEM), lamins, and lipid bilayer (TM). (B) Representative traces of chromatin-localized GFP-NLS in which t = 0 is set at the onset of chromosome separation show the time required for NE formation in U2OS cells where fragments of Lap2β, DNA, LEM, DNA + LEM, or LMN + lipid bilayer have been overexpressed. (C) NE formation time was measured with the expression of Lap2β fragments. n > 40 for each fragment. P < 0.001 for the expression of DNA, LEM, and DNA + LEM fragments when compared with control cells; P = 0.4 for LMN + TM. Dotted line indicates control cell timing. Error bars indicate SEM. (D) U2OS cells were transfected with the V5-DNA + LEM fragment of Lap2β and stained with antibodies against V5 (red) and endogenous (endo) Lap2β (green). Arrowheads indicate early G1 cells as indicated by nuclear size and paired orientation. (E) U2OS cells were transfected with the DNA + LEM fragment of Lap2β and stained with antibodies against endogenous Lap2β and LBR. Arrowheads indicate cells where endogenous Lap2β, but not LBR, is displaced by the chromatin-binding domain of Lap2β. Bars, 20 µm.