FIG 3.

The SLSATGR sequence in the lamin B2 tail domain maintains nuclear morphology. (A) Immunofluorescence staining of lamin B1, showing the nuclear morphology in control and lamin B2-depleted cells overexpressing full-length lamin B2-GFP (+LMNB2), (ii) lamin B2ΔHead (+ΔHead), and (iii) lamin B2ΔSLS (+ΔSLS) constructs. Control cells show ellipsoidal nuclei with uniform lamin B1 staining at the nuclear periphery. Lamin B2-depleted cells show nuclear blebs that partially stain for lamin B1 (arrowhead). Scale bars, ∼5 μm. (B) The incidence of nuclear blebs in lamin B2 depleted cells was reduced upon overexpression of full-length lamin B2 (siLMNB2+LMNB2) and lamin B2ΔHead (siLMNB2+ΔHead) but not upon overexpression of lamin B2ΔSLS (siLMNB2+ΔSLS). (*, P < 0.05; **, P < 0.01; ***, P < 0.001 [by Student's t test]) (number of independent biological replicates [N] = 3; n, number of nuclei). Error bars indicate SEM.