Difference of lamin isoforms in the structure and the accumulation kinetics at sites of NE rupture induced by laser microirradiation. (A) Protein architecture of lamin isoforms. The coiled-coil central rod domain (gray), the NLS (yellow), the β-strands comprising the Ig-fold (blue or green), and the CaaX motif box (red) are shown. (B) A 405-nm laser is used to induce NE rupture at a precise location on the NL. (C–F) A 2-μm diameter spot at the NE in MEFs was laser-microirradiated to induce NE rupture, fixed within 10 min (C and D) or 60–70 min after laser microirradiation (E and F), and then stained with a combination of anti-mouse and anti-rabbit antibodies, followed with Alexa Fluor 488-labeled anti-mouse or rabbit IgG and Cy5-labeled anti-rabbit or mouse IgG, and Hoechst 33342 for DNA. At least two independent experiments were performed. (C and E) Representative images of single confocal sections. Magnified views of the indicated areas by orange boxes are shown (the second to fifth columns). Color-merged images (the first and second columns) show anti-LC (321, green)/anti-LA (4A58, magenta), anti-LB2 (EPR9701(B), green)/anti-LB1 (B-10, magenta), and NPC (mAb414, green)/anti-LA (323, magenta). The ruptured sites are indicated with yellow arrowheads (the second columns). Bars: 5 μm (the first column) and 2 μm (the second to fifth columns). (D and F) Ratios of cells with (green) and without (gray) enrichments of the indicated antibodies at the rupture sites. The numbers of analyzed cells are indicated in the bar charts.