FIG. 5.

Ser-22 and Ser-392 of lamin A are important for the redistribution of nuclear lamin induced by EBV reactivation. (A) EBV-positive NA or EBV-negative TW01 cells were left untreated or were treated with TPA/SB for EBV reactivation. At 48 h postinduction, cells were fixed and stained for lamin A/C to indicate nuclear lamina, BGLF4, and cellular DNA as described in Materials and Methods. Redistributed nuclear lamin and condensed cellular chromatin were observed in reactivated NA cells with BGLF4 expression but not in TPA/SB-treated TW01 cells. (B) NA cells were transfected with GFP-lamin A(WT) together with siBGLF4-1, siBGLF4-2, or a control siRNA (siCtrl). At 12 h posttransfection, cells were treated with TPA/SB for EBV reactivation. At 48 h posttreatment, cells were harvested for immunoblot analysis. The blots were probed with anti-BMRF1 48180 (Capricorn), anti-GFP JL-8, anti-Rta 467, anti-Zta 4F10, or anti-BGLF4 2616 in immunoblotting. GAPDH served as a loading control. (C) Slide-cultured NA cells under treatment similar to that for panel B were fixed and stained for BGLF4 (rabbit antiserum) and BMRF1 (88A9). (D) NA cells were transfected with GFP-lamin A(WT)-, GFP-lamin A(S22/392A)-, or GFP-lamin A(4A)-expressing plasmids. At 4 h posttransfection, cells were left untreated or were treated with TPA/SB to induce EBV reactivation. At 48 h posttreatment, cells were fixed and stained for BGLF4 to indicate EBV reactivation. EBV reactivation induces the disassembly of the nuclear rim and internalization in cells expressing GFP-lamin A but not in cells expressing the GFP-lamin A(S22/392A) or GFP-lamin A(4A) mutant. α-Lamin A/C, anti-lamin A/C antibody; α-BGLF4, anti-BGLF4 antibody; α-BMRF1, anti-BMRF1 antibody.