Figure 4
LMP1 expression induces cleavage of the MLL bcr. (A) Detection with anti-V5 antibody. SUNE1 cells were either transfected with vectors, pcDNA or pTracer (lanes 1 and 3); or LMP1 expression plasmids, pcDNA-LMP1 or pTracer-LMP1 (lanes 2 and 4). Cell lysate was analyzed on 10% SDS PAGE, and LMP1 expression was detected by anti-V5 antibody. (B) Detection with S12 anti-LMP1 antibody. SUNE1 cells were either transfected with vectors, pcDNA or pTracer (lanes 2 and 4); or LMP1 expression plasmids, pcDNA-LMP1 or pTracer-LMP1 (lanes 3 and 5). Cell lysate was analyzed on 10% SDS PAGE, and LMP1 expression was detected by S12 anti-LMP1 antibody. Lysate from the EBV-positive B95 cell line was included as positive control (lane 1). Arrows labeled 72 kDa and 63 kDa indicate the size of the expressed LMP1 (with V5 epitope and His-tag) and the endogenous LMP1 of B95-8 respectively. (C) Detection of MLL bcr cleavage by IPCR. SUNE1 cells transfected with vectors, pcDNA or pTracer (lanes 1 and 3); or LMP1 expression plasmids, pcDNA-LMP1 or pTracer-LMP1 (lanes 2 and 4) were collected for genomic DNA extraction. DNA was processed for nested IPCR as described in methods. Arrow labeled 2 kb indicates the position of the IPCR product of the intact MLL bcr. Arrows labeled 600 bp and 300 bp indicate the positions of the IPCR products of the cleaved MLL bcr. M1 and M2 represent the 1 kb and 100 bp DNA marker respectively.