Figure 3.

EBNA1 induces decondensation of the LacO chromatin array. (a) A03-1 cells were transfected with mCherry-LacR, or mCherry-LacR fused to either EBNA1 or the herpes simplex-1 trans-activator VP16. The condensed array appears as a compact dot in cells expressing mCherry-LacR. Tethering of either EBNA1 or VP16 to the array induced the formation of extended structures of irregular shape. Scale bar 5 µm. (b) Quantification of the array size expressed as the percentage of nuclear area occupied by the array. EBNA1 and VP16 induced a comparable 4-fold increase in the size of the array. LacR = 2.9 ± 0.2; LacR-EBNA1 = 11.7 ± 0.9; LacR-VP16 = 11.3 ± 1.8, ***P < 0.0001.