Hsp72 knockdown decreases EBNALP coactivation with EBNA2 and CHIP inhibition of EBNA2 and EBNALP coactivation. (A) Lysates of BJAB cells and BJAB cell clones 2a and 2b, which are stably transfected with psiRNA-Hsp72, were immune blotted with rabbit antibody to Hsp72 and mouse monoclonal antibodies to Hsp90 or β-tubulin. (B-E) Hsp72.2a BJAB cells that are 50% Hsp72 deficient or Hsp72.2b BJAB cells that are 90% Hsp72 deficient were transfected with 10 μg E2, 0 or 10 μg FLP, 30 μg Flag-tagged CHIP (CHIP) expression vector, and appropriate amounts of control expression vector, 2 μg β-gal control plasmid, and 5 μg LMP1p-Luciferase or Cp-Luciferase reporter plasmids. Cells were assayed for Luciferase activity after 24 hours. EBNA2, EBNALP, and CHIP expression were monitored by immune blot with specific antibodies.