Cyclophilin B interacts with Bip and Grp94. (A) GST pull-down assay. A GST pull-down assay was conducted using bacterially expressed recombinant GST-CypB/wt and GST-CypB/R62A fusion proteins and H2C2 cell extracts treated with or without Tg and Tm. Western blotting was conducted using Bip, Grp94, CypB or GST antibodies. GST alone was used as a negative control. (B) Co-immunoprecipitation of CypB with Bip and Grp94. Immunoprecipitation was conducted with non-immune serum (Non-IS) or anti-CypB antibody (CypB-Ab). (C)Yeast two-hybrid binding assays. pGBKT7, pGADT7, pGBKT7/CypB/wt, pGBKT7/CypB /R62A, pGADT7/Grp78 and pGADT7/Grp94 were used in the yeast two-hybrid assay with AH109. In the left panel, CypB/wt interacts with Bip or Grp94. In the right panel, CypB/R62A also interacts with Bip or Grp94.