FIGURE 2.

Requirement of a functional Hsp90 machinery for hGTSE-1 mediated-p21 stabilization. A, U2OS cells were transfected with vectors encoding p21 with an empty vector or with hGTSE-1 for 24 h. A vector encoding GFP-tagged histone H2B (GFP-H2B) was used as transfection efficiency control. B, U2OS cells were transfected as in A and after 6 h were treated with 17-AAG for 16 h. C, JPIC/U cells were treated with the indicated doses of 17-AAG alone (−) or together with ponasterone A (pon A; +) for 16 h. D, JPIC/U cells were transfected with control (siCONT) or WISp39 (siWISp39) siRNAs for 72 h followed by the addition (+) or not (−) of ponasterone A for the last 16 h. Immunoblot analyses were performed using antibodies against hGTSE-1, p21, GFP, and actin as loading control.