FIGURE 3.

Three fragments of siRNA against rat SIRT2 (rSIRT2) mRNA were examined for efficiency of SIRT2 knock‐down. All fragments have an effective suppression in SIRT2 expression with siRNA‐3 being most effective (A; left panel). The corresponding sequence against human SIRT2 (hSIRT2) mRNA, derived from the siRNA‐3 and named siRNA‐III, was tested in Jurkat cells for SIRT2 knock‐down efficiency (A; right panel). Subsequently, both siRNA‐3 and siRNA‐III were used to construct lentiviral vectors. Viral particles for rSIRT2 overexpression (LV5 vector) and rSIRT2 knock‐down (pGLV3/H1/GFP + Puro vector) were infected into B104 cells with high efficiency (B). Co‐IP with anti‐Hsp90 in B104 cells overexpressing rSIRT2 (+) showed a decrease in the acetylation levels in the protein band corresponding to Hsp90 compared with control cells (WT) (C), whereas SIRT2 knock‐down ³⁶ showed an increase in the acetylation levels of the protein band corresponding to Hsp90 compared with control cells (WT) (D). Taken together, these results suggest that Hsp90 is a direct target of SIRT2 deacetylation. Hsp90 co‐IPs (C and D) were repeated three separate times, and a representative immunoblots are shown