FIGURE 1:

Depletion of CCTε by siRNA increases serum response factor activity. (A) SiRNA targeting of a single CCT subunit leads to disassembly of the CCT oligomer and an excess of the nontargeted subunits as free monomers. For simplicity, only the CCT subunits in one ring of the oligomer are labeled. (B) MDA-MB-436 cells were treated with siRNAs targeting each CCT subunit or an Oligofectamine control and an SRF-luciferase reporter gene system used to assess SRF activation after 16 h in 10% serum. Results shown are the mean ± SEM from three experiments. Student's t test was performed for each siRNA compared with control. (C) Western blot analysis of CCT subunit levels after siRNA depletion in cell lysates standardized by cell counting. Antibodies are affinity-purified rabbit polyclonal antibodies to CCTγ and CCTε and rat monoclonal antibodies η81a against CCTη and δ8g against CCTδ.