Fig. 6

STAT5b enhances the MKL-1-SRF interaction and induces MKL-1 to binding CArG box of Foxp3. a and b CD3⁺T cells were transiently transfected with a MKL-1, siSTAT5b, STAT5b, MKL-1 /siSTAT5b or MKL-1 /STAT5b or a control vector (pCDNA3.1) 48 h, and ChIP assays were performed by PCR with primers associated with the genes for Foxp3 as described in Materials and Methods. Sheared DNA/protein complexes were immunoprecipitated by using an anti-Myc-MKL-1 Ab. Then, PCR was carried out to detect the endogenous CArG regions in immunoprecipitated chromatin fragments. The amount of DNA in each sample (2% input) is shown at the second land. Immunoprecipitations were performed without primary antibody (No Ab) as a control and IgG as a negative control (**p<0.01) n = 3; c Cells were transfected with Myc-MKL-1 and HA-SRF along with NR or STAT5b siRNA. Association of MKL-1 and SRF was analyzed by coimmunoprecipitation. STAT5b silencing was detected from whole cell lysates (WCL). Controls for the immunoprecipitation were reaction without antibody (No Ab) or Myc transfection (No Tx); d Densitometric analysis of three experiments is shown; e Myc-MKL-1 and HA-SRF were cotransfected with empty vector or STAT5b then treated IL-2. Coimmunoprecipitation shows IL-2 increased association of STAT5b to MKL-1 compared with DMSO. f Densitometric analysis of three experiments is shown