Figure 8: Klf5 binding to its motifs of Dspp and Dmp1 regulatory regions in vivo.

(a) The diagram shows that six pairs of primers were designed to amplify the Klf5 binding sites in the first intron 1 of mouse Dspp gene from Dspp-site 1 to Dspp-site 9 in vivo for ChIP assay. The position number was stated as Dspp-primer 1: 50 bp to 257 bp; Dspp-primer 2: 1,219 bp to 1,422 bp; Dspp-primer 3: 1,885 bp to 2,074 bp; Dspp-primer 4: 2,177 bp to 2,468 bp; Dspp-primer 5: 2,574 bp to 2,861 bp; Dspp-primer 6: 3,025 bp to 3,265 bp. (b–g) ChIP assay showed that endogenous Klf 5 interacted with its motifs in the Dspp regulatory regions while Klf 5 overexpression significantly increased binding to its motifs in Dspp regulatory regions from Dspp site 1 to Dspp site 9 in vivo. (h). Two pairs of primers were used for the Klf5 binding sites in human Dmp1 promoter from Dmp1-site 1 to Dmp1-site 2 for ChIP assay. ChIP assay was performed with chromatin from iMDP-3 cells with transfection of Dspp-5.7 kb reporter construct (b–g) and Dmp1–2.6 kb promoter construct (i and j) with either pcDNA3-Klf5 or pcDNA3 plasmid. The results revealed that Klf5 binds to the Dspp regulatory regions encompassing the CACCC/GGGTG boxes between +73 to +2.8 kb and the Dmp1 promoter between −2.6 kb to −1,656 bp in vivo and exhibited an increasing transcription in Klf5-stimulated groups in iMDP-3 cells.