Abstract: Objective To construct a luciferase reporter vector containing the response element of transcription protein AP2α for
screening the effect of bone morphogenetic proteins (BMPs) on the transcriptional activity of AP2α. Methods Four
tandem-linked response elements of AP2α were cloned to the pBGLuc luciferase reporter gene plasmid, which was digested
with Bam HI and Mlu I to construct pBGLuc-AP2α-RE vector. The recombinant adenovirus Ad-AP2α and its dominant
negative mutant Ad-dnAP2α were used to infect mouse mesenchymal stem cells C3H10; the changes in cellular AP2α mRNA
and protein expressions were detected by real-time PCR and Western blotting, and electrophoretic mobility shift assay (EMSA)
was carried out to assess the DNA-binding ability of AP2α. C3H10 cells were transfected with pBGLuc-AP2α-RE vector, and
AP2α transcriptional activity was measured using luciferase reporter gene assay. In pBGLuc-AP2α-RE vector-transfected
C3H10 cells infected with Ad-BMPs, luciferase reporter gene assay was performed to screen the effect of BMPs on AP2α
transcriptional activity. Results The results of PCR, enzyme digestion and sequencing all confirmed correct cloning of
AP2α-RE into pBGLuc-AP2α-RE luciferase reporter vector, and Ad-AP2α infection significantly increased AP2α expression
and its DNA binding ability. The dominant negative mutants expressed the corresponding mutants, and EMSA results showed
that Ad-dnAP2α-△bHLH significantly lowered while Ad-dnAP2α-△TAD enhanced the DNA-binding ability of AP2α. AP2α
over-expression promoted AP2α transcriptional activity, which was suppressed by the two dominant negative mutants. AP2α
transcriptional activity increased in the cells infected with the recombinant adenovirus BMPs, especially in cells with BMP9
infection. Conclusions The luciferase reporter vector containing the response element of AP2α we constructed allows detection
of AP2α transcriptional activity. BMP9 can significantly enhance AP2α transcriptional activity.