Regulatory motifs for c-mpl gene expression induced by PMA

Objectives: To further investigate the role of PKC in c-mpl gene expression, we examined the effect of phorbol 12-myristate 13-acetate(PMA) on c-mpl promoter activity to explore the motif required for c-mpl gene expression in CMK cells.

Methods: We examined the effect of PMA on c-mpl promoter activity by using transient transfection assay system. Besides pGL3-c-mpl(-121), we also examined the influence of the deletion constructs and site-directed mutagenesis on c-mpl promoter activity induced by PMA.

Results: The promoter activity of c-mpl was dramatically increased by PMA, on the other hand, PKC inhibitors(GF109303X, H7 and CalphostinC) significantly inhibited the PMA-induced increase of c-mpl promoter activity. In case of the deletion constructs, the activity was clearly reduced from pGL3-c-mpl (-83). As to site-directed mutagenesis, we confirmed the positive regulatory elements involved in c-mpl gene expression induced by PMA.

Conclusions: Our data strongly suggest that PKC plays the principal role in maintaining c-mpl transcription and also we elucidated the crucial elements involved in PMA-induced c-mpl gene expression in CMK cells.

*This study was partially supported by the Grant-in-Aid for Encouragement of Young Scientists (No.13771085) from Japan Society for the Promotion of Science(JSPS).