Functional analysis of the transcriptional coactivators p300 and CBP using ribozyme.

p300 and CERB binding protein (CBP) are transcriptional coactivator which participate many signal transduction pathways via interaction with DNA binding proteins. In this study, we investigated functions of p300 and CBP during the retinoic acid (RA) induced F9 cell differentiation using hammerhead ribozymes. In wild type F9 cells, induction of c-jun gene was observed at 18 h after treatment with RA. Interestingly, RA-dependent expression of c-jun gene was not induced in cells expressing the p300-directed ribozyme. By contrast, the CBP-directed ribozyme did not affect expression of the c-jun gene. These results suggest that p300 is critical for the induction of c-jun gene during RA-induced differentiation.