HES1 cooperates with pRb to activate RUNX2-dependent transcription

The retinoblastoma protein, pRb, can activate the transcription factor RUNX2, an essential regulator of osteogenic differentiation, but the mechanism of this activation is unknown. Here we studied the interaction of pRb and RUNX2 with HES1, previously reported to augment RUNX2 activity. PRb can act to promote RUNX2/HEX1 association with concomitant promoter occupancy and transcriptional activation in bone cells.