p53 in stem cells

Figure 1 Differentiation of embryonic stem cells by p53. A: Treatment of embryonic stem cells (ESCs) with nutlin leads to p53 accumulation and transcriptional activation. Activated p53 stimulates transcription of p21, whose gene product initiates cell cycle arrest at the G1/S border and differentiation; B: Treatment of ESCs with retinoic acid (RA) leads to phosphorylation of p53 at serine 315 and repression of nanog followed by differentiation; C: Irradiation of ESCs with UV light or treatment with doxorubicin leads to activation of p53. Activated p53 represses transcription of nanog and oct4, resulting in the differentiation of ESCs.