p53 Transactivation and protein accumulation are independently regulated by UV light in different phases of the cell cycle

Tarja Haapajärvi, Kimmo Pitkänen, Minna Tsubari, Marikki Laiho

Research output: Contribution to journalArticlepeer-review

Abstract

DNA damage-induced activation of the p53 suppressor gene is suggested to be central in the cellular damage response pathway. In this study, we analyzed the responses of p53 to UVC radiation in synchronized mouse fibroblasts in terms of p53 accumulation, transcriptional activation, and sequence-specific DNA-binding activity. UVC was found to induce accumulation of p53 cell cycle dependently in G1/S- and S-phase cells but not in G0 or G1 cells. In contrast, p53 transcriptional activity and its target genes, p21 and GADD45, were stimulated by UVC in G0 and G1 cells in the absence of detectable p53 protein. The accumulation of p53 and increased p21 and GADD45 expression were replication dependent in S-phase cells. Interestingly, sequence-specific p53 DNA-binding activity was stimulated also replication independently in S phase, though the effect was and conveyed to stimulation of p53 target genes, suggesting that additional events are required for p53- stimulated gene expression. The results show that opposed to the cell cycle dependence of p53 accumulation, the UVC-mediated transactivation by p53 is independent of the cell cycle phase and protein stabilization.

Original languageEnglish (US)
Pages (from-to)3074-3080
Number of pages7
JournalMolecular and cellular biology
Volume17
Issue number6
DOIs
StatePublished - Jun 1997

ASJC Scopus subject areas

  • Molecular Biology
  • Cell Biology

Fingerprint Dive into the research topics of 'p53 Transactivation and protein accumulation are independently regulated by UV light in different phases of the cell cycle'. Together they form a unique fingerprint.

Cite this