p21 regulates the cell cycle…or the other way around?

JULIANA SPERONI; VANESA GOTTIFREDI

CELL CYCLE

LANDES BIOSCIENCE

Lugar: Austin, Texas; Año: 2011 vol. 10 p. 3430 - 3431

1538-4101

A novel signalling loop after gIR? While high p21 levels prevent S-phase entrance, p21 does not accumulate in cells transiting S phase. p53 transcriptionally activates p21 and promotes its accumulation in G1, but Hdm2- and Cul4 (Cdt2)-mediated p21degradation might prevent its upregulation in S phase. p21 degradation might be required to maintain the processivity of DNA replication at sites where damaged DNA must be used as templates.1 Also, the resolution of double-strand breaks caused by gIR might also benefit from the duplication of the DNA around lesions that might promote error-free repair by homologous recombination. Thus, once started, S phase-driven p21 downregulation might facilitate the cell survival associated with the complete finalization of DNA duplicationgIR? While high p21 levels prevent S-phase entrance, p21 does not accumulate in cells transiting S phase. p53 transcriptionally activates p21 and promotes its accumulation in G1, but Hdm2- and Cul4 (Cdt2)-mediated p21degradation might prevent its upregulation in S phase. p21 degradation might be required to maintain the processivity of DNA replication at sites where damaged DNA must be used as templates.1 Also, the resolution of double-strand breaks caused by gIR might also benefit from the duplication of the DNA around lesions that might promote error-free repair by homologous recombination. Thus, once started, S phase-driven p21 downregulation might facilitate the cell survival associated with the complete finalization of DNA duplication