Oligomerisation of CHEK2 therefore increases the efficiency of transautophosphorylation resulting in the release of active CHEK2 monomers that proceed to enforce checkpoint control.
This loss of robust checkpoint control and subsequent escape from G2 arrest is likely due at least in part to destabilization of mutant p53, combined with a cellular state in which there is insufficient p21 activity (both intrinsically and via the HSP90 inhibitor-mediated loss of mutant p53) to enforce the checkpoints.
But, with rebel armies now roaming the eastern landscape, the government had declared a state of emergency in Abéché and imposed a six-thirty curfew, strictly enforced by checkpoints and pickups full of soldiers with AK-47s and RPGs.
Enforced checkpoint induction contributes to stem cell ageing.
In the city of Kashgar, checkpoints enforce what the authorities call "Project Beauty" — beauty, in this case, being an exposed face.
As a result of p53-mediated cis-activation of the TPPP1 gene, TPPP1 expression is increased to enforce cell cycle checkpoints.
If this were the case, then pharmacologically induced DNA-damage might elicit an increase in TPPP1 expression or activity to enforce cell cycle checkpoints enabling the repair of DNA or to induce apoptotic cell death programs.
Gan, B. et al. FoxOs enforce a progression checkpoint to constrain mTORC1-activated renal tumorigenesis.
Dimitrova, N. et al. LincRNA-p21 activates p21 in cis to promote Polycomb target gene expression and to enforce the G1/S checkpoint.
Genes that play important roles in the G1/S transition and initiation of DNA replication, including CCNE, CDK2, CDC6, CDC45, CDC7, RFC subunits, and MCM family members, were down-regulated at 6 and 24 hr post-IR as an expected consequence of the p53-dependent induction of CDKN1A (p21Waf1) to enforce the G1 checkpoint response.
