These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Systematic genetic dissection of p14ARF-mediated mitochondrial cell death signaling reveals a key role for p21CDKN1 and the BH3-only protein Puma/bbc3.
    Author: Hemmati PG, Müer A, Gillissen B, Overkamp T, Milojkovic A, Wendt J, Dörken B, Daniel PT.
    Journal: J Mol Med (Berl); 2010 Jun; 88(6):609-22. PubMed ID: 20419447.
    Abstract:
    Induction of cell death by p14(ARF) is mediated through a Bax/Bak-dependent mitochondrial apoptosis pathway. To investigate the upstream signaling events required for the activation of Bax and/or Bak and to determine the functional impact of de-regulated cell cycle restriction point control in this context, we genetically dissected the impact of BH3-only proteins and the role of the cyclin-dependent kinase (cdk) inhibitor p21(CDKN1). Using isogenic HCT116 colorectal cancer cells, either wild-type or homozygously deleted for the BH3-only protein Puma/bbc3 and/or p21(CDKN1) or p53-reconstituted DU145 prostate cancer cells, we show that p14(ARF)-induced apoptosis is attenuated in the absence of Puma. Upon expression of p14(ARF) in HCT116 cells, Puma is rapidly induced at both the mRNA and protein level. Puma-proficient HCT116 cells undergo apoptotic (nuclear) DNA fragmentation, which is preceded by the N-terminal conformational change of Bax, the breakdown of the mitochondrial membrane potential, and induction of caspase-9 (LEHD)-like and caspase-3/7 (DEVD)-like activities. In contrast, p14(ARF)-induced apoptosis is markedly attenuated in isogenic HCT116 cells bi-allelically deleted for puma. The sensitivity of Puma-deficient cells to p14(ARF)-induced apoptosis is fully restored by functional reconstitution of Puma using a conditional adenoviral expression vector. Notably, the concomitant deletion of p21(CDKN1) strongly enhances p14(ARF)-induced apoptosis in Puma-proficient cells, but not in isogenic Puma-deficient cells. These results indicate that p14(ARF)-induced mitochondrial apoptosis critically depends on the BH3-only protein Puma. In the presence of a functional p53/Puma/Bax-signaling axis, p14(ARF)-triggered apoptosis is enhanced by loss of p21(CDKN1)-mediated cell cycle checkpoint control.
    [Abstract] [Full Text] [Related] [New Search]