JCB logo
PeproTech: Cell Culture Supplements
  Home | Help | Feedback | Subscriptions | Archive | Search | Table of Contents
Published online 8 October 2001. doi:10.1083/jcb.200105137
This Article
Right arrow Full Text
Right arrow Full Text (PDF, 299K)
Right arrow PPT slides of all figures
Right arrow Alert me when this article is cited
Right arrow Citation Map
Services
Right arrow Email this article
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new content in the JCB
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via CrossRef
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Fortin, A.
Right arrow Articles by Slack, R. S.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Fortin, A.
Right arrow Articles by Slack, R. S.
Right arrowPubmed/NCBI databases
*OMIM
*Compound via MeSH
*Substance via MeSH
Social Bookmarking
Add to CiteULike   Add to Complore   Add to Connotea   Add to Del.icio.us   Add to Digg   Add to Reddit   Add to Technorati  
What's this?

© The Rockefeller University Press, 0021-9525/2001/10/207 $5.00
The Journal of Cell Biology, Volume 155, Number 2, October 15, 2001 207-216

Article

APAF1 is a key transcriptional target for p53 in the regulation of neuronal cell death



Andre Fortin1, Sean P. Cregan1, Jason G. MacLaurin1, Neena Kushwaha1, Emma S. Hickman3, Charlie S. Thompson1, Antoine Hakim1, Paul R. Albert1,2, Francesco Cecconi4, Kristian Helin3, David S. Park1,2 and Ruth S. Slack1,2

1 Ottawa Health Research Institute - Neuroscience, University of Ottawa, Ottawa, Ontario K1H-8M5, Canada
2 Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Ontario K1H-8M5, Canada
3 Department of Experimental Oncology, European Institute of Oncology, 20141 Milan, Italy
4 Department of Biology, University of Rome "Tor Vergata", 00133 Rome, Italy

Address correspondence to Ruth S. Slack, Ottawa Health Research Institute - Neuroscience, University of Ottawa, 451 Smyth Rd., Ottawa, ON K1H-8M5, Canada. Tel.: (613) 562-5800. Fax: (613) 562-5403. E-mail: rslack{at}uottawa.ca

p53 is a transcriptional activator which has been implicated as a key regulator of neuronal cell death after acute injury. We have shown previously that p53-mediated neuronal cell death involves a Bax-dependent activation of caspase 3; however, the transcriptional targets involved in the regulation of this process have not been identified. In the present study, we demonstrate that p53 directly upregulates Apaf1 transcription as a critical step in the induction of neuronal cell death. Using DNA microarray analysis of total RNA isolated from neurons undergoing p53-induced apoptosis a 5–6-fold upregulation of Apaf1 mRNA was detected. Induction of neuronal cell death by camptothecin, a DNA-damaging agent that functions through a p53-dependent mechanism, resulted in increased Apaf1 mRNA in p53-positive, but not p53-deficient neurons. In both in vitro and in vivo neuronal cell death processes of p53-induced cell death, Apaf1 protein levels were increased. We addressed whether p53 directly regulates Apaf1 transcription via the two p53 consensus binding sites in the Apaf1 promoter. Electrophoretic mobility shift assays demonstrated p53–DNA binding activity at both p53 consensus binding sequences in extracts obtained from neurons undergoing p53-induced cell death, but not in healthy control cultures or when p53 or the p53 binding sites were inactivated by mutation. In transient transfections in a neuronal cell line with p53 and Apaf1 promoter–luciferase constructs, p53 directly activated the Apaf1 promoter via both p53 sites. The importance of Apaf1 as a p53 target gene in neuronal cell death was evaluated by examining p53-induced apoptotic pathways in primary cultures of Apaf1-deficient neurons. Neurons treated with camptothecin were significantly protected in the absence of Apaf1 relative to those derived from wild-type littermates. Together, these results demonstrate that Apaf1 is a key transcriptional target for p53 that plays a pivotal role in the regulation of apoptosis after neuronal injury.

Key Words: apoptosis; neurodegeneration; neurons; bax; caspase 3


Add to CiteULike CiteULike   Add to Complore Complore   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us   Add to Digg Digg   Add to Reddit Reddit   Add to Technorati Technorati    What's this?


This article has been cited by other articles:



  Home | Help | Feedback | Subscriptions | Archive | Search | Table of Contents