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Cancer Cell death Cell cycle Cytoskeleton Exo/endocytosis Differentiation Division Organelles Signalling Stem cells Trafficking
Cell Biology International (2009) 33, 318–324 (Printed in Great Britain)
RBP-Jκ binds to and represses transcription of the p53 tumor suppressor gene
Kristy Boggs1, Brystol Henderson and David Reisman*
Department of Biological Sciences, University of South Carolina, Columbia, SC 29208, USA


Abstract

The tightly regulated expression of p53 contributes to genomic stability and transcription of the p53 gene is induced prior to cells entering S-phase, possibly as a mechanism to insure a rapid p53 response in the event of DNA damage. We have previously described the cloning of an additional 1000bp of upstream p53 sequences that play a role in the regulated expression of p53, and identified that C/EBPβ-2 participates in inducing p53 gene expression in a cell cycle regulated fashion. This report deals with the transcriptional regulator, RBP-Jκ, an essential target of the Notch receptor signaling pathway. It binds to the p53 promoter in a cell cycle regulation fashion and also serves to repress p53 gene expression. We conclude from these findings that the coordinate expression of C/EBPβ-2 and RBP-Jκ may be linked to p53 transcription during G0 and as cells move into S-phase. Because defects in the Notch signaling pathway have been implicated in carcinogenesis, aberrant RBP-Jκ expression and deregulated regulation of the p53 tumor suppressor could be an important step in some forms of cancers.


Key words: Gene expression, Cell cycle, DNA binding.

1Present address: Department of Hematology–Oncology, St. Jude Children's Research Hospital, Memphis, TN, USA.

*Corresponding author. Tel.: +1 803 777 8108; fax: +1 803 777 4002.


Received 25 July 2008/26 September 2008; accepted 5 December 2008

doi:10.1016/j.cellbi.2008.12.005


ISSN Print: 1065-6995
ISSN Electronic: 1095-8355
Published by Portland Press Limited on behalf of the International Federation for Cell Biology (IFCB)