MCB
Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowReprints and Permissions
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Vigo, E.
Right arrow Articles by Helin, K.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Vigo, E.
Right arrow Articles by Helin, K.

 Previous Article  |  Next Article 

Molecular and Cellular Biology, September 1999, p. 6379-6395, Vol. 19, No. 9
0270-7306/99/$04.00+0
Copyright © 1999, American Society for Microbiology. All rights reserved.

CDC25A Phosphatase Is a Target of E2F and Is Required for Efficient E2F-Induced S Phase

Elena Vigo, Heiko Müller, Elena Prosperini, Guus Hateboer, Peter Cartwright, Maria Cristina Moroni, and Kristian Helin*

Department of Experimental Oncology, European Institute of Oncology, 20141 Milan, Italy

Received 20 January 1999/Returned for modification 28 May 1999/Accepted 14 June 1999

Functional inactivation of the pRB pathway is a very frequent event in human cancer, resulting in deregulated activity of the E2F transcription factors. To understand the functional role of the E2Fs in cell proliferation, we have developed cell lines expressing E2F-1, E2F-2, and E2F-3 fused to the estrogen receptor ligand binding domain (ER). In this study, we demonstrated that activation of all three E2Fs could relieve the mitogen requirement for entry into S phase in Rat1 fibroblasts and that E2F activity leads to a shortening of the G0-G1 phase of the cell cycle by 6 to 7 h. In contrast to the current assumption that E2F-1 is the only E2F capable of inducing apoptosis, we showed that deregulated E2F-2 and E2F-3 activities also result in apoptosis. Using the ERE2F-expressing cell lines, we demonstrated that several genes containing E2F DNA binding sites are efficiently induced by the E2Fs in the absence of protein synthesis. Furthermore, CDC25A is defined as a novel E2F target whose expression can be directly regulated by E2F-1. Data showing that CDC25A is an essential target for E2F-1, since its activity is required for efficient induction of S phase by E2F-1, are provided. Finally, our results show that expression of two E2F target genes, namely CDC25A and cyclin E, is sufficient to induce entry into S phase in quiescent fibroblasts. Taken together, our results provide an important step in defining how E2F activity leads to deregulated proliferation.

* Corresponding author. Mailing address: Department of Experimental Oncology, European Institute of Oncology, Via Ripamonti 435, 20141 Milan, Italy. Phone: 39 02 5748 9860. Fax: 39 02 5748 9851. E-mail: khelin{at}ieo.cilea.it.

Molecular and Cellular Biology, September 1999, p. 6379-6395, Vol. 19, No. 9
0270-7306/99/$04.00+0
Copyright © 1999, American Society for Microbiology. All rights reserved.


This article has been cited by other articles:



Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
J. Bacteriol. J. Virol. Eukaryot. Cell
Microbiol. Mol. Biol. Rev. Clin. Vaccine Immunol. All ASM Journals

Copyright © 1999 by the American Society for Microbiology. All rights reserved.