Inhibition of apoptosis by ATFx: a novel role for a member of the ATF/CREB family of mammalian bZIP transcription factors
Abstract
The mammalian ATF/CREB family of transcription factors comprises a large group of basic-region leucine zipper (bZIP) proteins whose members mediate diverse transcriptional regulatory functions. Here we report that expression of a specific mouse ATF gene,ATFx, is down-regulated in a variety of cells undergoing apoptosis following growth factor deprivation. When stably expressed in an interleukin 3 (IL-3)-dependent cell line, ATFx suppresses apoptosis resulting from cytokine deprivation. Conversely, a dominant-negative ATFx mutant induces apoptosis of cells cultured in the presence of growth factors. We also show that 24p3, a secreted lipocalin that induces apoptosis when added to hematopoietic cells, represses ATFx expression. However, constitutive expression ofATFx renders cells resistant to 24p3-mediated apoptosis. Collectively, our results indicate that ATFx is an anti-apoptotic factor, a novel role for an ATF protein.
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↵1 Corresponding author.
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E-MAIL michael.green{at}umassmed.edu; FAX (508) 856-5473.
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Article and publication are at http://www.genesdev.org/cgi/doi/10.1101/gad.992202.
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- Received March 18, 2002.
- Accepted May 22, 2002.
- Cold Spring Harbor Laboratory Press