Abstract
P53-upregulated modifier of apoptosis (PUMA), a pro-apoptotic member of the Bcl-2 family, is transcriptionally activated by p53 and is a key effector of p53-dependent apoptosis. We show that PUMA protein is subject to rapid post-translational regulation by phosphorylation at a conserved residue, serine 10, following serum or interleukin-3 (IL-3) stimulation. Serine 10 is not within the Bcl-2 homology (BH3) domain, and PUMA phosphorylated at serine 10 retained the ability to co-immunoprecipitate with antiapoptotic Bcl-2 family members. However, phosphorylated PUMA was targeted for proteasomal degradation indicating that it is less stable than unphosphorylated PUMA. Importantly, we identified IKK1/IKK2/Nemo as the kinase complex that interacts with and phosphorylates PUMA, thereby also demonstrating that IL-3 activates NFκB signaling. The identification and characterization of this novel survival pathway has important implications for IL-3 signaling and hematopoietic cell development.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Animals
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Apoptosis Regulatory Proteins / genetics
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Apoptosis Regulatory Proteins / metabolism*
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Cell Death / physiology
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Cell Line
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Hematopoietic Stem Cells / cytology
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Hematopoietic Stem Cells / metabolism*
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Humans
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I-kappa B Kinase / genetics
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I-kappa B Kinase / metabolism*
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Interleukin-3 / genetics
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Interleukin-3 / metabolism
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Mice
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Mice, Knockout
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NF-kappa B / genetics
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NF-kappa B / metabolism
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Phosphorylation / physiology
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Proteasome Endopeptidase Complex / genetics
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Proteasome Endopeptidase Complex / metabolism
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Protein Processing, Post-Translational / physiology*
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Proteolysis
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Proto-Oncogene Proteins / genetics
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Proto-Oncogene Proteins / metabolism*
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Receptors, Interleukin-3 / genetics
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Receptors, Interleukin-3 / metabolism*
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Signal Transduction / physiology*
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Tumor Suppressor Protein p53 / genetics
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Tumor Suppressor Protein p53 / metabolism
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Tumor Suppressor Proteins / genetics
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Tumor Suppressor Proteins / metabolism*
Substances
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Apoptosis Regulatory Proteins
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BBC3 protein, human
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IL3 protein, human
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Interleukin-3
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NF-kappa B
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PUMA protein, mouse
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Proto-Oncogene Proteins
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Receptors, Interleukin-3
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TP53 protein, human
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Tumor Suppressor Protein p53
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Tumor Suppressor Proteins
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I-kappa B Kinase
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Proteasome Endopeptidase Complex