Akt requires glucose metabolism to suppress puma expression and prevent apoptosis of leukemic T cells.

Abstract

The PI3K/Akt pathway is activated in stimulated cells and in many cancers to promote glucose metabolism and prevent cell death. Although inhibition of Akt-mediated cell survival may provide a means to eliminate cancer cells, this survival pathway remains incompletely understood. In particular, unlike anti-apoptotic Bcl-2 family proteins that prevent apoptosis independent of glucose, Akt requires glucose metabolism to inhibit cell death. This glucose dependence may occur in part through metabolic regulation of pro-apoptotic Bcl-2 family proteins. Here, we show that activated Akt relies on glycolysis to inhibit induction of Puma, which was uniquely sensitive to metabolic status among pro-apoptotic Bcl-2 family members and was rapidly up-regulated in glucose-deficient conditions. Importantly, preventing Puma expression was critical for Akt-mediated cell survival, as Puma deficiency protected cells from glucose deprivation and Akt could not readily block Puma-mediated apoptosis. In contrast, the pro-apoptotic Bcl-2 family protein Bim was induced normally even when constitutively active Akt was expressed, yet Akt could provide protection from Bim cytotoxicity. Up-regulation of Puma appeared mediated by decreased availability of mitochondrial metabolites rather than glycolysis itself, as alternative mitochondrial fuels could suppress Puma induction and apoptosis upon glucose deprivation. Metabolic regulation of Puma was mediated through combined p53-dependent transcriptional induction and control of Puma protein stability, with Puma degraded in nutrient-replete conditions and long lived in nutrient deficiency. Together, these data identify a key role for Bcl-2 family proteins in Akt-mediated cell survival that may be critical in normal immunity and in cancer through Akt-dependent stimulation of glycolysis to suppress Puma expression.

• Authors: Jonathan L Coloff, Emily F Mason, Brian J Altman, Valerie A Gerriets, Tingyu Liu, Amanda N Nichols, Yuxing Zhao, Jessica A Wofford, Sarah R Jacobs, Olga Ilkayeva, Sean P Garrison, Gerard P Zambetti, Jeffrey C Rathmell
• Journal: The Journal of biological chemistry (J Biol Chem) Vol. 286 Issue 7 Pg. 5921-33 (Feb 18 2011) ISSN: 1083-351X [Electronic] United States
• PMID: 21159778 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)

Chemical References

• Apoptosis Regulatory Proteins
• BBC3 protein, human
• BCL2L11 protein, human
• Bcl-2-Like Protein 11
• Bcl2l11 protein, mouse
• Membrane Proteins
• PUMA protein, mouse
• Proto-Oncogene Proteins
• Proto-Oncogene Proteins c-bcl-2
• TP53 protein, human
• Tumor Suppressor Protein p53
• Tumor Suppressor Proteins
• Proto-Oncogene Proteins c-akt
• Glucose

Topics

• Animals
• Apoptosis
• Apoptosis Regulatory Proteins (biosynthesis, genetics, metabolism)
• Bcl-2-Like Protein 11
• Cell Survival (genetics)
• Gene Expression Regulation, Leukemic
• Glucose (genetics, metabolism)
• Glycolysis (genetics)
• Humans
• Jurkat Cells
• Membrane Proteins (genetics, metabolism)
• Mice
• Mitochondria (genetics, metabolism)
• Precursor T-Cell Lymphoblastic Leukemia-Lymphoma (genetics, metabolism)
• Proto-Oncogene Proteins (biosynthesis, genetics, metabolism)
• Proto-Oncogene Proteins c-akt (genetics, metabolism)
• Proto-Oncogene Proteins c-bcl-2 (genetics, metabolism)
• Tumor Suppressor Protein p53 (genetics, metabolism)
• Tumor Suppressor Proteins (biosynthesis, genetics)
• Up-Regulation (genetics)