BAD and glucokinase reside in a mitochondrial complex that integrates glycolysis and apoptosis

• Published in: Nature 2003-08, Vol.424 (6951), p.952-956
• Main Authors: Korsmeyer, Stanley J, Danial, Nika N, Gramm, Colette F, Scorrano, Luca, Zhang, Chen-Yu, Krauss, Stefan, Ranger, Ann M, Robert Datta, Sandeep, Greenberg, Michael E, Licklider, Lawrence J, Lowell, Bradford B, Gygi, Steven P
• Format: Article
• Language: English
• Subjects: Ageing, cell death; Animals; Apoptosis; bcl-Associated Death Protein; Biological and medical sciences; Carrier Proteins - genetics; Carrier Proteins - metabolism; Cell division; Cell physiology; Fundamental and applied biological sciences. Psychology; Gene Deletion; Genetics; Glucokinase - metabolism; Glucose; Glucose - metabolism; Glycolysis; Holoenzymes - metabolism; Homeostasis; Macromolecular Substances; Mice; Mice, Knockout; Mitochondria, Liver - chemistry; Mitochondria, Liver - enzymology; Mitochondria, Liver - metabolism; Molecular and cellular biology; Phosphorylation; Physiology; Proteomics; Proto-Oncogene Proteins c-bcl-2 - genetics; Proto-Oncogene Proteins c-bcl-2 - metabolism
• ISSN: 0028-0836; 1476-4687
• DOI: 10.1038/nature01825

Glycolysis and apoptosis are considered major but independent pathways that are critical for cell survival. The activity of BAD, a pro-apoptotic BCL-2 family member, is regulated by phosphorylation in response to growth/survival factors. Here we undertook a proteomic analysis to assess whether BAD might also participate in mitochondrial physiology. In liver mitochondria, BAD resides in a functional holoenzyme complex together with protein kinase A and protein phosphatase 1 (PP1) catalytic units, Wiskott-Aldrich family member WAVE-1 as an A kinase anchoring protein, and glucokinase (hexokinase IV). BAD is required to assemble the complex in that Bad-deficient hepatocytes lack this complex, resulting in diminished mitochondria-based glucokinase activity and blunted mitochondrial respiration in response to glucose. Glucose deprivation results in dephosphorylation of BAD, and BAD-dependent cell death. Moreover, the phosphorylation status of BAD helps regulate glucokinase activity. Mice deficient for BAD or bearing a non-phosphorylatable BAD(3SA) mutant display abnormal glucose homeostasis including profound defects in glucose tolerance. This combination of proteomics, genetics and physiology indicates an unanticipated role for BAD in integrating pathways of glucose metabolism and apoptosis.