The regulation of AMPK beta1, TSC2, and PTEN expression by p53: stress, cell and tissue specificity, and the role of these gene products in modulating the IGF-1-AKT-mTOR pathways.
The insulin-like growth factor 1 (IGF-1)-AKT-mTOR pathways sense the availability of nutrients and mitogens and respond by signaling for cell growth and division. The p53 pathway senses a variety of stress signals which will reduce the fidelity of cell growth and division, and responds by initiating cell cycle arrest, senescence, or apoptosis. This study explores four p53-regulated gene products, the beta1 and beta2 subunits of the AMPK, which are shown for the first time to be regulated by the p53 protein, TSC2, PTEN, and IGF-BP3, each of which negatively regulates the IGF-1-AKT-mTOR pathways after stress. These gene products are shown to be expressed under p53 control in a cell type and tissue-specific fashion with the TSC2 and PTEN proteins being coordinately regulated in those tissues that use insulin-dependent energy metabolism (skeletal muscle, heart, white fat, liver, and kidney). In addition, these genes are regulated by p53 in a stress signal-specific fashion. The mTOR pathway also communicates with the p53 pathway. After glucose starvation of mouse embryo fibroblasts, AMPK phosphorylates the p53 protein but does not activate any of the p53 responses. Upon glucose starvation of E1A-transformed mouse embryo fibroblasts, a p53-mediated apoptosis ensues. Thus, there is a great deal of communication between the p53 pathway and the IGF-1-AKT and mTOR pathways.
Feng
Zhaohui
Z
Cancer Institute of New Jersey, University of Medicine and Dentistry of New Jersey, New Brunswick, New Jersey, USA.
Hu
Wenwei
W
de Stanchina
Elisa
E
Teresky
Angelika K
AK
Jin
Shengkan
S
Lowe
Scott
S
Levine
Arnold J
AJ
D055372:AMP-Activated Protein Kinases; D017501:Adenovirus E1B Proteins / Q000378:metabolism; D000818:Animals; D017209:Apoptosis / Q000502:physiology; D045744:Cell Line, Tumor; D002471:Cell Transformation, Neoplastic; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D005947:Glucose / Q000172:deficiency; D006801:Humans; D018969:Insulin-Like Growth Factor Binding Proteins / Q000096:biosynthesis / Q000235:genetics; D007334:Insulin-Like Growth Factor I / Q000378:metabolism*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009097:Multienzyme Complexes; D009928:Organ Specificity; D051059:PTEN Phosphohydrolase / Q000096:biosynthesis* / Q000235:genetics; D011494:Protein Kinases / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism*; D017346:Protein Serine-Threonine Kinases; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism*; D015398:Signal Transduction; D058570:TOR Serine-Threonine Kinases; D000077005:Tuberous Sclerosis Complex 2 Protein; D016159:Tumor Suppressor Protein p53 / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D025521:Tumor Suppressor Proteins / Q000096:biosynthesis* / Q000235:genetics; D018631:ras Proteins / Q000378:metabolism
D017501:Adenovirus E1B Proteins; D018969:Insulin-Like Growth Factor Binding Proteins; D009097:Multienzyme Complexes; C000624653:TSC2 protein, human; C000624654:Tsc2 protein, mouse; D000077005:Tuberous Sclerosis Complex 2 Protein; D016159:Tumor Suppressor Protein p53; D025521:Tumor Suppressor Proteins; D007334:Insulin-Like Growth Factor I; D011494:Protein Kinases; C546842:MTOR protein, human; C546843:mTOR protein, mouse; C526182:PRKAB1 protein, human; C526183:PRKAB2 protein, human; D017346:Protein Serine-Threonine Kinases; D051057:Proto-Oncogene Proteins c-akt; D058570:TOR Serine-Threonine Kinases; D055372:AMP-Activated Protein Kinases; D051059:PTEN Phosphohydrolase; D018631:ras Proteins; D005947:Glucose