Hypoxia‐activated metabolic pathway stimulates phosphorylation of p300 and CBP in oxygen‐sensitive cells

• Published in: Journal of neurochemistry Vol. 94; no. 5; pp. 1288 - 1296
• Main Authors: Zakrzewska, Adriana, Schnell, Phillip O., Striet, Justin B., Hui, Anna, Robbins, Jennifer R., Petrovic, Milan, Conforti, Laura, Gozal, David, Wathelet, Marc G., Czyzyk‐Krzeska, Maria F.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Science Ltd 01-09-2005; Blackwell; Blackwell Publishing Ltd
• Subjects: Adenosine; Adrenals. Adrenal axis. Renin-angiotensin system (diseases); Animals; Biochemistry; Biological and medical sciences; Calcium; Calcium - metabolism; Carotid Body - drug effects; Carotid Body - metabolism; Carotid Body - pathology; carotid body respiratory chain; Cell Line; E1A-Associated p300 Protein; Endocrinopathies; Gastroenterology. Liver. Pancreas. Abdomen; Glucose - metabolism; Humans; Hypoxia - metabolism; Hypoxia - pathology; Hypoxia - physiopathology; hypoxia‐inducible factor; Inhibitor drugs; Inositol 1,4,5-Trisphosphate - metabolism; intermittent hypoxia; Liver. Biliary tract. Portal circulation. Exocrine pancreas; Male; Medical sciences; Non tumoral diseases. Target tissue resistance. Benign neoplasms; Nuclear Proteins - metabolism; Other diseases. Semiology; Oxygen - pharmacology; PC12 Cells - drug effects; PC12 Cells - metabolism; Phosphorylation; Rats; Rats, Sprague-Dawley; Trans-Activators - metabolism; transcription co‐activators; Endocrinopathy; Phosphorylation; Pheochromocytoma; Rat; Transcription; Hepatic disease; Activation; Metabolic pathway; carotid body respiratory chain; Secretory tumor; Binding protein; Gene; Hepatoblastoma; Inositol 1,4,5-trisphosphate; Acyltransferases; Oxygen; calcium; Enzyme; Transferases; Rodentia; Cyclic AMP; Ions; P300 potential; Malignant tumor; transcription co-activators; Histone acetyltransferase; intermittent hypoxia; Chemoreceptor; Vertebrata; Mammalia; Digestive diseases; Hypoxia; hypoxia- inducible factor
• ISSN: 0022-3042; 1471-4159
• DOI: 10.1111/j.1471-4159.2005.03293.x

Transcription co‐activators and histone acetyltransferases, p300 and cyclic AMP responsive element‐binding protein‐binding protein (CBP), participate in hypoxic activation of hypoxia‐inducible genes. Here, we show that exposure of PC12 and cells to 1–10% oxygen results in hyperphosphorylation of p300/CBP. This response is fast, long lasting and specific for hypoxia, but not for hypoxia‐mimicking agents such as desferioxamine or Co2+ ions. It is also cell‐type specific and occurs in pheochromocytoma PC12 cells and the carotid body of rats but not in hepatoblastoma cells. The p300 hyperphosphorylation specifically depends on the release of intracellular calcium from inositol 1,4,5‐triphosphate (IP3)‐sensitive stores. However, it is not inhibited by pharmacological inhibitors of any of the kinases traditionally known to be directly or indirectly calcium regulated. On the other hand, p300 hyperphosphorylation is inhibited by several different inhibitors of the glucose metabolic pathway from generation of NADH by glyceraldehyde 3‐phosphate dehydrogenase, through the transfer of NADH through the glycerol phosphate shuttle to ubiquinone and complex III of the mitochondrial respiratory chain. Inhibition of IP3‐sensitive calcium stores decreases generation of ATP, and this inhibition is significantly stronger in hypoxia than in normoxia. We propose that the NADH glycerol phosphate shuttle participates in generating a pool of ATP that serves either as a co‐factor or a modulator of the kinases involved in the phosphorylation of p300/CBP during hypoxia.