Enzymes
| UniProtKB help_outline | 719 proteins |
Reaction participants Show >> << Hide
- Name help_outline oxaloacetate Identifier CHEBI:16452 (CAS: 149-63-3) help_outline Charge -2 Formula C4H2O5 InChIKeyhelp_outline KHPXUQMNIQBQEV-UHFFFAOYSA-L SMILEShelp_outline [O-]C(=O)CC(=O)C([O-])=O 2D coordinates Mol file for the small molecule Search links Involved in 61 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline phosphate Identifier CHEBI:43474 Charge -2 Formula HO4P InChIKeyhelp_outline NBIIXXVUZAFLBC-UHFFFAOYSA-L SMILEShelp_outline OP([O-])([O-])=O 2D coordinates Mol file for the small molecule Search links Involved in 1,029 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline H+ Identifier CHEBI:15378 Charge 1 Formula H InChIKeyhelp_outline GPRLSGONYQIRFK-UHFFFAOYSA-N SMILEShelp_outline [H+] 2D coordinates Mol file for the small molecule Search links Involved in 9,932 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
Cross-references
| RHEA:73303 | RHEA:73304 | RHEA:73305 | RHEA:73306 | |
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| Reaction direction help_outline | undefined | left-to-right | right-to-left | bidirectional |
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Publications
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UCP2 transports C4 metabolites out of mitochondria, regulating glucose and glutamine oxidation.
Vozza A., Parisi G., De Leonardis F., Lasorsa F.M., Castegna A., Amorese D., Marmo R., Calcagnile V.M., Palmieri L., Ricquier D., Paradies E., Scarcia P., Palmieri F., Bouillaud F., Fiermonte G.
Uncoupling protein 2 (UCP2) is involved in various physiological and pathological processes such as insulin secretion, stem cell differentiation, cancer, and aging. However, its biochemical and physiological function is still under debate. Here we show that UCP2 is a metabolite transporter that re ... >> More
Uncoupling protein 2 (UCP2) is involved in various physiological and pathological processes such as insulin secretion, stem cell differentiation, cancer, and aging. However, its biochemical and physiological function is still under debate. Here we show that UCP2 is a metabolite transporter that regulates substrate oxidation in mitochondria. To shed light on its biochemical role, we first studied the effects of its silencing on the mitochondrial oxidation of glucose and glutamine. Compared with wild-type, UCP2-silenced human hepatocellular carcinoma (HepG2) cells, grown in the presence of glucose, showed a higher inner mitochondrial membrane potential and ATP:ADP ratio associated with a lower lactate release. Opposite results were obtained in the presence of glutamine instead of glucose. UCP2 reconstituted in lipid vesicles catalyzed the exchange of malate, oxaloacetate, and aspartate for phosphate plus a proton from opposite sides of the membrane. The higher levels of citric acid cycle intermediates found in the mitochondria of siUCP2-HepG2 cells compared with those found in wild-type cells in addition to the transport data indicate that, by exporting C4 compounds out of mitochondria, UCP2 limits the oxidation of acetyl-CoA-producing substrates such as glucose and enhances glutaminolysis, preventing the mitochondrial accumulation of C4 metabolites derived from glutamine. Our work reveals a unique regulatory mechanism in cell bioenergetics and provokes a substantial reconsideration of the physiological and pathological functions ascribed to UCP2 based on its purported uncoupling properties. << Less
Proc. Natl. Acad. Sci. U.S.A. 111:960-965(2014) [PubMed] [EuropePMC]
This publication is cited by 7 other entries.