IDH1 Antibody (Center) Blocking Peptide

Isocitrate dehydrogenases catalyze the oxidative decarboxylation of isocitrate to 2-oxoglutarate. These enzymes belong to two distinct subclasses, one of which utilizes NAD(+) as the electron acceptor and the other NADP(+). Five isocitrate dehydrogenases have been reported: three NAD(+)-dependent isocitrate dehydrogenases, which localize to the mitochondrial matrix, and two NADP(+)-dependent isocitrate dehydrogenases, one of which is mitochondrial and the other predominantly cytosolic. Each NADP(+)-dependent isozyme is a homodimer. The protein encoded by this gene is the NADP(+)-dependent isocitrate dehydrogenase found in the cytoplasm and peroxisomes. It contains the PTS-1 peroxisomal targeting signal sequence. The presence of this enzyme in peroxisomes suggests roles in the regeneration of NADPH for intraperoxisomal reductions, such as the conversion of 2, 4-dienoyl-CoAs to 3-enoyl-CoAs, as well as in peroxisomal reactions that consume 2-oxoglutarate, namely the alpha-hydroxylation of phytanic acid. The cytoplasmic enzyme serves a significant role in cytoplasmic NADPH production. Alternatively spliced transcript variants encoding the same protein have been found for this gene. [provided by RefSeq, Sep 2013]

IDH1: an oxidoreductase that catalyzes the third step of the TCA cycle: the oxidative decarboxylation of isocitrate, consuming NADP(+), and producing alpha-ketoglutarate (alpha-KG) and CO2. Alpha-KG is an activator the dioxygenases that hydroxylate the transcription factor HIF and lead to its degradation by VHL. Since HIF turns on oncogenic pathways, IDH1 has apparent tumor suppressor activity. Homo-dimerization is required for activity. Each subunit binds 1 magnesium or manganese ion. IDH1 is located in the cytosol and peroxisomes. Somatic mutations affecting arginine 132 (R132) are found in 80% of grade II?III gliomas and secondary glioblastomas in humans, and cause disease in a tissue-specific fashion. Only a single copy of the gene has been found to be mutated in tumours. Mutations of R132 to H, C, S, G, V, or L have been reported to be neomorphic, abolishing the conversion of isocitrate to alpha-KG. Instead, alpha-KG is converted to R(-)-2-hydroxyglutarate (2HG). Elevated levels of 2HG correlate with an elevated risk of malignant brain tumors. Neomorphic mutations in IDH1 and IDH2 convert alpha-KG to 2-hydroxyglutarate (2-HG) occur in a high percentage of patients with cytogenetically normal acute myeloid leukemia (AML).

Protein type: EC 1.1.1.42; Oxidoreductase; Carbohydrate Metabolism - citrate (TCA) cycle; Other Amino Acids Metabolism - glutathione

Chromosomal Location of Human Ortholog: 2q33.3

Cellular Component: cytoplasm; cytosol; peroxisomal matrix; peroxisome

Molecular Function: (R)-2-hydroxyglutarate dehydrogenase activity; isocitrate dehydrogenase (NADP+) activity; magnesium ion binding; protein homodimerization activity; receptor binding

Biological Process: 2-oxoglutarate metabolic process; isocitrate metabolic process; NADPH regeneration

Disease: Glioma Susceptibility 1