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]

Tumor type associations:

  • Bladder
  • Colorectal
  • Endometrial
  • Liver
  • Melanoma
  • Enablesmagnesium ion binding
  • Esocitrate dehydrogenase activity
  • Enables isocitrate dehydrogenase (NADP+) activity
  • Enables protein binding
  • Oxidoreductase activity
  • Located in extracellular region
  • Located in cytoplasm
  • Is active in mitochondrion
  • Located in peroxisome
  • Located in peroxisomal matrix
  • Involved in glyoxylate cycle
  • Involved in tricarboxylic acid cycle
  • Involved in isocitrate metabolic process
  • Involved in 2-oxoglutarate metabolic process
  • Involved in NADP metabolic process
  • Glioma, susceptibility to, somatic

IDH1 localizations – Subcellular Localization Database

Gene Location