Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0028754 (obesity)
 124,988 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Increased proline levels were found in plasma of a girl with slight psychomotor retardation, epilepsy, obesity, scoliosis, hypocalcaemia, variable lymphocytopenia and facial dysmorphy suggestive of CATCH 22 syndrome. Fluorescence in situ hybridization indicated the presence of a submicroscopic 22q11 deletion, confirming this diagnosis. Further investigation showed evidence that the patient was heterozygous for heparin cofactor II deficiency and for hyperprolinaemia type I, a proline catabolic disorder due to proline oxidase deficiency. This association extends the CATCH 22 syndrome and suggests that expression of the proline oxidase gene depends on the chromosome 22q11 region.
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PMID:Association of hyperprolinaemia type I and heparin cofactor II deficiency with CATCH 22 syndrome: evidence for a contiguous gene syndrome locating the proline oxidase gene. 880 68

Proline, the only proteinogenic secondary amino acid, is metabolized by its own family of enzymes responding to metabolic stress and participating in metabolic signaling. Collagen in extracellular matrix, connective tissue, and bone is an abundant reservoir for proline. Matrix metalloproteinases degrading collagen are activated during stress to make proline available, and proline oxidase, the first enzyme in proline degradation, is induced by p53, peroxisome proliferator-activated receptor gamma (PPARgamma) and its ligands, and by AMP-activated protein kinase downregulating mTOR. Metabolism of proline generates electrons to produce ROS and initiates a variety of downstream effects, including blockade of the cell cycle, autophagy, and apoptosis. The electrons can also enter the electron transport chain to produce adenosine triphosphate for survival under nutrient stress. Pyrroline-5-carboxylate, the product of proline oxidation, is recycled back to proline with redox transfers or is sequentially converted to glutamate and alpha-ketoglutarate. The latter augments the prolyl hydroxylation of hypoxia-inducible factor-1alpha and its proteasomal degradation. These effects of proline oxidase, as well as its decreased levels in tumors, support its role as a tumor suppressor. The mechanism for its decrease is mediated by a specific microRNA. The metabolic signaling by proline oxidase between oxidized low-density lipoproteins and autophagy provides a functional link between obesity and increased cancer risk.
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PMID:Proline metabolism and microenvironmental stress. 2041 79