Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:4.1.1.17 (ornithine decarboxylase)
 6,351 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Natural polyamines (putrescine, spermidine and spermine) are ubiquitous molecules known to regulate a number of physiological processes and suspected to play a role also in various pathological conditions. Changes in polyamine levels and in their biosynthetic enzymes have been described for some neurodegenerative diseases but the available data are incomplete and somewhat contradictory. We report here alterations of the key enzyme of the polyamine pathway, ornithine decarboxylase (ODC) catalytic activity and polyamine levels in different CNS areas from SOD1 G39A transgenic mice, an animal model for amyotrophic lateral sclerosis (ALS). ODC catalytic activity, was found significantly increased both in the cervical and lumbar spinal cord and, to a lesser extent in the brain stem of transgenic mice at a symptomatic stage of the disease (125-day-old mice), while no differences were present at a pre-symptomatic stage (55-day-old mice). In parallel with the increase of ODC activity putrescine levels were several times increased in both cervical and lumbar spinal cord and in the brain stem of 125-day-old SOD1 G39A mice. Higher order polyamines were not increased except for a significant increase of spermidine in the cervical spinal cord. The present data demonstrate considerable alterations of the ODC/polyamine system in a reliable animal model of ASL, consistent with their role in neurodegeneration and in particular in motor neuron diseases.
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PMID:Regional and temporal alterations of ODC/polyamine system during ALS-like neurodegenerative motor syndrome in G93A transgenic mice. 1629 Feb 66

Citrulline, a non-protein amino acid, is present in large amounts in watermelon (Citrullus lanatus (Thunb.) Matsum. & Nakai Cucurbitaceae) fruits. Amino acid profiling of various tissues of cv. Charleston Gray during plant development confirmed progressive accumulation of citrulline only in the fruit flesh and rind tissues. Citrulline content was positively correlated with precursor (ornithine) and by-product (arginine) amino acids during fruit ripening. Genetic variation in the partitioning of citrulline and related amino acids in the flesh and rind tissues was confirmed in a sub-set of watermelon cultivars. No correlation was established between morphological fruit traits (size and rind properties) and citrulline content. To understand the regulation of citrulline accumulation, we investigated the expression of genes associated with its biosynthesis and catabolism in flesh and rind tissues during fruit development. The expression of ornithine carbamoyltransferase (OTC) involved in the ultimate step of citrulline synthesis remained steady in both tissues. The expression of N-acetylornithine aminotransferase (N-AOA) involved in the production of N-acetylornithine and N-acetylornithine deacetylase (AOD-3) involved in ornithine synthesis coincided with increasing accumulation of citrulline in flesh and rind tissues during fruit development. Down-regulation N-acetylornithine-glutamate acetyltransferase (N-AOGA) suggests the subordinate role of the non-cyclic pathway in citrulline synthesis. Eccentricity between citrulline accumulation and expression of carbamoyl phosphate synthases (CPS-1, CPS-2) during fruit development suggest that the localized synthesis of carbamoyl phosphates may not be required for citrulline synthesis. Most genes involved in citrulline break-down (Argininosuccinate synthases - ASS-1, ASS-2, and ASS-3, Argininosuccinate lyases - ASL-1, Ornithine decarboxylase - ODC, Arginine decarboxylase - ADC) were consistently down-regulated during fruit development.
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PMID:Systematized biosynthesis and catabolism regulate citrulline accumulation in watermelon. 3088 57