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)

Chronic administration of 1,3-diaminopropane, a compound inhibiting mammalian ornithine decarboxylase (EC 4.1.1.17) in vivo, effectively prevented the large increases in the concentration of putrescine that normally occur during rat liver regeneration. Furthermore, repeated injections of diaminopropane depressed by more than 85% ornithine decarboxylase activity in rat kidney. Administration of diaminopropane 60 min before partial hepatectomy only marginally inhibited ornithine decarboxylase activity at 4 h after the operation. However, when the compound was given at the time of the operation (4 h before death), or any time thereafter, it virtually abolished the enhancement in ornithine decarboxylase activity in regenerating rat liver remnant. An injection of diaminopropane given 30 to 60 min after operation, but not earlier or later, depressed S-adenosyl-L-methionine decarboxylase activity (EC 4.1.1.50) 4 h after partial hepatectomy. Diaminopropane likewise inhibited ornithine decarboxylase activity during later periods of liver regeneration. In contrast to early regeneration, a total inhibition of the enzyme activity was only achieved when the injection was given not earlier than 2 to 3 h before the death of the animals. Diaminopropane also exerted an acute inhibitory effect on adenosylmethionine decarboxylase activity in 28-h regenerating liver whereas it invariably enhanced the activity of tyrosine aminotransferase (EC 2.6.1.5), used as a standard enzyme of short half-life. Treatment of the rats with diaminopropane entirely abolished the stimulation of spermidien synthesis in vivo from [14C]methionine 4 h after partial hepatectomy or after administration of porcine growth hormone. Both partial hepatectomy and the treatment with growth hormone produced a clear stimulation of hepatic RNA synthesis, the extent of which was not altered by injections of diaminopropane in doses sufficient to prevent any enhancement of ornithine decarboxylase activity and spermidine synthesis.
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PMID:Specific inhibition of the synthesis of putrescine and spermidine by 1,3-diaminopropane in rat liver in vivo. 1 7

Chinese hamster V79 cells were synchronized by mitotic selection, which resulted in approximately 95% synchrony. The adenosine 3':5'-cyclic monophosphate level was elevated within 3 hr (G1 phase) and reached a level 2-fold higher than in early G1 within 6 hr (early S phase). An increase in ornithine decarboxylase activity (6-ornithine carboxy-lyase, EC 4.1.1.17), the initial enzyme in the polyamine biosynthetic pathway, was detected within 4 hr and was maximal at 8 hr. Since about 20% of the cells were labeled with [3-H]thymidine at 4 hr, ornithine decarboxylase exhibits cell-cycle specific activity starting in late G1 and continuing through middle S phase. The activity of S-adenosylmethionine decarboxylase (S-adenosyl-L-methionine carboxylase, EC 4.1.1.50) increased within 5 hr, i.e., early S phase. It is suggested on the basis of these data and other studies discussed herein that the increase in ornithine decarboxylase activity, which parallels closely the elevation in cyclic AMP, is an example of adenosine 3':5'-cyclic monophosphate-mediated protein synthesis.
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PMID:Cell cycle specific fluctuations in adenosine 3':5'-cyclic monophosphate and polyamines of Chinese hamster cells. 16 12

The distribution of polyamines between the nucleus and the cytoplasm, and the role of the nucleus in polyamine metabolism, have been studied using cells enucleated with cytochalasin B. Spermidine and spermine were found in the nuclear and the cytoplasmic fractions of L929 cells; their concentration was 3-fold higher in the former fraction. Ornithine decarboxylase activity was only found in the cytoplasm, and this activity could be stimulated in enucleated cells by the addition of fresh medium. These cells synthesized putrescine actively, but the putrescine made was not converted to spermidine, and accumulated to relatively high concentrations. Similarly, methionine did not act as a precursor to spermidine in enucleated cells, in contrast to whole cells, although it was incorporated into cell protein. Spermidine synthesis, unlike putrescine synthesis, appears to be completely dependent on a nuclear component.
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PMID:Polyamine metabolism in enucleated mouse L-cells. 56 8

Ornithine decarboxylase (L-ornithine carboxy-lase, EC 4.1.1.17) and S-adenosyl-methionine decarboxylase (S-adenosyl-L-methionine carboxy-lase, EC 4.1.1.50) were assayed in Drosophilia melanogaster larvae. The highest enzyme activities were detected in 24 and 48 h larvae, with diminishing activities in subsequent larval stages. Stimulation of S-adenosylmethionine decarboxylase by putrescine was demonstrable in late but not in early stages of larval development.
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PMID:Decarboxylases for polyamine biosynthesis in Drosophila melanogaster larvae. 81 11

A comparison was made between rats fed diets containing either 5% casein or 25% casein, both being supplemented with DL-methionine, from the first day of pregnancy. Livers of dams killed on days 7, 14, and 21 and whole fetuses on days 12, 14, and 21 were weighed, analyzed for protein, RNA and DNA content and assayed for ornithine decarboxylase (ODC) and S-adenosyl-L-methionine decarboxylase (SAMD). Free and total alkaline ribonuclease activity were also measured in the maternal livers. Malnutrition reduced the characteristic increase in content of DNA, RNA and protein in the maternal liver and fetus. In control rats total hepatic RNase activity increased and free RNase activity decreased during late pregnancy. In the deprived group, total activity decreased and free activity increased during late pregnancy. Liver and fetal ODC and SAMD activities were reduced by undernutrition. These studies show that malnutrition reduced both growth and the accretion of RNA in livers and fetuses of rat dams. These changes coincide with a reduced activity of polyamine synthesizing enzymes suggesting that there is a functional relationship between polyamines and RNA. High hepatic free RNase activity in malnourished dams may help to limit any build up in RNA content.
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PMID:Effects of malnutrition on some aspects of RNA metabolism in the maternal liver and fetal tissues at different stages of pregnancy in the rat. 89 66

DL-alpha-Hydrazino-delta-aminovaleric acid (DL-HAVA) is a potent and fairly specific inhibitor of ornithine decarboxylase (EC 4.1.1.17). Its effect on polyamine metabolism and cell proliferation was investigated in sarcoma-180, inoculated into the axillary region of mice. In the tumor tissues, the activities of ornithine and S-adenosyl-L-methionine decarboxylases and the putrescine level were much higher in the early stage of growth than those in normal mouse liver. Administration of DL-HAVA greatly depressed the putrescine level and putrescine formation from L-ornithine. It also suppressed DNA synthesis and increase in weight of the tumor tissue. However, it had little effect on RNA synthesis or the tissue concentration of spermidine and spermine. The inhibition of DNA synthesis and subsequent tumor development by DL-HAVA was effectively prevented by putrescine, but not by cadaverine or 1,7-diaminoheptane. From these results it is concluded that the suppression of DNA synthesis and neoplastic growth by DL-HAVA is due to decrease in the putrescine level by inhibition of ornithine decarboxylase.
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PMID:Effect of DL-alpha-hydrazino-delta-aminovaleric acid, an inhibitor of ornithine decarboxylase, on polyamine metabolism and growth of mouse sarcoma-180. 102 52

Expression of the Trypanosoma brucei ornithine decarboxylase (ODC) gene in Escherichia coli behind the lambda phage PR promoter led to the production of a recombinant enzyme having the same subunit molecular weight as the native enzyme [4]. However, when the same gene is expressed behind the tac promoter or the phoA promoter, the ODCs produced by the transformed E. coli have subunit molecular weights approximately 2 kDa higher than that of the native enzyme. Amino terminal sequencing of the recombinant proteins indicates that the ODC synthesized under control of the lambda PR promoter actually starts at the second methionine (Met23) of the open reading frame, whereas those produced in the latter two cases begin at the first methionine (Met1). Analysis of the 5'-end of T. brucei ODC mRNA supports the conclusion that translation initiates at Met23. We postulate that, for the lambda PR promoter, translation initiates at Met23 instead of Met1 because of the formation of a stable secondary structure in the region of the Met1 and the presence of a good E. coli consensus translation initiation site upstream of Met23. We have constructed a new plasmid using the pho A promoter to express recombinant T. brucei ODC starting at Met23 in large quantities.
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PMID:The translation initiation site of recombinant Trypanosoma brucei ornithine decarboxylase varies with different promoters. 143 79

Ornithine decarboxylase (ODC), which initiates the biosynthesis of the polyamines putrescine, spermidine, and spermine, is encoded by the spe-1 gene of the fungus Neurospora crassa. This gene and its cDNA have been cloned and sequenced. The gene has a single 70-nucleotide intron in the coding sequence. The cDNA, comprising the entire coding region, recognizes a single 2.4-kb mRNA in Northern (RNA) blots. The mRNA transcript, defined by S1 mapping, has an extremely long, 535-base leader without strong secondary-structure features or an upstream reading frame. The translational start of the protein is ambiguous: a Met-Val-Met sequence precedes the Pro known to be the N terminus of the ODC polypeptide. The polypeptide encoded by the N. crassa spe-1 gene (484 amino acids) has 46% amino acid identity with that of Saccharomyces cerevisiae (466 amino acids) and 42% with that of mouse (461 amino acids). Alignment of the longer N. crassa sequence with S. cerevisiae and mouse sequences creates gaps in different sites in the S. cerevisiae and mouse sequences, suggesting that N. crassa ODC is closer to an ancestral form of the enzyme than that of either yeast or mouse ODC. N. crassa ODC, which turns over rapidly in vivo in the presence of polyamines, has two PEST sequences, found in most ODCs and other proteins with rapid turnover. In striking contrast to other eucaryotic organisms, the variation in the rate of ODC synthesis in response to polyamines in N. crassa is largely correlated with proportional changes in the abundance of ODC mRNA. Spermidine is the main effector of repression, while putrescine has a weaker effect. However, putrescine accumulation appears to increase the amount of active ODC that is made from a given amount of ODC mRNA, possibly by improving its translatability. Conversely, prolonged starvation for both putrescine and spermidine leads to the differentially impaired translation of ODC mRNA.
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PMID:Ornithine decarboxylase gene of Neurospora crassa: isolation, sequence, and polyamine-mediated regulation of its mRNA. 153 Aug 78

We have developed a clonal variant, named DF-40, from the N2a mouse neuroblastoma cell line, which has the ornithine decarboxylase (L-ornithine carboxylase, EC 4.1.1.17, ODC) gene amplified. When DF-40 cells were maintained in a simple salt glucose medium (e.g. Earle's blanced salt solution), L-asparagine alone was sufficient to induce a maximal increase in ODC activity. The increase in ODC activity correlated well with an increase in the amount of ODC protein. Northern blot analysis indicated that asparagine caused a 12-15-fold increase in ODC mRNA. The half-life of ODC mRNA induced by asparagine in DF-40 cells changed from more than 8 h to about 25 min upon removal of asparagine from the culture in the presence of actinomycin D. In contrast, asparagine had little or no effect on the rate of transcription of the ODC gene. Pulse labeling of cells for 15 min with [35S]methionine showed a 90-140-fold increase in the synthesis of ODC protein after 4-8 h of incubation with asparagine. The removal of asparagine from the medium resulted in a rapid loss of ODC protein with a half-life as short as 12 min. The presence of asparagine increased the half-life of ODC protein by 3-5-fold when measured in the presence of cycloheximide. Taken together, our data show that asparagine induced ODC gene expression in DF-40 cells, primarily by post-transcriptional stabilization of ODC mRNA. In addition, asparagine specifically stimulated the synthesis and suppressed the degradation of ODC protein.
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PMID:Mechanism of regulation of ornithine decarboxylase gene expression by asparagine in a variant mouse neuroblastoma cell line. 155 4

Young rainbow trout were given diets containing graded levels of methionine for 16 wk. Analysis of the weight gain and food efficiency data showed the methionine requirement to be not more than 0.76% of the diet (1.9% of dietary protein). Activities of regulatory enzymes of the transulfuration pathway, methionine adenosyltransferase and cystathionine synthase in trout liver were not altered by changes in methionine intake. Concentrations of free serine in liver and plasma of the trout were high at low levels of methionine intake but fell as dietary methionine increased. This implied decreased flux through cystathionine synthase at low methionine intakes. Large increases in liver and plasma taurine occurred at high methionine intakes, implying enhanced transulfuration activity. Liver ornithine decarboxylase activity was reduced at the lowest level of dietary methionine used but the activity of S-adenosylmethionine decarboxylase was unchanged. Eye lenses of the trout given these diets were examined by a scanning lens monitor. Analysis of focal length variability with this equipment demonstrated that, if abnormality of the lens is to be avoided, a higher concentration of dietary methionine (0.96% or 0.6% methionine + 0.36% cystine) is needed than that required to maximize growth.
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PMID:Methionine intake in rainbow trout (Oncorhynchus mykiss), relationship to cataract formation and the metabolism of methionine. 156 69


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