Rapid and regulated degradation of ornithine decarboxylase

Hayashi, S.; Murakami, Yasuko

doi:10.1042/bj3060001

Cited by 194 publications

(140 citation statements)

References 150 publications

(168 reference statements)

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“…A similar type of induction of both polyamine uptake (reviewed in [5]) and ODC activity (reviewed in [25]) can be observed in mammalian cells in response to various growth stimuli. In mammalian cells one type of regulation of both ODC and polyamine transport activity involves a small labile protein called antizyme (reviewed in [26]). Although it is not known whether T. cruzi contains antizyme, T. b. brucei does not seem to contain this protein [27].…”

Section: Discussionmentioning

confidence: 99%

Regulation of a high-affinity diamine transport system in Trypanosoma cruzi epimastigotes

Quesne

Fairlamb

1996

Biochemical Journal

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Trypanosoma cruzi epimastigotes take up exogenous [3H]putrescine and [3H]cadaverine by a rapid, high-affinity, transport system that exhibits saturable kinetics (putrescine Km 2.0 μM, Vmax 3.3 nmol/min per 108 cells; cadaverine Km 13.4 μM, Vmax 3.9 nmol/min per 108 cells). Putrescine transport is temperature dependent and requires the presence of a membrane potential and thiol groups for activity. Its activity is altered in response to extracellular putrescine levels and as the cells proceed through the growth cycle. This transporter shows high specificity for the diamines putrescine and cadaverine, but low specificity for the polyamines spermidine and spermine. The existence of rapid diamine/polyamine transport systems whose activity can be adjusted in response to the growth conditions is of particular importance, as they seem unable to synthesize their own putrescine [Hunter, Le Quesne and Fairlamb (1994) Eur. J. Biochem. 226, 1019–1027].

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Section: Discussionmentioning

confidence: 99%

Regulation of a high-affinity diamine transport system in Trypanosoma cruzi epimastigotes

Quesne

Fairlamb

1996

Biochemical Journal

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“…2, SSAT was degraded very rapidly by these lysates, and the loss of the SSAT band occurred at a rate comparable to that of ODC. A maximal rate of ODC degradation required the addition of antizyme, which is known to be present in limited amounts in reticulocyte lysates (26), whereas antizyme had no effect on the rate of loss of SSAT.…”

Section: Degradation Of Ssat and Odc In An Atp-dependent Reticu-mentioning

confidence: 99%

“…The turnover of ODC, which is mediated by a polyamine-inducible protein termed antizyme, has been studied extensively (25)(26)(27)(28)(29), but there is no published information available on the mechanism of degradation of S-adenosylmethionine decarboxylase and SSAT.…”

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confidence: 99%

Proteasomal Degradation of Spermidine/Spermine N 1-Acetyltransferase Requires the Carboxyl-terminal Glutamic Acid Residues

Coleman¹,

Pegg

1997

Journal of Biological Chemistry

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The rapid turnover of spermidine/spermine N 1 -acetyltransferase (SSAT), a key enzyme in the regulation of polyamine levels, was found to be mediated via ubiquitination and the proteasomal system. SSAT degradation was blocked by the binding of polyamines or of the polyamine analog, N 1 ,N 12 -bis(ethyl)spermine (BE-3-4-3), to the protein, providing a mechanism for the increase of SSAT activity in response to these agents. Site-directed mutagenesis indicated that a number of residues including arginine 19, cysteine 122, histidine 126, glutamic acid 152, arginine 155, and methionine 167 were needed for protection of SSAT by BE-3-4-3. These residues have previously been shown to reduce the affinity for the binding of polyamines to the SSAT protein, and these results indicate that the change in protein configuration brought about by this binding renders the protein resistant to proteasomal degradation. Mutations to alanines of residues arginine 7, cysteine 14, and lysine 141 also prevented the protection by BE-3-4-3, and these residues may be required for the formation of the protected conformation. The rapid degradation of SSAT required the carboxyl-terminal region of the protein, and the two terminal glutamic acid residues at positions 170 and 171 were found to be of critical importance. Truncation of the protein to remove these residues or the mutation of either of these acidic residues to glutamine completely abolished the rapid degradation of SSAT. The addition of two extra lysine residues at the carboxyl terminus or the conversion of the glutamic acids at positions 170 and 171 to lysines also prevented SSAT degradation by the proteasome. These results show the key role of the acidic residues at the carboxyl terminus of the protein in reacting with the proteasome. In contrast, mutation of lysine 166 to alanine, which extends the length of the acidic region in the carboxyl-terminal fragment of SSAT, actually increased the rate of degradation of SSAT without affecting its stabilization by BE-3-4-3. The binding of BE-3-4-3 or polyamines is therefore likely to change the configuration of the SSAT protein in a way that prevents the exposure of the carboxyl-terminal region of the ubiquitinated protein to the proteasome.Spermidine/spermine N 1 -acetyltransferase (SSAT), 1 which converts spermidine and spermine into their N 1 -acetyl derivatives, is an important enzyme in mammalian cells that prevents the overaccumulation of polyamines by facilitating their excretion and degradation (1-3). Alterations in SSAT activity are brought about by changes in amount of enzyme protein (4, 5), and the enzyme is highly inducible by a variety of hormones, physiological stimuli, drugs, and toxic agents. It is also strongly induced by polyamines, and it has been suggested that a rise in the free polyamine content is an intermediary in the induction by other agents (6). The most potent inducers of SSAT are polyamine analogs that have substitutions on the terminal nitrogens and, therefore, are not substrates for acetylation (1,(7)(8)(9)...

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“…ODC has also been directly implicated in the c-myc-mediated accelerated cell death of IL-3 deprived, c-myc overexpressing cell lines [10]. Activity of ODC is regulated at the transcriptional, translational and post-translational levels and polyamine feedback repression is mediated by an ODC antizyme [2,11].…”

Section: Introductionmentioning

confidence: 99%

Molecular cloning and functional identification of a plant ornithine decarboxylase cDNA

Michael

Furze

Rhodes

et al. 1996

Biochemical Journal

125

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A cDNA for a plant ornithine decarboxylase (ODC), a key enzyme in putrescine and polyamine biosynthesis, has been isolated from root cultures of the solanaceous plant Datura stramonium. Reverse transcription–PCR employing degenerate oligonucleotide primers representing conserved motifs from other eukaryotic ODCs was used to isolate the cDNA. The longest open reading frame potentially encodes a peptide of 431 amino acids and exhibits similarity to other eukaryotic ODCs, prokaryotic and eukaryotic arginine decarboxylases (ADCs), prokaryotic meso-diaminopimelate decarboxylases and the product of the tabA gene of Pseudomonas syringae cv. tabaci. Residues involved at the active site of the mouse ODC are conserved in the plant enzyme. The plant ODC does not possess the C-terminal extension found in the mammalian enzyme, implicated in rapid turnover of the protein, suggesting that the plant ODC may have a longer half-life. Expression of the plant ODC in Escherichia coli and demonstration of ODC activity confirmed that the cDNA encodes an active ODC enzyme. This is the first description of the primary structure of a eukaryotic ODC isolated from an organism where the alternative ADC route to putrescine is present.

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Rapid and regulated degradation of ornithine decarboxylase

Cited by 194 publications

References 150 publications

Regulation of a high-affinity diamine transport system in Trypanosoma cruzi epimastigotes

Regulation of a high-affinity diamine transport system in Trypanosoma cruzi epimastigotes

Proteasomal Degradation of Spermidine/Spermine N 1-Acetyltransferase Requires the Carboxyl-terminal Glutamic Acid Residues

Molecular cloning and functional identification of a plant ornithine decarboxylase cDNA

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