Статті в журналах: "Ornithine Acetyltransferase"

1

Hao, Ning, Jingrui Mu, Nan Hu, Sheng Xu, Peng Shen, Ming Yan, Yan Li, and Lin Xu. "Implication of ornithine acetyltransferase activity onl-ornithine production inCorynebacterium glutamicum." Biotechnology and Applied Biochemistry 63, no. 1 (August 13, 2015): 15–21. http://dx.doi.org/10.1002/bab.1353.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

2

Halmekytö, M., J. M. Hyttinen, R. Sinervirta, P. Leppänen, J. Jänne, and L. Alhonen. "Regulation of the expression of human ornithine decarboxylase gene and ornithine decarboxylase promoter-driven reporter gene in transgenic mice." Biochemical Journal 292, no. 3 (June 15, 1993): 927–32. http://dx.doi.org/10.1042/bj2920927.

Повний текст джерела

Анотація:

We have studied the regulation of the expression of ornithine decarboxylase with the aid of transgenic mice harbouring either functional human ornithine decarboxylase genes or the mouse ornithine decarboxylase promoter-driven chloramphenicol acetyltransferase fusion gene in their genome. We used three different stimuli which are well known to enhance ornithine decarboxylase activity in their appropriate target tissues: (i) testosterone in female kidney, (ii) a phorbol ester in epidermis and (iii) partial hepatectomy in liver. Endogenous mouse ornithine decarboxylase activity was strikingly stimulated in response to these treatments. Even though containing the 5′ flanking region of the mouse ornithine decarboxylase gene, known to possess full promoter activity, the chloramphenicol acetyltransferase reporter gene was entirely insensitive to any of these stimuli. The human transgene-derived ornithine decarboxylase activity in kidney was unaffected by testosterone treatment, but responded in skin to application of the phorbol ester and likewise was clearly enhanced in regenerating liver. Although mouse endogenous ornithine decarboxylase mRNA levels were distinctly elevated after testosterone, this treatment did not influence the accumulation of the human transgene-derived mRNA. The phorbol ester enhanced the accumulation of mouse endogenous ornithine decarboxylase mRNA and also that derived from the human transgene; however, the enzyme activity was stimulated in regenerating liver without appreciable changes in the levels of endogenous or transgene-derived message. Our present results strongly emphasize the central role of the coding sequence or ornithine decarboxylase gene in the induction of the enzyme activity.

Стилі APA, Harvard, Vancouver, ISO та ін.

3

Desiderio, M. A., S. Mattei, G. Biondi, and M. P. Colombo. "Cytosolic and nuclear spermidine acetyltransferases in growing NIH 3T3 fibroblasts stimulated with serum or polyamines: relationship to polyamine-biosynthetic decarboxylases and histone acetyltransferase." Biochemical Journal 293, no. 2 (July 15, 1993): 475–79. http://dx.doi.org/10.1042/bj2930475.

Повний текст джерела

Анотація:

The expression (mRNA level of enzymic activity) of cytosolic and nuclear spermidine acetyltransferases was studied in NIH 3T3 fibroblasts, either (1) serum-starved and stimulated to grow by serum refeeding, or (2) treated with inhibitors of ornithine decarboxylase (ODC) (MDL 72.175) and S-adenosylmethionine decarboxylase (AdoMetDC) (MDL 73.811) and stimulated to grow by spermidine. Expression of the known growth-regulated genes for ODC, AdoMetDC and histone acetyltransferase was also examined. The mRNA for spermidine/spermine N1-acetyltransferase (SAT) accumulated after serum refeeding (between 6 and 16 h) and even more after spermidine addition (16 h). Histone acetyltransferase activity increased after both growth stimuli, whereas spermidine N8-acetyltransferase activity remained unchanged. After serum stimulation, the ODC mRNA level and activity rose between 6 and 16 h, whereas AdoMetDC mRNA accumulation occurred later (16 h) than the increase in enzyme activity (6 h). Stimulation of ODC and AdoMetDC activities was suppressed by the inhibitors added alone or in combination with spermidine, whereas mRNA accumulation was down-regulated by spermidine. These results indicate that the expression of SAT was growth-controlled and that SAT mRNA level was regulated by polyamines.

Стилі APA, Harvard, Vancouver, ISO та ін.

4

Seidel, E. R., and R. G. Snyder. "Pentagastrin induction of spermine/spermidine N1-acetyltransferase and mucosal polyamines." American Journal of Physiology-Gastrointestinal and Liver Physiology 256, no. 1 (January 1, 1989): G16—G21. http://dx.doi.org/10.1152/ajpgi.1989.256.1.g16.

Повний текст джерела

Анотація:

The trophic response of the gastrointestinal mucosa to treatment with the hormone gastrin includes a polyamine-dependent step. Because gastrin does not induce ornithine decarboxylase, experiments were designed to determine whether pentagastrin induced the polyamine interconverting enzyme, spermine/spermidine N1-acetyltransferase (SAT). Eight hours after intraperitoneal treatment of rats with either spermidine (0.8 mmol/kg) or pentagastrin (250 micrograms/kg) oxyntic gland mucosal SAT activity was increased from roughly 400 to 800 pmol [14C]acetate.mg protein-1.h-1. In contrast, colonic mucosa was not sensitive to pentagastrin even though spermidine treatment induced nearly a 400% increase in SAT activity. Measurement of both oxyntic gland and colonic mucosal polyamine concentrations showed that by 16 h after pentagastrin (250 micrograms/kg ip) putrescine, acetylspermidine, and spermidine levels all were increased to a level approximately 200% of that observed in NaCl-treated rats. By 24 h mucosal polyamine content of pentagastrin-treated rats was not different from control. Essentially the same results were found in animals treated with difluoromethylornithine, thus demonstrating that the increase in mucosal polyamine concentration was not related to the induction of ornithine decarboxylase. The results of these experiments demonstrate that unlike most hormones, the hormone gastrin induces the polyamine converting enzyme, SAT, rather than ornithine decarboxylase during stimulation of polyamine-dependent cell growth and/or division.

Стилі APA, Harvard, Vancouver, ISO та ін.

5

Liu, Yongshu, Robyn Heeswijck, Peter Hoj, and Nicholas Hoogenraad. "Purification and Characterization of Ornithine Acetyltransferase from Saccharomyces cerevisiae." European Journal of Biochemistry 228, no. 2 (March 1995): 291–96. http://dx.doi.org/10.1111/j.1432-1033.1995.tb20262.x.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

6

Sankaranarayanan, Ramasamy, Maia M. Cherney, Craig Garen, Grace Garen, Chunying Niu, Marshall Yuan, and Michael N. G. James. "The Molecular Structure of Ornithine Acetyltransferase from Mycobacterium tuberculosis Bound to Ornithine, a Competitive Inhibitor." Journal of Molecular Biology 397, no. 4 (April 2010): 979–90. http://dx.doi.org/10.1016/j.jmb.2010.02.018.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

7

Xu, Ying, Bernard Labedan, and Nicolas Glansdorff. "Surprising Arginine Biosynthesis: a Reappraisal of the Enzymology and Evolution of the Pathway in Microorganisms." Microbiology and Molecular Biology Reviews 71, no. 1 (March 2007): 36–47. http://dx.doi.org/10.1128/mmbr.00032-06.

Повний текст джерела

Анотація:

SUMMARY Major aspects of the pathway of de novo arginine biosynthesis via acetylated intermediates in microorganisms must be revised in light of recent enzymatic and genomic investigations. The enzyme N-acetylglutamate synthase (NAGS), which used to be considered responsible for the first committed step of the pathway, is present in a limited number of bacterial phyla only and is absent from Archaea. In many Bacteria, shorter proteins related to the Gcn5-related N-acetyltransferase family appear to acetylate l-glutamate; some are clearly similar to the C-terminal, acetyl-coenzyme A (CoA) binding domain of classical NAGS, while others are more distantly related. Short NAGSs can be single gene products, as in Mycobacterium spp. and Thermus spp., or fused to the enzyme catalyzing the last step of the pathway (argininosuccinase), as in members of the Alteromonas-Vibrio group. How these proteins bind glutamate remains to be determined. In some Bacteria, a bifunctional ornithine acetyltransferase (i.e., using both acetylornithine and acetyl-CoA as donors of the acetyl group) accounts for glutamate acetylation. In many Archaea, the enzyme responsible for glutamate acetylation remains elusive, but possible connections with a novel lysine biosynthetic pathway arose recently from genomic investigations. In some Proteobacteria (notably Xanthomonadaceae) and Bacteroidetes, the carbamoylation step of the pathway appears to involve N-acetylornithine or N-succinylornithine rather than ornithine. The product N-acetylcitrulline is deacetylated by an enzyme that is also involved in the provision of ornithine from acetylornithine; this is an important metabolic function, as ornithine itself can become essential as a source of other metabolites. This review insists on the biochemical and evolutionary implications of these findings.

Стилі APA, Harvard, Vancouver, ISO та ін.

8

Dietl, Anna-Maria, Ulrike Binder, Ingo Bauer, Yana Shadkchan, Nir Osherov, and Hubertus Haas. "Arginine Auxotrophy Affects Siderophore Biosynthesis and Attenuates Virulence of Aspergillus fumigatus." Genes 11, no. 4 (April 15, 2020): 423. http://dx.doi.org/10.3390/genes11040423.

Повний текст джерела

Анотація:

Aspergillus fumigatus is an opportunistic human pathogen mainly infecting immunocompromised patients. The aim of this study was to characterize the role of arginine biosynthesis in virulence of A. fumigatus via genetic inactivation of two key arginine biosynthetic enzymes, the bifunctional acetylglutamate synthase/ornithine acetyltransferase (argJ/AFUA_5G08120) and the ornithine carbamoyltransferase (argB/AFUA_4G07190). Arginine biosynthesis is intimately linked to the biosynthesis of ornithine, a precursor for siderophore production that has previously been shown to be essential for virulence in A. fumigatus. ArgJ is of particular interest as it is the only arginine biosynthetic enzyme lacking mammalian homologs. Inactivation of either ArgJ or ArgB resulted in arginine auxotrophy. Lack of ArgJ, which is essential for mitochondrial ornithine biosynthesis, significantly decreased siderophore production during limited arginine supply with glutamine as nitrogen source, but not with arginine as sole nitrogen source. In contrast, siderophore production reached wild-type levels under both growth conditions in ArgB null strains. These data indicate that siderophore biosynthesis is mainly fueled by mitochondrial ornithine production during limited arginine availability, but by cytosolic ornithine production during high arginine availability via cytosolic arginine hydrolysis. Lack of ArgJ or ArgB attenuated virulence of A. fumigatus in the insect model Galleria mellonella and in murine models for invasive aspergillosis, indicating limited arginine availability in the investigated host niches.

Стилі APA, Harvard, Vancouver, ISO та ін.

9

Pegg, A. E., and D. J. Feith. "Polyamines and neoplastic growth." Biochemical Society Transactions 35, no. 2 (March 20, 2007): 295–99. http://dx.doi.org/10.1042/bst0350295.

Повний текст джерела

Анотація:

Studies over many years have suggested that increased polyamine synthesis may be necessary for neoplastic growth. This review summarizes recent work on the regulation of putrescine production both de novo and via the degradation of higher polyamines and provides a summary of studies using transgenic mice in which the levels of proteins that regulate these processes (L-ornithine decarboxylase, antizyme and spermidine/spermine-N1-acetyltransferase) are altered.

Стилі APA, Harvard, Vancouver, ISO та ін.

10

Sankaranarayanan, R., C. R. Garen, M. M. Cherney, M. Yuan, C. Lee, and M. N. G. James. "Preliminary X-ray crystallographic analysis of ornithine acetyltransferase (Rv1653) fromMycobacterium tuberculosis." Acta Crystallographica Section F Structural Biology and Crystallization Communications 65, no. 2 (January 31, 2009): 173–76. http://dx.doi.org/10.1107/s1744309109000360.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

11

Hao, N., Mu, N. Hu, S. Xu, M. Yan, Y. Li, K. Guo, and L. Xu. "Improvement of l-citrulline production in Corynebacterium glutamicum by ornithine acetyltransferase." Journal of Industrial Microbiology & Biotechnology 42, no. 2 (December 10, 2014): 307–13. http://dx.doi.org/10.1007/s10295-014-1561-x.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

12

Deignan, Joshua L., Justin C. Livesay, Lisa M. Shantz, Anthony E. Pegg, William E. O'Brien, Ramaswamy K. Iyer, Stephen D. Cederbaum, and Wayne W. Grody. "Polyamine homeostasis in arginase knockout mice." American Journal of Physiology-Cell Physiology 293, no. 4 (October 2007): C1296—C1301. http://dx.doi.org/10.1152/ajpcell.00393.2006.

Повний текст джерела

Анотація:

The role of ornithine decarboxylase (ODC) in polyamine metabolism has long been established, but the exact source of ornithine has always been unclear. The arginase enzymes are capable of producing ornithine for the production of polyamines and may hold important regulatory functions in the maintenance of this pathway. Utilizing our unique set of arginase single and double knockout mice, we analyzed polyamine levels in the livers, brains, kidneys, and small intestines of the mice at 2 wk of age, the latest timepoint at which all of them are still alive, to determine whether tissue polyamine levels were altered in response to a disruption of arginase I (AI) and II (AII) enzymatic activity. Whereas putrescine was minimally increased in the liver and kidneys from the AII knockout mice, spermidine and spermine were maintained. ODC activity was not greatly altered in the knockout animals and did not correlate with the fluctuations in putrescine. mRNA levels of ornithine aminotransferase (OAT), antizyme 1 (AZ1), and spermidine/spermine- N1-acetyltransferase (SSAT) were also measured and only minor alterations were seen, most notably an increase in OAT expression seen in the liver of AI knockout and double knockout mice. It appears that putrescine catabolism may be affected in the liver when AI is disrupted and ornithine levels are highly reduced. These results suggest that endogenous arginase-derived ornithine may not directly contribute to polyamine homeostasis in mice. Alternate sources such as diet may provide sufficient polyamines for maintenance in mammalian tissues.

Стилі APA, Harvard, Vancouver, ISO та ін.

13

Xu, Ying, Ziyuan Liang, Christianne Legrain, Hans J. Rüger та Nicolas Glansdorff. "Evolution of Arginine Biosynthesis in the Bacterial Domain: Novel Gene-Enzyme Relationships from Psychrophilic Moritella Strains (Vibrionaceae) and Evolutionary Significance of N-α-Acetyl Ornithinase". Journal of Bacteriology 182, № 6 (15 березня 2000): 1609–15. http://dx.doi.org/10.1128/jb.182.6.1609-1615.2000.

Повний текст джерела

Анотація:

ABSTRACT In the arginine biosynthetic pathway of the vast majority of prokaryotes, the formation of ornithine is catalyzed by an enzyme transferring the acetyl group of N-α-acetylornithine to glutamate (ornithine acetyltransferase [OATase]) (argJencoded). Only two exceptions had been reported—theEnterobacteriaceae and Myxococcus xanthus(members of the γ and δ groups of the classProteobacteria, respectively)—in which ornithine is produced from N-α-acetylornithine by a deacylase, acetylornithinase (AOase) (argE encoded). We have investigated the gene-enzyme relationship in the arginine regulons of two psychrophilic Moritella strains belonging to theVibrionaceae, a family phylogenetically related to theEnterobacteriaceae. Most of the arg genes were found to be clustered in one continuous sequence divergently transcribed in two wings, argE and argCBFGH(A)[“H(A)” indicates that the argininosuccinase gene consists of a part homologous to known argH sequences and of a 3′ extension able to complement an Escherichia colimutant deficient in the argA gene, encodingN-α-acetylglutamate synthetase, the first enzyme committed to the pathway]. Phylogenetic evidence suggests that this new clustering pattern arose in an ancestor common toVibrionaceae and Enterobacteriaceae, where OATase was lost and replaced by a deacylase. The AOase and ornithine carbamoyltransferase of these psychrophilic strains both display distinctly cold-adapted activity profiles, providing the first cold-active examples of such enzymes.

Стилі APA, Harvard, Vancouver, ISO та ін.

14

Bettuzzi, Saverio, Paola Strocchi, Pierpaola Davalli, Maria Marinelli, Luciana Furci, and Arnaldo Corti. "Androgen responsiveness and intrarenal localization of transcripts coding for the enzymes of polyamine metabolism in the mouse." Biochemistry and Cell Biology 79, no. 2 (April 1, 2001): 133–40. http://dx.doi.org/10.1139/o01-001.

Повний текст джерела

Анотація:

Polyamines, spermidine (SPD), and spermine (SPM) are intracellular polycations required for cell growth and differentiation. Their biosynthetic precursor, the diamine putrescine (PUT), is produced by regulatory ornithine decarboxylase (ODC). Spermidine/spermine N1-acetyltransferase (SSAT) is the ODC counterpart in the degradation pathway which retroconverts SPM and SPD into PUT. Castration of male mice for 7 days resulted in a 40% decrease of the renal levels of both SSAT and ODC transcripts. Administration of 5-α-dihydrotestosterone (DHT) to castrated mice for the last 3 days before sacrifice caused the levels of ODC and SSAT mRNAs to increase by 250% and 180%, respectively. Thus activation of the retroconversion pathway of polyamine metabolism appears to contribute towards the increase in PUT production known to be caused by androgens in the mouse kidney. In situ hybridization histochemistry experiments showed that the SSAT transcript is expressed only by the epithelial cells of the straight and convoluted distal tubules of the nephron, while the expression of the ODC transcript is confined to the epithelium of the convoluted and straight portion of the proximal tubules. The separation of the biosynthetic from the degradation pathway along the nephron suggests that PUT is mostly produced in the distal tubule, where it may play a physiological role, independent of androgen action, in protecting tubular cells from the very low osmolarity to which they are exposed in this nephron segment.Key words: Adenosylmethionine decarboxylase, spermidine/spermine N1-acetyltransferase, ornithine decarboxylase, mouse kidney, polyamines.

Стилі APA, Harvard, Vancouver, ISO та ін.

15

Abadjieva, Agnes, Pierre Hilven, Katia Pauwels, and Marjolaine Crabeel. "The YeastARG7Gene Product Is Autoproteolyzed to Two Subunit Peptides, Yielding Active Ornithine Acetyltransferase." Journal of Biological Chemistry 275, no. 15 (April 6, 2000): 11361–67. http://dx.doi.org/10.1074/jbc.275.15.11361.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

16

Tahlan, Kapil, Hyeon Ung Park, Annie Wong, Perrin H. Beatty, and Susan E. Jensen. "Two Sets of Paralogous Genes Encode the Enzymes Involved in the Early Stages of Clavulanic Acid and Clavam Metabolite Biosynthesis in Streptomyces clavuligerus." Antimicrobial Agents and Chemotherapy 48, no. 3 (March 2004): 930–39. http://dx.doi.org/10.1128/aac.48.3.930-939.2004.

Повний текст джерела

Анотація:

ABSTRACT Recently, a second copy of a gene encoding proclavaminate amidinohydrolase (pah1), an enzyme involved in the early stages of clavulanic acid and clavam metabolite biosynthesis in Streptomyces clavuligerus, was identified and isolated. Using Southern analysis, we have now isolated second copies of the genes encoding the carboxyethylarginine synthase (ceaS) and β-lactam synthetase (bls) enzymes. These new paralogues are given the gene designations ceaS1 and bls1 and are located immediately upstream of pah1 on the chromosome. Furthermore, sequence analysis of the region downstream of pah1 revealed a second copy of a gene encoding ornithine acetyltransferase (oat1), thus indicating the presence of a cluster of paralogue genes. ceaS1, bls1, and oat1 display 73, 60, and 63% identities, respectively, at the nucleotide level to the original ceaS2, bls2, and oat2 genes from the clavulanic acid gene cluster. Single mutants defective in ceaS1, bls1, or oat1 were prepared and characterized and were found to be affected to variable degrees in their ability to produce clavulanic acid and clavam metabolites. Double mutants defective in both copies of the genes were also prepared and tested. The ceaS1/ceaS2 and the bls1/bls2 mutant strains were completely blocked in clavulanic acid and clavam metabolite biosynthesis. On the other hand, oat1/oat2 double mutants still produced some clavulanic acid and clavam metabolites. This may be attributed to the presence of the argJ gene in S. clavuligerus, which encodes yet another ornithine acetyltransferase enzyme that may be able to compensate for the lack of OAT1 and -2 in the double mutants.

Стилі APA, Harvard, Vancouver, ISO та ін.

17

Fuller, D. J. M., S. W. Carper, L. Clay, J. R. Chen, and E. W. Gerner. "Polyamine regulation of heat-shock-induced spermidine N1-acetyltransferase activity." Biochemical Journal 267, no. 3 (May 1, 1990): 601–5. http://dx.doi.org/10.1042/bj2670601.

Повний текст джерела

Анотація:

The enzyme spermidine/spermine N1-acetyltransferase (N1-SAT) is rapidly induced by heat shock in CHO and A549 cells, with activity declining by 24 h. Depletion of intracellular polyamines by alpha-difluoromethylornithine, an inhibitor of ornithine decarboxylase, blocks this induction. Re-addition of putrescine to these cultures restores the response to heat shock, with a concomitant increase in intracellular N1-acetylspermidine. Diaminopropane is more than twice as effective as the naturally occurring diamine putrescine, suggesting that the propylamine moiety of spermidine is involved in the regulation of N1-SAT induction. Inhibitor studies indicate transcriptional activation and that the enzyme has an apparent half-life of 30-60 min. A second heat shock rapidly inhibits induced N1-SAT activity, which decays with a half-life of 2-3 min. Despite its induction by heat, N1-SAT is not a stable enzyme, suggesting that the activity observed is not due to a modification of an existing peptide, but is due to a transcriptional event, which may justify the inclusion of this enzyme in the family of heat-shock proteins.

Стилі APA, Harvard, Vancouver, ISO та ін.

18

Maes, Dominique, Marjolaine Crabeel, Cécile Van de Weerdt, Joseph Martial, Eveline Peeters, Daniël Charlier, Klaas Decanniere, Celine Vanhee, Lode Wyns, and Ingrid Zegers. "Crystallization of ornithine acetyltransferase from yeast by counter-diffusion and preliminary X-ray study." Acta Crystallographica Section F Structural Biology and Crystallization Communications 62, no. 12 (November 30, 2006): 1294–97. http://dx.doi.org/10.1107/s1744309106050561.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

19

Kershaw, Nadia J., Heather J. McNaughton, Kirsty S. Hewitson, Helena Hernández, John Griffin, Claire Hughes, Philip Greaves, Barry Barton, Carol V. Robinson, and Christopher J. Schofield. "ORF6 from the clavulanic acid gene cluster of Streptomyces clavuligerus has ornithine acetyltransferase activity." European Journal of Biochemistry 269, no. 8 (April 2002): 2052–59. http://dx.doi.org/10.1046/j.1432-1033.2002.02853.x.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

20

STEFANELLI, C., F. FLAMIGNI, D. CARATI, C. ROSSONI, and C. CALDARERA. "Effects of dexamethasone on spermidine N1-acetyltransferase and ornithine decarboxylase activities in rat spleen." Biochimica et Biophysica Acta (BBA) - Molecular Cell Research 930, no. 1 (August 19, 1987): 79–86. http://dx.doi.org/10.1016/0167-4889(87)90158-3.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

21

ELKINS, Jonathan M., Nadia J. KERSHAW, and Christopher J. SCHOFIELD. "X-ray crystal structure of ornithine acetyltransferase from the clavulanic acid biosynthesis gene cluster." Biochemical Journal 385, no. 2 (January 7, 2005): 565–73. http://dx.doi.org/10.1042/bj20040814.

Повний текст джерела

Анотація:

The orf6 gene from the clavulanic acid biosynthesis gene cluster encodes an OAT (ornithine acetyltransferase). Similar to other OATs the enzyme has been shown to catalyse the reversible transfer of an acetyl group from N-acetylornithine to glutamate. OATs are Ntn (N-terminal nucleophile) enzymes, but are distinct from the better-characterized Ntn hydrolase enzymes as they catalyse acetyl transfer rather than a hydrolysis reaction. In the present study, we describe the X-ray crystal structure of the OAT, corresponding to the orf6 gene product, to 2.8 Å (1 Å=0.1 nm) resolution. The larger domain of the structure consists of an αββα sandwich as in the structures of Ntn hydrolase enzymes. However, differences in the connectivity reveal that OATs belong to a structural family different from that of other structurally characterized Ntn enzymes, with one exception: unexpectedly, the αββα sandwich of ORF6 (where ORF stands for open reading frame) displays the same fold as an DmpA (L-aminopeptidase D-ala-esterase/amidase from Ochrobactrum anthropi), and so the OATs and DmpA form a new structural subfamily of Ntn enzymes. The structure reveals an α2β2-heterotetrameric oligomerization state in which the intermolecular interface partly defines the active site. Models of the enzyme–substrate complexes suggest a probable oxyanion stabilization mechanism as well as providing insight into how the enzyme binds its two differently charged substrates.

Стилі APA, Harvard, Vancouver, ISO та ін.

22

Zhao, Yue-Chao, Yu-Jing Chi, Yong-Sheng Yu, Ji-Long Liu, Ren-Wei Su, Xing-Hong Ma, Chun-Hua Shan, and Zeng-Ming Yang. "Polyamines Are Essential in Embryo Implantation: Expression and Function of Polyamine-Related Genes in Mouse Uterus during Peri-Implantation Period." Endocrinology 149, no. 5 (January 17, 2008): 2325–32. http://dx.doi.org/10.1210/en.2007-1420.

Повний текст джерела

Анотація:

Polyamines are key regulators in cell growth and differentiation. It has been shown that ornithine decarboxylase (Odc) was essential for post-implantation embryo development, and overexpression of spermidine/spermine N1-acetyltransferase will lead to ovarian hypofunction and hypoplastic uteri. However, the expression and function of polyamine-related genes in mouse uterus during early pregnancy are still unknown. In this study we investigated the expression, regulation, and function of polyamine-related genes in mouse uterus during the peri-implantation period. Odc expression was strongly detected at implantation sites and stimulated by estrogen treatment. The expression of Odc antizyme 1 and spermidine/spermine N1-acetyltransferase was also highly shown at implantation sites and regulated by Odc or polyamine level in uterine cells. Embryo implantation was significantly inhibited by α-difluoromethylornithine, an Odc inhibitor. Moreover, the reduction of Odc activity caused by α-difluoromethylornithine treatment was compensated by the up-regulation of S-adenosylmethionine decarboxylase gene expression. Collectively, our results indicated that the coordinated expression of uterine polyamine-related genes may be important for embryo implantation.

Стилі APA, Harvard, Vancouver, ISO та ін.

23

de la Fuente, A., J. F. Martín, A. Rodríguez-García, and P. Liras. "Two Proteins with Ornithine Acetyltransferase Activity Show Different Functions in Streptomyces clavuligerus: Oat2 Modulates Clavulanic Acid Biosynthesis in Response to Arginine." Journal of Bacteriology 186, no. 19 (October 1, 2004): 6501–7. http://dx.doi.org/10.1128/jb.186.19.6501-6507.2004.

Повний текст джерела

Анотація:

ABSTRACT The oat2 gene, located in the clavulanic acid gene cluster in Streptomyces clavuligerus, is similar to argJ, which encodes N-acetylornithine:glutamic acid acetyltransferase activity. Purified proteins obtained by expression in Escherichia coli of the argJ and oat2 genes of S. clavuligerus posses N-acetyltransferase activity. The kinetics and substrate specificities of both proteins are very similar. Deletion of the oat2 gene did not affect the total N-acetylornithine transferase activity and slightly reduced the formation of clavulanic acid under standard culture conditions. However, the oat2 mutant produced more clavulanic acid than the parental strain in cultures supplemented with high levels (above 1 mM) of arginine. The purified S. clavuligerus ArgR protein bound the arginine box in the oat2 promoter, and the expression of oat2 was higher in mutants with a disruption in argR (arginine-deregulated), confirming that the Arg boxes of oat2 are functional in vivo. Our results suggest that the Oat2 protein or one of its reaction products has a regulatory role that modulates clavulanic acid biosynthesis in response to high arginine concentrations.

Стилі APA, Harvard, Vancouver, ISO та ін.

24

Seiler, Nikolaus. "Functions of polyamine acetylation." Canadian Journal of Physiology and Pharmacology 65, no. 10 (October 1, 1987): 2024–35. http://dx.doi.org/10.1139/y87-317.

Повний текст джерела

Анотація:

Acetylation is a means to decrease the net positive charge of the plyamines and thus liberate polyamines from anionic binding sites. The acetyl derivatives can be removed from the cells by transport and catabolism. Intracellular polyamine metabolism can be formulated as a cyclic process, which explains the transformation of one polyamine into another. As a net result, this pathway metabolizes (in an energy-requiring manner) methionine to 5′-deoxy-5′-methylthioadenosine and β-alanine, and thus appears to be futile. It is suggested that the cyclic process is necessary for the precise control of cellular polyamine concentrations, as it allows relatively rapid spermine and spermidine concentration changes, in spite of a slow basal turnover rate. For the regulation of cellular polyamine metabolism, two decarboxylases, L-ornithine decarboxylase and S-adenosyl-L-methionine decarboxylase; the cytosolic acetyl-CoA:spermidine/spermine N1-acetyltransferase; and a polyamine transport system are required. The activity of the nucelar acetyltransferase is assumed to be the rate-limiting enzyme of nuclear polyamine turnover. The complexity and high level of sophistication of polyamine regulation is strong evidence for the important functional significance of the natural polyamines.

Стилі APA, Harvard, Vancouver, ISO та ін.

25

Martin, P. R., and M. H. Mulks. "Sequence analysis and complementation studies of the argJ gene encoding ornithine acetyltransferase from Neisseria gonorrhoeae." Journal of Bacteriology 174, no. 8 (1992): 2694–701. http://dx.doi.org/10.1128/jb.174.8.2694-2701.1992.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

26

Dou, Wenfang, Meijuan Xu, Dongmei Cai, Xiaomei Zhang, Zhiming Rao, and Zhenghong Xu. "Improvement of l-Arginine Production by Overexpression of a Bifunctional Ornithine Acetyltransferase in Corynebacterium crenatum." Applied Biochemistry and Biotechnology 165, no. 3-4 (July 23, 2011): 845–55. http://dx.doi.org/10.1007/s12010-011-9302-3.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

27

Fogel-Petrovic, Mirjana, Slavoljub Vujcic, John Miller, and Carl W. Porter. "Differential post-transcriptional control of ornithine decarboxylase and spermidine-spermine N 1 -acetyltransferase by polyamines." FEBS Letters 391, no. 1-2 (August 5, 1996): 89–94. http://dx.doi.org/10.1016/0014-5793(96)00710-7.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

28

Marc, Frédéric, Pierre Weigel, Christianne Legrain, Nicolas Glansdorff, and Vehary Sakanyan. "An Invariant Threonine Is Involved in Self-catalyzed Cleavage of the Precursor Protein for Ornithine Acetyltransferase." Journal of Biological Chemistry 276, no. 27 (April 24, 2001): 25404–10. http://dx.doi.org/10.1074/jbc.m100392200.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

29

Halmekytö, M., L. Alhonen, J. Wahlfors, R. Sinervirta, T. Eloranta, and J. Jänne. "Characterization of a transgenic mouse line over-expressing the human ornithine decarboxylase gene." Biochemical Journal 278, no. 3 (September 15, 1991): 895–98. http://dx.doi.org/10.1042/bj2780895.

Повний текст джерела

Анотація:

We have produced several transgenic mouse lines over-expressing the human ornithine decarboxylase (ODC) gene. We have now characterized one of the transgenic lines as regards the tissue accumulation of the polyamines and the activities of their metabolizing enzymes. Among the tissues analysed, the polyamine pattern was most strikingly changed in testis and brain of the transgenic animals. ODC activity was greatly enhanced in all tissues, except kidney, of the transgenic animals. The most dramatic increase, 80-fold, was found in brain of the transgenic mice. The activities of S-adenosylmethionine decarboxylase and spermidine and spermine syntheses were likewise significantly increased in testis of the transgenic animals. The activities of the enzymes involved in the back-conversion of the polyamines, namely spermidine/spermine acetyltransferase and polyamine oxidase, were similar in the transgenic and non-transgenic animals. As analysed by reverse transcriptase/polymerase chain reaction, all the six tissues of the transgenic animals expressed human-specific ODC mRNA. Determination of the half-life of testicular ODC revealed a stabilization of the enzyme in the transgenic males.

Стилі APA, Harvard, Vancouver, ISO та ін.

30

Mao, Y., J. A. Gurr, and N. J. Hickok. "Retinoic acid regulates ornithine decarboxylase gene expression at the transcriptional level." Biochemical Journal 295, no. 3 (November 1, 1993): 641–44. http://dx.doi.org/10.1042/bj2950641.

Повний текст джерела

Анотація:

Retinoic acid (RA) is important for normal mammalian development and growth. Ornithine decarboxylase (ODC) is the first and rate-limiting enzyme in the biosynthesis of the polyamines, and we have previously shown that ODC mRNA levels are suppressed by RA in human skin cells. Using HeLa cells, we now show that treatment with 0.5 microM RA for 24 h suppresses endogenous ODC mRNA levels and the expression of a transfected ODC/chloramphenicol acetyltransferase plasmid (Kpn-ODCCAT), containing sequences from -1450 to +810 of the human ODC gene. Co-transfection with either the alpha-RA receptor (alpha-RAR) or a chimeric alpha-RA/oestrogen receptor (alpha-RAER) followed by treatment with the cognate hormone suppresses expression of Kpn-ODCCAT and Not-ODCCAT, which contains sequences from -250 to +514. Liganded alpha-RAR suppresses the activity of Kpn-ODCCAT more markedly than does liganded alpha-RAER (98% and 80% suppression, respectively), whereas both receptors have very similar effects on Not-ODCCAT expression (73% and 67% suppression, respectively). The unliganded alpha-RAR suppresses Kpn-ODCCAT by 76%, whereas unliganded alpha-RAER has no significant effect. These data show that RA regulates ODC-gene expression at the transcriptional level, and that alpha-RAR, but not alpha-RAER, can confer full hormonal responsiveness. This suggests that the activating function present in the alpha-RAR ligand-binding domain is required for full transcriptional regulation.

Стилі APA, Harvard, Vancouver, ISO та ін.

31

SCORCIONI, Francesca, Arnaldo CORTI, Pierpaola DAVALLI, Serenella ASTANCOLLE, and Saverio BETTUZZI. "Manipulation of the expression of regulatory genes of polyamine metabolism results in specific alterations of the cell-cycle progression." Biochemical Journal 354, no. 1 (February 8, 2001): 217–23. http://dx.doi.org/10.1042/bj3540217.

Повний текст джерела

Анотація:

We have previously reported that cyclical phases of accumulation and depletion of polyamines occur during cell-cycle progression. Regulatory ornithine decarboxylase (ODC) catalyses the first step of polyamine biosynthesis. Ornithine decarboxylase antizyme (OAZ), induced by high polyamine levels, inhibits ODC activity and prevents extracellular polyamine uptake. Spermidine/spermine N1-acetyltransferase (SSAT) regulates the polyamine degradation/excretion pathway. Here we show that 24h transient transfection of immortalized human prostatic epithelial cells (PNT1A and PNT2) with antisense ODC RNA or OAZ cDNA, or both, while effectively causing marked decreases of ODC activity and polyamine (especially putrescine) concentrations, resulted in accumulation of cells in the S phase of the cell cycle. Transfection with SSAT cDNA led to more pronounced decreases in spermidine and spermine levels and resulted in accumulation of cells in the G2/M phases. Transfection with all three constructs together produced maximal depletion of all polyamines, accompanied by accumulation of PNT1A cells in the S phase and PNT2 cells in the G0/G1 and G2/M phases. Accumulation of PNT1A cells in the S phase progressively increased at 15, 18 and 24h of transfection with antisense ODC and/or OAZ cDNA. At 24h, the DNA content was always reduced, as a possible outcome of altered chromosome condensation. A direct link between polyamine metabolism, cell proliferation and chromatin structure is thus proposed.

Стилі APA, Harvard, Vancouver, ISO та ін.

32

Hirvonen, A., T. Eloranta, T. Hyvönen, L. Alhonen, and J. Jänne. "Characterization of difluoromethylornithine-resistant mouse and human tumour cell lines." Biochemical Journal 258, no. 3 (March 15, 1989): 709–13. http://dx.doi.org/10.1042/bj2580709.

Повний текст джерела

Анотація:

Four mouse and two human tumour cell lines resistant to alpha-difluoromethylornithine (DFMO), an irreversible inhibitor of ornithine decarboxylase (ODC), were analysed for the activities of polyamine-biosynthetic and -biodegradative enzymes as well as for cellular polyamine contents. In all but one of these cell lines the resistance to DFMO was based on an overproduction of ODC. In a human myeloma cell line the resistance was based on a greatly enhanced arginase activity. Except for one L1210 variant cell line, all the resistant cell lines contained elevated S-adenosylmethionine decarboxylase activity. Similarly, all the resistant mouse, but not human, cell lines displayed enhanced spermidine and spermine synthase activities. Arginase activity was detected only in human cell lines. In both DFMO-resistant cell lines the activity of arginase was strikingly elevated. Of the biodegradative enzymes, polyamine oxidase activity was readily detectable in all mouse cells, but no measurable activity was found in the human cells. Spermidine/spermine N1-acetyltransferase activity was elevated in three out of four resistant mouse cell lines. Even though the concentration of spermidine was usually lower in the overproducer cells, this was compensated by an increased content of spermine. The two resistant human myeloma cells contained intracellular ornithine concentrations that were from more than 5 to more than 20 times higher than those in the parental cells.

Стилі APA, Harvard, Vancouver, ISO та ін.

33

HUGHES, Alun, Nicholas I. SMITH, and Heather M. WALLACE. "Polyamines reverse non-steroidal anti-inflammatory drug-induced toxicity in human colorectal cancer cells." Biochemical Journal 374, no. 2 (September 1, 2003): 481–88. http://dx.doi.org/10.1042/bj20030280.

Повний текст джерела

Анотація:

Naproxen, sulindac and salicylate, three NSAIDs (non-steroidal anti-inflammatory drugs), were cytotoxic to human colorectal cancer cells in culture. Toxicity was accompanied by significant depletion of intracellular polyamine content. Inhibition of ornithine decarboxylase (the first enzyme of the polyamine biosynthetic pathway), induction of polyamine oxidase and spermidine/spermine N1-acetyltransferase (the enzymes responsible for polyamine catabolism) and induction of polyamine export all contributed to the decreased intracellular polyamine content. Morphological examination of the cells showed typical signs of apoptosis, and this was confirmed by DNA fragmentation and measurement of caspase-3-like activity. Re-addition of spermidine to the cells partially prevented apoptosis and recovered the cell number. Thus polyamines appear to be an integral part of the signalling pathway mediating NSAID toxicity in human colorectal cancer cells, and may therefore also be important in cancer chemoprevention in humans.

Стилі APA, Harvard, Vancouver, ISO та ін.

34

Cheng, Hua, and Nick V. Grishin. "DOM-fold: A structure with crossing loops found in DmpA, ornithine acetyltransferase, and molybdenum cofactor-binding domain." Protein Science 14, no. 7 (July 2005): 1902–10. http://dx.doi.org/10.1110/ps.051364905.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

35

NISHIKAWA, Yuji, Siddhartha KAR, Laurie WIEST, Anthony E. PEGG та Brian I. CARR. "Inhibition of spermidine synthase gene expression by transforming growth factor-β1 in hepatoma cells". Biochemical Journal 321, № 2 (15 січня 1997): 537–43. http://dx.doi.org/10.1042/bj3210537.

Повний текст джерела

Анотація:

We screened genes responsive to transforming growth factor-α (TGF-α1) protein in a human hepatoma cell line (Hep3B) using a PCR-mediated differential display technique, in order to investigate the mechanisms involved in TGF-α-induced growth suppression. We found a gene that was down-regulated by TGF-α1 to be completely identical in an approx. 620 bp segment to the gene for the enzyme spermidine synthase, which mediates the conversion of putrescine into spermidine. Both spermidine synthase mRNA expression and its enzyme activity were decreased after TGF-α1 treatment of Hep3B cells. The inhibition of spermidine synthase gene expression by TGF-α1 protein was also observed in other hepatoma cell lines. The expression of genes for other biosynthetic enzymes in polyamine metabolism (ornithine decarboxylase and S-adenosylmethionine decarboxylase) was also inhibited to the same extent as for spermidine synthase, while the gene expression of spermidine/spermine N1-acetyltransferase, a catabolic enzyme, was relatively resistant to TGF-α1. Spermine levels in Hep3B cells were decreased by TGF-α1 treatment, although the levels of spermidine and putrescine were unchanged, probably due to compensation by remaining spermidine/spermine N1-acetyltransferase activity. Exogenously added spermidine or spermine, but not putrescine, partially antagonized the growth-inhibitory effects of TGF-α1 on Hep3B cells. Our data suggest that down-regulation of gene expression of the enzymes involved in polyamine metabolism, including spermidine synthase, may be associated with the mechanism of TGF-α-induced growth suppression.

Стилі APA, Harvard, Vancouver, ISO та ін.

36

Crabeel, Marjolaine, Agnes Abadjieva, Pierre Hilven, Joke Desimpelaere, and Oriane Soetens. "Characterization of the Saccharomyces cerevisiae ARG7 Gene Encoding Ornithine Acetyltransferase, An Enzyme also Endowed with Acetylglutamate Synthase Activity." European Journal of Biochemistry 250, no. 2 (December 1997): 232–41. http://dx.doi.org/10.1111/j.1432-1033.1997.0232a.x.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

37

FRASER, Alison V., Patrick M. WOSTER, and Heather M. WALLACE. "Induction of apoptosis in human leukaemic cells by IPENSpm, a novel polyamine analogue and anti-metabolite." Biochemical Journal 367, no. 1 (October 1, 2002): 307–12. http://dx.doi.org/10.1042/bj20020156.

Повний текст джерела

Анотація:

Human promyelogenous leukaemic cells (HL-60) were treated with novel spermine analogue, (S)-N1-(2-methyl-1-butyl)-N11-ethyl-4,8-diazaundecane (IPENSpm), and the effects on growth and intracellular polyamine metabolism were measured. IPENSpm was cytotoxic to these cells at concentrations greater than 2.5μM. It induced apoptosis in a caspase-dependent manner and its toxicity profile was comparable with etoposide, a well-known anti-tumour agent and inducer of apoptosis. IPENSpm decreased intracellular polyamine content as a result of changes in ornithine decarboxylase activity and increases in spermidine/spermine N1-acetyltransferase and polyamine export. Analysis showed spermine and spermidine as the major intracellular polyamines, while putrescine and acetyl-polyamines were the main export compounds. IPENSpm used the polyamine transporter system for uptake and its accumulation in cells was prevented by polyamine transport inhibitors. IPENSpm can be classified as a polyamine anti-metabolite and it may be a promising new lead compound in terms of treatment of some human cancers.

Стилі APA, Harvard, Vancouver, ISO та ін.

38

Shinki, T., T. Kadofuku, T. Sato, and T. Suda. "Spermidine N1-acetyltransferase has a larger role than ornithine decarboxylase in 1 alpha,25-dihydroxyvitamin D3-induced putrescine synthesis." Journal of Biological Chemistry 261, no. 25 (September 1986): 11712–16. http://dx.doi.org/10.1016/s0021-9258(18)67302-8.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

39

Hong, Kyongsu. "Characterization of the arginine deiminase ofStreptococcus equisubsp.zooepidemicus." Canadian Journal of Microbiology 52, no. 9 (September 1, 2006): 868–76. http://dx.doi.org/10.1139/w06-041.

Повний текст джерела

Анотація:

Streptococcus equi subsp. zooepidemicus is an important cause of infectious diseases in horses and rarely humans. Little is known about the virulence factors or protective antigens of S. equi subsp. zooepidemicus. In the present study, I designed original primers based on an alignment of the gene sagp(arcA) from Streptococcus pyogenes encoding streptococcal acid glycoprotein – arginine deiminase (SAGP/AD) to amplify the S. equi subsp. zooepidemicus counterpart sequence by polymerase chain reaction, and I analyzed the sagp(arcA) gene of the organism. Using chromosomal walking steps, I identified a contiguous eight-gene locus involved in SAGP/AD production. Their open reading frames were found to share significant homologies and to correspond closely in molecular mass to previously sequenced arc genes of S. pyogenes, thus they were designated ahrC.2 (arginine repressor), arcR (CRP/FNR transcription regulator), sagp(arcA) (streptococcal acid glycoprotein – arginine deiminase), putative acetyltransferase gene, arcB (ornithine carbamyl transferase), arcD (arginine–ornithine antiporter), arcT (Xaa-His peptidase), and arcC (carbamate kinase). The SAGP homologue of S. equi subsp. zooepidemicus (SzSAGP), encoded by arcA gene of the bacteria (arcA(SZ)), was successfully expressed in Escherichia coli and purified to homogeneity. When in vitro growth inhibitory activity of the recombinant SzSAGP was tested against MOLT-3 cells, it inhibited the growth of the cells during the 3 days of culture in a dose-dependent manner, accompanied by the induction of apoptotic cell death. The recombinant protein also possessed AD activity. By immunoblot analysis using both anti-SzSAGP-SfbI(H8) and anti-SfbI(H8) sera, I was able to demonstrate that the SzSAGP protein is expressed on the streptococcal surface.Key words: SAGP, arginine deiminase, Streptococcus equi subsp. zooepidemicus.

Стилі APA, Harvard, Vancouver, ISO та ін.

40

Andersen, Synne M., Elisabeth Holen, Anders Aksnes, Ivar Rønnestad, Jens-Erik Zerrahn, and Marit Espe. "Dietary arginine affects energy metabolism through polyamine turnover in juvenile Atlantic salmon (Salmo salar)." British Journal of Nutrition 110, no. 11 (May 9, 2013): 1968–77. http://dx.doi.org/10.1017/s0007114513001402.

Повний текст джерела

Анотація:

In the present study, quadruplicate groups of juvenile Atlantic salmon (Salmo salar) were fed plant protein-based diets with increasing arginine inclusions (range 28·8–37·4 g/kg DM) to investigate whether arginine supplementation affects growth and lipid accumulation through an elevated polyamine turnover. Dietary lysine was held at a constant concentration, just below the requirement. All other amino acids were balanced and equal in the diets. Arginine supplementation increased protein and fat accretion, without affecting the hepatosomatic or visceralsomatic indices. Dietary arginine correlated with putrescine in the liver (R 0·78, P= 0·01) and with ornithine in the muscle, liver and plasma (P= 0·0002, 0·003 and 0·0002, respectively). The mRNA of ornithine decarboxylase, the enzyme producing putrescine, was up-regulated in the white adipose tissue of fish fed the high-arginine inclusion compared with those fed the low-arginine diet. Concomitantly, spermidine/spermine-(N1)-acetyltransferase, the rate-limiting enzyme for polyamine turnover that consumes acetyl-CoA, showed an increased activity in the liver of fish fed the arginine-supplemented diets. In addition, lower acetyl-CoA concentrations were observed in the liver of fish fed the high-arginine diet, while ATP, which is used in the process of synthesising spermidine and spermine, did not show a similar trend. Gene expression of the rate-limiting enzyme for β-oxidation of long-chain fatty acids, carnitine palmitoyl transferase-1, was up-regulated in the liver of fish fed the high-arginine diet. Taken together, the data support that increased dietary arginine activates polyamine turnover and β-oxidation in the liver of juvenile Atlantic salmon and may act to improve the metabolic status of the fish.

Стилі APA, Harvard, Vancouver, ISO та ін.

41

SUPPOLA, Suvikki, Sami HEIKKINEN, Jyrki J. PARKKINEN, Mikko UUSI-OUKARI, Veli-Pekka KORHONEN, Tuomo KEINÄNEN, Leena ALHONEN, and Juhani JÄNNE. "Concurrent overexpression of ornithine decarboxylase and spermidine/spermine N1-acetyltransferase further accelerates the catabolism of hepatic polyamines in transgenic mice." Biochemical Journal 358, no. 2 (September 1, 2001): 343. http://dx.doi.org/10.1042/0264-6021:3580343.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

42

SUPPOLA, Suvikki, Sami HEIKKINEN, Jyrki J. PARKKINEN, Mikko UUSI-OUKARI, Veli-Pekka KORHONEN, Tuomo KEINÄNEN, Leena ALHONEN, and Juhani JÄNNE. "Concurrent overexpression of ornithine decarboxylase and spermidine/spermine N1-acetyltransferase further accelerates the catabolism of hepatic polyamines in transgenic mice." Biochemical Journal 358, no. 2 (August 24, 2001): 343–48. http://dx.doi.org/10.1042/bj3580343.

Повний текст джерела

Анотація:

We have generated a hybrid transgenic mouse line overexpressing both ornithine decarboxylase (ODC) and spermidine/spermine N1-acetyltransferase (SSAT) under the control of the mouse metallothionein (MT) I promoter. In comparison with singly transgenic animals overexpressing SSAT, the doubly transgenic mice unexpectedly displayed much more striking signs of activated polyamine catabolism, as exemplified by a massive putrescine accumulation and an extreme reduction of hepatic spermidine and spermine pools. Interestingly, the profound depletion of the higher polyamines in the hybrid animals occurred in the presence of strikingly high ODC activity and tremendous putrescine accumulation. Polyamine catabolism in the doubly transgenic mice could be enhanced further by administration of zinc or the polyamine analogue N1,N11-diethylnorspermine. In tracer experiments with [14C]spermidine we found that, in comparison with syngenic animals, both MT-ODC and MT-SSAT mice possessed an enhanced efflux mechanism for hepatic spermidine. In the MT-ODC animals this mechanism apparently operated in the absence of measurable SSAT activity. In the hybrid animals, spermidine efflux was stimulated further in comparison with the singly transgenic animals. In spite of a dramatic accumulation of putrescine and a profound reduction of the spermidine and spermine pools, only marginal changes were seen in the level of ODC antizyme. Even though the hybrid animals showed no liver or other organ-specific overt toxicity, except an early and permanent loss of hair, their life span was greatly reduced. These results can be understood from the perspective that catabolism is the overriding regulatory mechanism in the metabolism of the polyamines and that, even under conditions of severe depletion of spermidine and spermine, extremely high tissue pools of putrescine are not driven further to replenish the pools of the higher polyamines.

Стилі APA, Harvard, Vancouver, ISO та ін.

43

Fang, Yan, Jeffrey A. Coulter, Junyan Wu, Lijun Liu, Xuecai Li, Yun Dong, Li Ma, et al. "Identification of differentially expressed genes involved in amino acid and lipid accumulation of winter turnip rape (Brassica rapa L.) in response to cold stress." PLOS ONE 16, no. 2 (February 8, 2021): e0245494. http://dx.doi.org/10.1371/journal.pone.0245494.

Повний текст джерела

Анотація:

Winter turnip rape (Brassica rapa L.) is an important overwintering oil crop that is widely planted in northwestern China. It considered to be a good genetic resource for cold-tolerant research because its roots can survive harsh winter conditions. Here, we performed comparative transcriptomics analysis of the roots of two winter turnip rape varieties, Longyou7 (L7, strong cold tolerance) and Tianyou2 (T2, low cold tolerance), under normal condition (CK) and cold stress (CT) condition. A total of 8,366 differentially expressed genes (DEGs) were detected between the two L7 root groups (L7CK_VS_L7CT), and 8,106 DEGs were detected for T2CK_VS_T2CT. Among the DEGs, two ω-3 fatty acid desaturase (FAD3), two delta-9 acyl-lipid desaturase 2 (ADS2), one diacylglycerol kinase (DGK), and one 3-ketoacyl-CoA synthase 2 (KCS2) were differentially expressed in the two varieties and identified to be related to fatty acid synthesis. Four glutamine synthetase cytosolic isozymes (GLN), serine acetyltransferase 1 (SAT1), and serine acetyltransferase 3 (SAT3) were down-regulated under cold stress, while S-adenosylmethionine decarboxylase proenzyme 1 (AMD1) had an up-regulation tendency in response to cold stress in the two samples. Moreover, the delta-1-pyrroline-5-carboxylate synthase (P5CS), δ-ornithine aminotransferase (δ-OAT), alanine-glyoxylate transaminase (AGXT), branched-chain-amino-acid transaminase (ilvE), alpha-aminoadipic semialdehyde synthase (AASS), Tyrosine aminotransferase (TAT) and arginine decarboxylase related to amino acid metabolism were identified in two cultivars variously expressed under cold stress. The above DEGs related to amino acid metabolism were suspected to the reason for amino acids content change. The RNA-seq data were validated by real-time quantitative RT-PCR of 19 randomly selected genes. The findings of our study provide the gene expression profile between two varieties of winter turnip rape, which lay the foundation for a deeper understanding of the highly complex regulatory mechanisms in plants during cold treatment.

Стилі APA, Harvard, Vancouver, ISO та ін.

44

Otani, Kenjiro, Yoshihisa Yano, Tadayoshi Hasuma, Tetsuo Arakawa, Kenzo Kobayashi, Isao Matsui-Yuasa, and Shuzo Otani. "Polyamine metabolism of rat gastric mucosa after oral administration of hypertonic sodium chloride solution." American Journal of Physiology-Gastrointestinal and Liver Physiology 274, no. 2 (February 1, 1998): G299—G305. http://dx.doi.org/10.1152/ajpgi.1998.274.2.g299.

Повний текст джерела

Анотація:

Oral administration of 1 ml of 3.42 M NaCl solution to rats induced spermidine/spermine N 1-acetyltransferase (SSAT) activity in gastric mucosa as well as ornithine decarboxylase (ODC) activity. SSAT activity increased and peaked at 5 h and again at 7 h, whereas ODC activity peaked at 6 h. SSAT mRNA also increased after 3.42 M NaCl administration to an extent similar to the increase in SSAT activity at 5 h. Intracellular putrescine level and DNA synthesis were increased by NaCl administration. A polyamine oxidase inhibitor, N, N′-bis(2,3-butadienyl)-1,4-butanediamine (MDL-72527), but not an ODC inhibitor, α-difluoromethylornithine (DFMO), inhibited the increases in putrescine level and DNA synthesis at 5 h. The inhibition of DNA synthesis by MDL-72527 was reversed by putrescine administration. In contrast, both MDL-72527 and DFMO inhibited the increase in putrescine level and DNA synthesis at 16.5 h. These findings suggest that putrescine produced from preexistent spermidine by SSAT is responsible for the initial DNA synthesis after mucosal injury induced by NaCl and that both SSAT and ODC are involved in formation of putrescine, which is required for subsequent DNA synthesis.

Стилі APA, Harvard, Vancouver, ISO та ін.

45

Babbar, N., and E. W. Gerner. "Polyamines as modifiers of genetic risk factors in human intestinal cancers." Biochemical Society Transactions 31, no. 2 (April 1, 2003): 388–92. http://dx.doi.org/10.1042/bst0310388.

Повний текст джерела

Анотація:

Polyamines are downstream mediators of genetic risk factors in human intestinal cancers. The adenomatous polyposis coli (APC) tumour-suppressor gene, which is mutated in essentially all human colon cancers, regulates the expression of several e-box transcription factors. These factors, in turn, regulate the transcription of ornithine decarboxylase (ODC), the first enzyme in polyamine synthesis. The Kirsten ras (K-ras) oncogene regulates the expression of several genes, including suppressing the expression of peroxisomal proliferator-activated receptor γ (PPARγ). This PPAR, in turn, activates the expression of the spermidine/spermine-N1-acetyltransferase (SSAT), the first enzyme in polyamine catabolism. The non-steroidal anti-inflammatory drug (NSAID) sulindac induces the transcription of SSAT via activation of PPARγ. Inactivation of the APC tumour-suppressor gene, and the activation of K-ras, have a combined effect on increasing tissue polyamine contents due to increased synthesis and decreased catabolism of the polyamines. Pharmacological strategies for suppressing ODC (e.g. the enzyme-activated inhibitor α-difluoromethylornithine) and activating SSAT (e.g. NSAIDs) are potent inhibitors of intestinal carcinogenesis in rodent models. Clinical trials combining these classes of agent in humans with risk factors for colon cancer are in progress.

Стилі APA, Harvard, Vancouver, ISO та ін.

46

Arrebola, Eva, Francisco M. Cazorla, Diego Romero, Alejandro Pérez-García, and Antonio de Vicente. "A Nonribosomal Peptide Synthetase Gene (mgoA) of Pseudomonas syringae pv. syringae Is Involved in Mangotoxin Biosynthesis and Is Required for Full Virulence." Molecular Plant-Microbe Interactions® 20, no. 5 (May 2007): 500–509. http://dx.doi.org/10.1094/mpmi-20-5-0500.

Повний текст джерела

Анотація:

Pseudomonas syringae pv. syringae, which causes the bacterial apical necrosis of mango, produces the antimetabolite mangotoxin. We report here the cloning, sequencing, and identity analysis of a chromosomal region of 11.1 kb from strain P. syringae pv. syringae UMAF0158, which is involved in mangotoxin biosynthesis. This chromosomal region contains six complete open reading frames (ORFs), including a large gene (ORF5) with a modular architecture characteristic of nonribosomal peptide synthetases (NRPS) named mgoA. A Tn 5 mutant disrupted in mgoA was defective in mangotoxin production, revealing the involvement of the putative NRPS gene in the biosynthesis of mangotoxin. This derivative strain impaired in mangotoxin production also showed a reduction in virulence as measured by necrotic symptoms on tomato leaflets. Mangotoxin production and virulence were restored fully in the NRPS mutant by complementation with plasmid pCG2-6, which contains an 11,103-bp chromosomal region cloned from the wildtype strain P. syringae pv. syringae UMAF0158 that includes the putative NPRS gene (mgoA). The results demonstrate that mgoA has a role in the virulence of P. syringae pv. syringae. The involvement of an NRPS in the production of an antimetabolite toxin from P. syringae inhibiting ornithine acetyltransferase activity is proposed.

Стилі APA, Harvard, Vancouver, ISO та ін.

47

Chai, Nannan, Hao Zhang, Lingxu Li, Xue Yu, Yan Liu, Yan Lin, Lina Wang, Jiamin Yan, Sazonova Elena Nikolaevna, and Yajun Zhao. "Spermidine Prevents Heart Injury in Neonatal Rats Exposed to Intrauterine Hypoxia by Inhibiting Oxidative Stress and Mitochondrial Fragmentation." Oxidative Medicine and Cellular Longevity 2019 (May 14, 2019): 1–14. http://dx.doi.org/10.1155/2019/5406468.

Повний текст джерела

Анотація:

Intrauterine hypoxia (IUH) is a common intrauterine dysplasia that can cause programming of the offspring cardiovascular system. In this study, we hypothesized that placental treatment with spermidine (SPD) can prevent heart injury in neonatal offspring exposed to IUH. Pregnant rats were exposed to 21% O2 or 10% O2 (hypoxia) for 7 days prior to term or were exposed to hypoxia and intraperitoneally administered SPD or SPD+difluromethylornithine (DFMO) on gestational days 15-21. Seven-day-old offspring were then sacrificed to assess several parameters. Our results demonstrated that IUH led to decreased myocardial ornithine decarboxylase (ODC) and increased spermidine/spermine N1-acetyltransferase (SSAT) expression in the offspring. IUH also resulted in decreased offspring body weight, heart weight, cardiomyocyte proliferation, and antioxidant capacity and increased cardiomyocyte apoptosis and fibrosis. Furthermore, IUH caused mitochondrial structure abnormality, dysfunction, and decreased biogenesis and led to a fission/fusion imbalance in offspring hearts. In vitro, hypoxia induced mitochondrial ROS accumulation, decreased membrane potential, and increased fragmentation. Notably, all hypoxia-induced changes analyzed in this study were prevented by SPD. Thus, in utero SPD treatment is a potential strategy for preventing IUH-induced neonatal cardiac injury.

Стилі APA, Harvard, Vancouver, ISO та ін.

48

Wang, Weiwei, Hao Zhang, Guo Xue, Li Zhang, Weihua Zhang, Lina Wang, Fanghao Lu, et al. "Exercise Training Preserves Ischemic Preconditioning in Aged Rat Hearts by Restoring the Myocardial Polyamine Pool." Oxidative Medicine and Cellular Longevity 2014 (2014): 1–14. http://dx.doi.org/10.1155/2014/457429.

Повний текст джерела

Анотація:

Background. Ischemic preconditioning (IPC) strongly protects against myocardial ischemia reperfusion (IR) injury. However, IPC protection is ineffective in aged hearts. Exercise training reduces the incidence of age-related cardiovascular disease and upregulates the ornithine decarboxylase (ODC)/polyamine pathway. The aim of this study was to investigate whether exercise can reestablish IPC protection in aged hearts and whether IPC protection is linked to restoration of the cardiac polyamine pool.Methods. Rats aging 3 or 18 months perform treadmill exercises with or without gradient respectively for 6 weeks. Isolated hearts and isolated cardiomyocytes were exposed to an IR and IPC protocol.Results. IPC induced an increase in myocardial polyamines by regulating ODC and spermidine/spermine acetyltransferase (SSAT) in young rat hearts, but IPC did not affect polyamine metabolism in aged hearts. Exercise training inhibited the loss of preconditioning protection and restored the polyamine pool by activating ODC and inhibiting SSAT in aged hearts. An ODC inhibitor,α-difluoromethylornithine, abolished the recovery of preconditioning protection mediated by exercise. Moreover, polyamines improved age-associated mitochondrial dysfunctionin vitro.Conclusion. Exercise appears to restore preconditioning protection in aged rat hearts, possibly due to an increase in intracellular polyamines and an improvement in mitochondrial function in response to a preconditioning stimulus.

Стилі APA, Harvard, Vancouver, ISO та ін.

49

Grzelakowska-Sztabert, B., M. Dudkowska, and M. Manteuffel-Cymborowska. "Nuclear and membrane receptor-mediated signalling pathways modulate polyamine biosynthesis and interconversion." Biochemical Society Transactions 35, no. 2 (March 20, 2007): 386–90. http://dx.doi.org/10.1042/bst0350386.

Повний текст джерела

Анотація:

Polyamines play an important role in cell growth and differentiation, while their overproduction has potentially oncogenic consequences. Polyamine homoeostasis, a critical determinant of cell fate, is precisely tuned at the level of biosynthesis, degradation and transport. The enzymes ODC (ornithine decarboxylase), AdoMetDC (S-adenosylmethionine decarboxylase) and SSAT (spermidine/spermine N1-acetyltransferase) are critical for polyamine pool maintenance. Our experiments were designed to examine the expression of these enzymes in testosterone-induced hypertrophic and antifolate-induced hyperplastic mouse kidney, characterized by activation of AR (androgen receptor) and HGF (hepatocyte growth factor) membrane receptor c-Met respectively. The expression of these key enzymes was up-regulated by antifolate CB 3717 injury-evoked activation of HGF/c-Met signalling. In contrast, activation of the testosterone/AR pathway remarkably induced a selective increase in ODC expression without affecting other enzymes. Studies in catecholamine-depleted kidneys point to a synergistic interaction between the signalling pathways activated via cell membrane catecholamine receptors and AR, as well as c-Met. We found that this cross-talk modulated the expression of ODC and AdoMetDC, enzymes limiting polyamine biosynthesis, but not SSAT. This is in contrast with the antagonistic cross-talk between AR- and c-Met-mediated signalling which negatively regulated the expression of ODC, but affected neither AdoMetDC nor SSAT.

Стилі APA, Harvard, Vancouver, ISO та ін.

50

Harari, P. M., M. E. Tome, D. J. M. Fuller, S. W. Carper, and E. W. Gerner. "Effects of diethyldithiocarbamate and endogenous polyamine content on cellular responses to hydrogen peroxide cytotoxicity." Biochemical Journal 260, no. 2 (June 1, 1989): 487–90. http://dx.doi.org/10.1042/bj2600487.

Повний текст джерела

Анотація:

In exponential-phase Chinese-hamster cells, 0.1 mM-diethyldithiocarbamate (DDC) afforded greater than 1 log survival protection to cultures treated before and during exposure to 1 mM-H2O2. Both DDC and H2O2 treatment stimulated the activity of ornithine decarboxylase (ODC), the first enzyme in polyamine synthesis, within 4 h of exposure. DDC, and to a lesser degree H2O2, also stimulated the activity of spermidine N1-acetyltransferase (SAT), the rate-limiting enzyme in polyamine catabolism. The increase in SAT activity, after exposure to DDC or another stress (heat shock), was inhibited in cells depleted of putrescine and spermidine by alpha-difluoromethylornithine (DFMO), the enzyme-activated suicide inhibitor of ODC. Pretreatment with DFMO or heat shock also induced resistance to H2O2 cytotoxicity. Since SAT activity is low in resting cells, yet stimulation of enzyme activity depends on endogenous spermidine pools, these results suggest that the expression of SAT activity occurs by a mechanism involving a stress-dependent displacement of spermidine into a new intracellular compartment. The stimulation of ODC and SAT activities does not appear to be a necessary component of the mechanism by which DDC protects cells from H2O2 cytotoxicity, although spermidine displacement may be a common facet of the cellular response to stress.

Стилі APA, Harvard, Vancouver, ISO та ін.

Статті в журналах з теми "Ornithine Acetyltransferase"

Оформте джерело за APA, MLA, Chicago, Harvard та іншими стилями