Littérature scientifique sur le sujet « Pyrroline-5-carboxylate complex »
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Articles de revues sur le sujet "Pyrroline-5-carboxylate complex"
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Terao, Yukiyasu, Shigeru Nakamori et Hiroshi Takagi. « Gene Dosage Effect of l-Proline Biosynthetic Enzymes on l-Proline Accumulation and Freeze Tolerance in Saccharomyces cerevisiae ». Applied and Environmental Microbiology 69, no 11 (novembre 2003) : 6527–32. http://dx.doi.org/10.1128/aem.69.11.6527-6532.2003.
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ABSTRACT We have previously reported that l-proline has cryoprotective activity in Saccharomyces cerevisiae. A freeze-tolerant mutant with l-proline accumulation was recently shown to carry an allele of the PRO1 gene encoding γ-glutamyl kinase, which resulted in a single amino acid substitution (Asp154Asn). Interestingly, this mutation enhanced the activities of γ-glutamyl kinase and γ-glutamyl phosphate reductase, both of which catalyze the first two steps of l-proline synthesis and which together may form a complex in vivo. Here, we found that the Asp154Asn mutant γ-glutamyl kinase was more thermostable than the wild-type enzyme, which suggests that this mutation elevated the apparent activities of two enzymes through a stabilization of the complex. We next examined the gene dosage effect of three l-proline biosynthetic enzymes, including Δ1-pyrroline-5-carboxylate reductase, which converts Δ1-pyrroline-5-carboxylate into l-proline, on l-proline accumulation and freeze tolerance in a non-l-proline-utilizing strain. Overexpression of the wild-type enzymes has no influence on l-proline accumulation, which suggests that the complex is very unstable in nature. However, co-overexpression of the mutant γ-glutamyl kinase and the wild-type γ-glutamyl phosphate reductase was effective for l-proline accumulation, probably due to a stabilization of the complex. These results indicate that both enzymes, not Δ1-pyrroline-5-carboxylate reductase, are rate-limiting enzymes in yeast cells. A high tolerance for freezing clearly correlated with higher levels of l-proline in yeast cells. Our findings also suggest that, in addition to its cryoprotective activity, intracellular l-proline could protect yeast cells from damage by oxidative stress. The approach described here provides a valuable method for breeding novel yeast strains that are tolerant of both freezing and oxidative stresses.
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Ion, Bogdan F., Mohamed M. Aboelnga et James W. Gauld. « Insights from molecular dynamics on substrate binding and effects of active site mutations in Δ1-pyrroline-5-carboxylate dehydrogenase ». Canadian Journal of Chemistry 94, no 12 (décembre 2016) : 1151–62. http://dx.doi.org/10.1139/cjc-2016-0286.
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The NAD+-dependent enzyme, Δ1-pyrroline-5-carboxylate dehydrogenase (P5CDH), has an important role in proline and hydroxyproline catabolism for humans. Specifically, this aldehyde dehydrogenase is responsible for the oxidation of both l-glutamate-γ-semialdehyde (GSA) and 4-erythro-hydroxy-l-glutamate-γ-semialdehyde (4-OH-GSA) to their respective l-glutamate product forms. We have performed a detailed molecular dynamics (MD) study of both the reactant and product complex structures of P5CDH to gain insights into ligand binding (i.e., GSA, 4-OH-GSA, NAD+, GLU) in the active site. Moreover, our investigations were further extended to examine the structural impact of S352L, S352A, and E314A mutations on the deficiency in the P5CDH enzymatic activity. Our in silico mutation analysis indicated that the conserved Glu447 has significantly shifted in both the S352L and E314A mutants, causing NAD+ to be displaced from its predictive orientation in the binding site and hence forming a catalytically inactive enzyme. However in the case of S352A, the catalytic site including the oxyanion hole and Cys348 remain virtually unchanged, and the coenzyme maintains its binding position.
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Kretz, Rita, Bita Bozorgmehr, Mohamad Hasan Kariminejad, Marianne Rohrbach, Ingrid Hausser, Alessandra Baumer, Matthias Baumgartner, Cecilia Giunta, Ariana Kariminejad et Johannes Häberle. « Defect in proline synthesis : pyrroline-5-carboxylate reductase 1 deficiency leads to a complex clinical phenotype with collagen and elastin abnormalities ». Journal of Inherited Metabolic Disease 34, no 3 (13 avril 2011) : 731–39. http://dx.doi.org/10.1007/s10545-011-9319-3.
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Pallag, Gergely, Sara Nazarian, Dora Ravasz, David Bui, Timea Komlódi, Carolina Doerrier, Erich Gnaiger, Thomas N. Seyfried et Christos Chinopoulos. « Proline Oxidation Supports Mitochondrial ATP Production When Complex I Is Inhibited ». International Journal of Molecular Sciences 23, no 9 (4 mai 2022) : 5111. http://dx.doi.org/10.3390/ijms23095111.
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The oxidation of proline to pyrroline-5-carboxylate (P5C) leads to the transfer of electrons to ubiquinone in mitochondria that express proline dehydrogenase (ProDH). This electron transfer supports Complexes CIII and CIV, thus generating the protonmotive force. Further catabolism of P5C forms glutamate, which fuels the citric acid cycle that yields the reducing equivalents that sustain oxidative phosphorylation. However, P5C and glutamate catabolism depend on CI activity due to NAD+ requirements. NextGen-O2k (Oroboros Instruments) was used to measure proline oxidation in isolated mitochondria of various mouse tissues. Simultaneous measurements of oxygen consumption, membrane potential, NADH, and the ubiquinone redox state were correlated to ProDH activity and F1FO-ATPase directionality. Proline catabolism generated a sufficiently high membrane potential that was able to maintain the F1FO-ATPase operation in the forward mode. This was observed in CI-inhibited mouse liver and kidney mitochondria that exhibited high levels of proline oxidation and ProDH activity. This action was not observed under anoxia or when either CIII or CIV were inhibited. The duroquinone fueling of CIII and CIV partially reproduced the effects of proline. Excess glutamate, however, could not reproduce the proline effect, suggesting that processes upstream of the glutamate conversion from proline were involved. The ProDH inhibitors tetrahydro-2-furoic acid and, to a lesser extent, S-5-oxo-2-tetrahydrofurancarboxylic acid abolished all proline effects. The data show that ProDH-directed proline catabolism could generate sufficient CIII and CIV proton pumping, thus supporting ATP production by the F1FO-ATPase even under CI inhibition.
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Silao, Fitz Gerald S., Tong Jiang, Biborka Bereczky-Veress, Andreas Kühbacher, Kicki Ryman, Nathalie Uwamohoro, Sabrina Jenull et al. « Proline catabolism is a key factor facilitating Candida albicans pathogenicity ». PLOS Pathogens 19, no 11 (2 novembre 2023) : e1011677. http://dx.doi.org/10.1371/journal.ppat.1011677.
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Candida albicans, the primary etiology of human mycoses, is well-adapted to catabolize proline to obtain energy to initiate morphological switching (yeast to hyphal) and for growth. We report that put1-/- and put2-/- strains, carrying defective Proline UTilization genes, display remarkable proline sensitivity with put2-/- mutants being hypersensitive due to the accumulation of the toxic intermediate pyrroline-5-carboxylate (P5C), which inhibits mitochondrial respiration. The put1-/- and put2-/- mutations attenuate virulence in Drosophila and murine candidemia models and decrease survival in human neutrophils and whole blood. Using intravital 2-photon microscopy and label-free non-linear imaging, we visualized the initial stages of C. albicans cells infecting a kidney in real-time, directly deep in the tissue of a living mouse, and observed morphological switching of wildtype but not of put2-/- cells. Multiple members of the Candida species complex, including C. auris, are capable of using proline as a sole energy source. Our results indicate that a tailored proline metabolic network tuned to the mammalian host environment is a key feature of opportunistic fungal pathogens.
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Lagautriere, Thomas, Ghader Bashiri et Edward N. Baker. « Use of a “silver bullet” to resolve crystal lattice dislocation disorder : A cobalamin complex of Δ1-pyrroline-5-carboxylate dehydrogenase from Mycobacterium tuberculosis ». Journal of Structural Biology 189, no 2 (février 2015) : 153–57. http://dx.doi.org/10.1016/j.jsb.2014.12.007.
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Sun, Chenglong, Tiegang Li, Xiaowei Song, Luojiao Huang, Qingce Zang, Jing Xu, Nan Bi et al. « Spatially resolved metabolomics to discover tumor-associated metabolic alterations ». Proceedings of the National Academy of Sciences 116, no 1 (17 décembre 2018) : 52–57. http://dx.doi.org/10.1073/pnas.1808950116.
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Characterization of tumor metabolism with spatial information contributes to our understanding of complex cancer metabolic reprogramming, facilitating the discovery of potential metabolic vulnerabilities that might be targeted for tumor therapy. However, given the metabolic variability and flexibility of tumors, it is still challenging to characterize global metabolic alterations in heterogeneous cancer. Here, we propose a spatially resolved metabolomics approach to discover tumor-associated metabolites and metabolic enzymes directly in their native state. A variety of metabolites localized in different metabolic pathways were mapped by airflow-assisted desorption electrospray ionization mass spectrometry imaging (AFADESI-MSI) in tissues from 256 esophageal cancer patients. In combination with in situ metabolomics analysis, this method provided clues into tumor-associated metabolic pathways, including proline biosynthesis, glutamine metabolism, uridine metabolism, histidine metabolism, fatty acid biosynthesis, and polyamine biosynthesis. Six abnormally expressed metabolic enzymes that are closely associated with the altered metabolic pathways were further discovered in esophageal squamous cell carcinoma (ESCC). Notably, pyrroline-5-carboxylate reductase 2 (PYCR2) and uridine phosphorylase 1 (UPase1) were found to be altered in ESCC. The spatially resolved metabolomics reveal what occurs in cancer at the molecular level, from metabolites to enzymes, and thus provide insights into the understanding of cancer metabolic reprogramming.
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Yildiz, Ibrahim. « Computational insights on the hydride and proton transfer mechanisms of L-proline dehydrogenase ». PLOS ONE 18, no 11 (15 novembre 2023) : e0290901. http://dx.doi.org/10.1371/journal.pone.0290901.
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L-Proline dehydrogenase (ProDH) is a flavin-dependent oxidoreductase, which catalyzes the oxidation of L-proline to (S)-1-pyrroline-5-carboxylate. Based on the experimental studies, a stepwise proton and hydride transfer mechanism is supported. According to this mechanism, the amino group of L-proline is deprotonated by a nearby Lys residue, which is followed by the hydride transfer process from C5 position of L-proline to N5 position of isoalloxazine ring of FAD. It was concluded that the hydride transfer step is rate limiting in the reductive half-reaction, however, in the overall reaction, the oxidation of FAD is the rate limiting step. In this study, we performed a computational mechanistic investigation based on ONIOM method to elucidate the mechanism of the reductive half-reaction corresponding to the oxidation of L-proline into iminoproline. Our calculations support the stepwise mechanism in which the deprotonation occurs initially as a fast step as result of a proton transfer from L-proline to the Lys residue. Subsequently, a hydride ion transfers from L-proline to FAD with a higher activation barrier. The enzyme-product complex showed a strong interaction between reduced FAD and iminoproline, which might help to explain why a step in the oxidative half-reaction is rate-limiting.
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DelVecchio, Vito G., Joseph P. Connolly, Timothy G. Alefantis, Alexander Walz, Marian A. Quan, Guy Patra, John M. Ashton et al. « Proteomic Profiling and Identification of Immunodominant Spore Antigens of Bacillus anthracis, Bacillus cereus, and Bacillus thuringiensis ». Applied and Environmental Microbiology 72, no 9 (septembre 2006) : 6355–63. http://dx.doi.org/10.1128/aem.00455-06.
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ABSTRACT Differentially expressed and immunogenic spore proteins of the Bacillus cereus group of bacteria, which includes Bacillus anthracis, Bacillus cereus, and Bacillus thuringiensis, were identified. Comparative proteomic profiling of their spore proteins distinguished the three species from each other as well as the virulent from the avirulent strains. A total of 458 proteins encoded by 232 open reading frames were identified by matrix-assisted laser desorption ionization-time-of-flight mass spectrometry analysis for all the species. A number of highly expressed proteins, including elongation factor Tu (EF-Tu), elongation factor G, 60-kDa chaperonin, enolase, pyruvate dehydrogenase complex, and others exist as charge variants on two-dimensional gels. These charge variants have similar masses but different isoelectric points. The majority of identified proteins have cellular roles associated with energy production, carbohydrate transport and metabolism, amino acid transport and metabolism, posttranslational modifications, and translation. Novel vaccine candidate proteins were identified using B. anthracis polyclonal antisera from humans postinfected with cutaneous anthrax. Fifteen immunoreactive proteins were identified in B. anthracis spores, whereas 7, 14, and 7 immunoreactive proteins were identified for B. cereus and in the virulent and avirulent strains of B. thuringiensis spores, respectively. Some of the immunodominant antigens include charge variants of EF-Tu, glyceraldehyde-3-phosphate dehydrogenase, dihydrolipoamide acetyltransferase, Δ-1-pyrroline-5-carboxylate dehydrogenase, and a dihydrolipoamide dehydrogenase. Alanine racemase and neutral protease were uniquely immunogenic to B. anthracis. Comparative analysis of the spore immunome will be of significance for further nucleic acid- and immuno-based detection systems as well as next-generation vaccine development.
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Lewoniewska, Sylwia, Ilona Oscilowska, Antonella Forlino et Jerzy Palka. « Understanding the Role of Estrogen Receptor Status in PRODH/POX-Dependent Apoptosis/Survival in Breast Cancer Cells ». Biology 10, no 12 (10 décembre 2021) : 1314. http://dx.doi.org/10.3390/biology10121314.
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It has been suggested that activation of estrogen receptor α (ER α) stimulates cell proliferation. In contrast, estrogen receptor β (ER β) has anti-proliferative and pro-apoptotic activity. Although the role of estrogens in estrogen receptor-positive breast cancer progression has been well established, the mechanism of their effect on apoptosis is not fully understood. It has been considered that ER status of breast cancer cells and estrogen availability might determine proline dehydrogenase/proline oxidase (PRODH/POX)-dependent apoptosis. PRODH/POX is a mitochondrial enzyme that converts proline into pyrroline-5-carboxylate (P5C). During this process, ATP (adenosine triphosphate) or ROS (reactive oxygen species) are produced, facilitating cell survival or death, respectively. However, the critical factor in driving PRODH/POX-dependent functions is proline availability. The amount of this amino acid is regulated at the level of prolidase (proline releasing enzyme), collagen biosynthesis (proline utilizing process), and glutamine, glutamate, α-ketoglutarate, and ornithine metabolism. Estrogens were found to upregulate prolidase activity and collagen biosynthesis. It seems that in estrogen receptor-positive breast cancer cells, prolidase supports proline for collagen biosynthesis, limiting its availability for PRODH/POX-dependent apoptosis. Moreover, lack of free proline (known to upregulate the transcriptional activity of hypoxia-inducible factor 1, HIF-1) contributes to downregulation of HIF-1-dependent pro-survival activity. The complex regulatory mechanism also involves PRODH/POX expression and activity. It is induced transcriptionally by p53 and post-transcriptionally by AMPK (AMP-activated protein kinase), which is regulated by ERs. The review also discusses the role of interconversion of proline/glutamate/ornithine in supporting proline to PRODH/POX-dependent functions. The data suggest that PRODH/POX-induced apoptosis is dependent on ER status in breast cancer cells.
Thèses sur le sujet "Pyrroline-5-carboxylate complex"
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Zheng, Yao. « Identification of interacting mitochondrial enzymes involved in pyrroline-5-carboxylate metabolism in Arabidopsis thaliana ». Electronic Thesis or Diss., Sorbonne université, 2021. https://accesdistant.sorbonne-universite.fr/login?url=https://theses-intra.sorbonne-universite.fr/2021SORUS269.pdf.
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La proline, acide aminé protéinogène, joue un rôle crucial dans le métabolisme cellulaire. Dans les mitochondries, la proline est oxydée en glutamate par l'action séquentielle de la proline déshydrogénase (ProDH) et de la pyrroline-5-carboxylate (P5C) déshydrogénase (P5CDH). L'ornithine-δ-aminotransférase (δOAT) participe également à la formation de P5C via la conversion de l'ornithine et de l’α -cétoglutarate en glutamate et P5C. L’utilisation de mutants et d’approches biochimiques a révélé que ProDH1, P5CDH et δOAT sont impliquées dans la sénescence des feuilles induite à l'obscurité (DIS) chez Arabidopsis thaliana. Une accumulation importante de P5C et de proline est observée chez le mutant p5cdh et, dans une moindre mesure chez le mutant prodh1prodh2, suggérant un cycle proline-P5C. Les mutants prodh1prodh2 et p5cdh ont un profil métabolomique similaire qui diffère de celui du WT et de oat, démontrant ainsi le rôle de l'oxydation de la proline au cours de la sénescence. Nous avons montré que ProDH1 est essentiellement associée à la membrane mitochondriale, tandis que P5CDH et δOAT sont plus uniformément réparties entre la matrice et la membrane. L’oligomérisation de ProDH1, P5CDH et δOAT a été révélée à l'aide d’une analyse de complémentation bimoléculaire de fluorescence (BiFC). Les interactions entre ces enzymes du métabolisme du P5C ont été confirmées par des approches de protéomique couplée à la MS en condition de sénescence chez A. thaliana. Ces trois enzymes forment un(des) complexe(s) impliqué(s) dans l'oxydation de la proline pour alimenter la chaîne de transfert d'électrons mitochondriale afin de pourvoir aux besoins énergétiques des cellules sénescentesThe proteinogenic amino acid proline plays a crucial role for cellular metabolism in living organisms. In mitochondria, proline is oxidized to glutamate by the sequential action of proline dehydrogenase (ProDH) and pyrroline-5-carboxylate (P5C) dehydrogenase (P5CDH). In addition, ornithine δ-aminotransferase (δOAT) also participates in P5C formation through the conversion of ornithine and α-ketoglutarate into glutamate and P5C. Using mutants and biochemical approaches, ProDH1, P5CDH and δOAT were shown to be involved during dark-induced leaf senescence (DIS) in Arabidopsis thaliana. Striking accumulation of P5C and proline was observed in p5cdh mutant and to a lesser extent in prodh1prodh2 mutant, suggesting a putative proline-P5C cycle. Metabolomic analysis indicated that prodh1prodh2 and p5cdh have a similar metabolomic profile, but significantly different from wild-type and oat mutant, demonstrating the role of proline oxidation during DIS. ProDH1 was shown to be preferentially associated to the mitochondrial membrane fraction, while P5CDH and δOAT are more evenly distributed between matrix and membrane fractions. Homo- and hetero-oligomerizations of ProDH1, P5CDH, and δOAT were revealed using Bimolecular Fluorescence Complementation (BiFC) assay of infiltrated tobacco leaves. Interactions between P5C metabolism enzymes were further highlighted in DIS leaves using proteomics approaches coupled with mass spectrometry. Our work demonstrates that these three enzymes form P5C metabolic complex(es) involved in the oxidation of proline to fuel mitochondrial electron transfer chain to support the energy needs of senescent cells
Chapitres de livres sur le sujet "Pyrroline-5-carboxylate complex"
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Li, Peng, et Guoyao Wu. « Characteristics of Nutrition and Metabolism in Dogs and Cats ». Dans Nutrition and Metabolism of Dogs and Cats, 55–98. Cham : Springer Nature Switzerland, 2024. http://dx.doi.org/10.1007/978-3-031-54192-6_4.
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AbstractDomestic dogsand cats have evolved differentially in some aspects of nutrition, metabolism, chemical sensing, and feedingbehavior. The dogs have adapted to omnivorous dietscontaining taurine-abundant meat and starch-rich plant ingredients. By contrast, domestic catsmust consumeanimal-sourced foodsfor survival, growth, and development. Both dogsand catssynthesize vitamin C and many amino acids (AAs, such as alanine, asparagine, aspartate, glutamate, glutamine, glycine, proline, and serine), but have a limited ability to form de novo arginineand vitamin D3. Compared with dogs, cats have greater endogenousnitrogen losses and higher dietary requirements for AAs (particularly arginine, taurine, and tyrosine), B-complex vitamins (niacin, thiamin, folate, and biotin), and choline; exhibit greater rates of gluconeogenesis; are less sensitive to AA imbalances and antagonism; are more capable of concentrating urine through renal reabsorption of water; and cannot tolerate high levels of dietary starch due to limited pancreatic α-amylase activity. In addition, dogs can form sufficient taurinefrom cysteine(for most breeds); arachidonic acidfrom linoleic acid; eicosapentaenoic acid and docosahexaenoic acid from α-linolenic acid; all-trans-retinol from β-carotene; and niacinfrom tryptophan. These synthetic pathways, however, are either absent or limited in all cats due to (a) no or low activities of key enzymes (including pyrroline-5-carboxylate synthase, cysteinedioxygenase, ∆6-desaturase, β-carotene dioxygenase, and quinolinate phosphoribosyltransferase) and (b) diversion of intermediates to other metabolic pathways. Dogs can thrive on one large meal daily, select high-fat over low-fat diets, and consume sweet substances. By contrast, cats eat more frequently during light and dark periods, select high-protein over low-protein diets, refuse dryfood, enjoy a consistent diet, and cannot taste sweetness. This knowledge guides the feeding and care of dogsand cats, as well as the manufacturing of their foods. As abundant sources of essentialnutrients, animal-derivedfoodstuffs play important roles in optimizing the growth, development, and health of the companionanimals.