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Journal of Equine Veterinary Science Jun 2021The aim of this study was to evaluate the effects of L-proline on the extender quality of frozen and post-thawed jackass semen. Jackass (n = 6) semen samples were...
The aim of this study was to evaluate the effects of L-proline on the extender quality of frozen and post-thawed jackass semen. Jackass (n = 6) semen samples were collected and cryopreserved in gradient concentrations (0-80 mM) of L-proline in extenders; post-thawed semen samples were cultured in L-proline medium for 10 hours at 37°C. For cryopreservation experiment I, the motile parameters, mitochondrial membrane potential (MMP), and plasma membrane, acrosome, and chromatin structure integrities of post-thawed semen were assessed. For culture experiment II, additional ROS contents were analyzed after incubation. For the fertility trial, jennies (n = 135) were divided into group I (30 mM L-proline in cryopreservation extender), group II (40 mM L-proline in culture medium), and the control. Pregnancy was diagnosed using an ultrasound scanner 30 days after ovulation. The results of experiment I showed that, motile parameters and acrosome and chromatin structure integrities of groups I and 40 mM were significantly higher than the control (P < .05). MMP of group I was significantly higher than the control and 40 mM groups (P < .05). In experiment II, after 4 hours of incubation, motile parameters, MMP, and DNA integrity in group II were significantly higher than the control (P < .05). Additionally, 40 and 80 mM L-proline in culture medium significantly reduced ROS accumulation after 4 and 10 hours of incubation (P < .05). Pregnancy rates of the control and groups I and II were 28.85%, 40%, and 36.84%, respectively. In conclusion, the extenders containing 30 to 40 mM L-proline improved both qualities of frozen and post-thawed semen, and it will be a beneficial agent for donkey frozen spermatozoa or post-thawed semen storage.
Topics: Animals; Cryopreservation; Cryoprotective Agents; Equidae; Female; Male; Pregnancy; Proline; Semen; Semen Preservation
PubMed: 33993948
DOI: 10.1016/j.jevs.2021.103393 -
Yeast (Chichester, England) Sep 2020Proline is a predominant amino acid in grape must, but it is poorly utilized by the yeast Saccharomyces cerevisiae in wine-making processes. This sometimes leads to a...
Proline is a predominant amino acid in grape must, but it is poorly utilized by the yeast Saccharomyces cerevisiae in wine-making processes. This sometimes leads to a nitrogen deficiency during fermentation and proline accumulation in wine. Although the presence of other nitrogen sources under fermentation conditions is likely to interfere with proline utilization, the inhibitory mechanisms of proline utilization remain unclear. In this study, we examined the effect of arginine on proline utilization in S. cerevisiae. We first constructed a proline auxotrophic yeast strain and identified an inhibitory factor by observing the growth of cells when proline was present as a sole nitrogen source. Intriguingly, we found that arginine, and not ammonium ion, clearly inhibited the growth of proline auxotrophic cells. In addition, arginine prevented the proline consumption of wild-type and proline auxotrophic cells, indicating that arginine is an inhibitory factor of proline utilization in yeast. Next, quantitative polymerase chain reaction (PCR) analysis showed that arginine partially repressed the expression of genes involved in proline degradation and uptake. We then observed that arginine induced the endocytosis of the proline transporters Put4 and Gap1, whereas ammonium induced the endocytosis of only Gap1. Hence, our results may involve an important mechanism for arginine-mediated inhibition of proline utilization in yeast. The breeding of yeast that utilizes proline efficiently could be promising for the improvement of wine quality.
Topics: Ammonium Compounds; Arginine; Fermentation; Nitrogen; Proline; Saccharomyces cerevisiae; Saccharomyces cerevisiae Proteins; Wine
PubMed: 32557770
DOI: 10.1002/yea.3504 -
Plant Physiology and Biochemistry : PPB Jun 2020Proline accumulation and metabolism are associated with mechanisms of abiotic stress avoidance in plants. Proline accumulation generally improves osmotic stress...
Proline accumulation and metabolism are associated with mechanisms of abiotic stress avoidance in plants. Proline accumulation generally improves osmotic stress tolerance whereas proline metabolism can have varying effects from ATP generation to the formation of reactive oxygen species. To further understand the roles of proline in stress protection, two peanut cultivars with contrasting tolerance to drought were examined by transcriptional and biochemical analyses during water stress. Plants exposed to polyethylene glycol had diminished relative water content and increased proline content; while, only the drought sensitive plants, cultivar Granoleico, showed lipid oxidative damage (measured as thiobarbituric acid reactive substances). The expression of proline biosynthesis genes (P5CS1, P5CS2a, P5CS2b, P5CR) was increased in both cultivars upon exposure to water stress. However, the relative expression of proline catabolism genes (ProDH1, ProDH2) was increased only in the sensitive cultivar during stress. Exogenous addition of proline and the proline analogue thiazolidine-4-carboxylic acid (T4C), both substrates of proline dehydrogenase, was also used to exacerbate and identify plant responses. Pretreatment of plants with T4C induced unique changes in the drought tolerant EC-98 cultivar such as higher mRNA levels of proline biosynthetic and catabolic ProDH genes, even in the absence of water stress. The increased levels of ProDH gene expression, potentially associated with higher T4C conversion to cysteine, may contribute to the tolerant phenotype.
Topics: Arachis; Droughts; Gene Expression Regulation, Plant; Proline; Stress, Physiological; Water
PubMed: 32320942
DOI: 10.1016/j.plaphy.2020.04.010 -
Journal of the American Society For... Aug 2023The fragmentation characteristics of ions produced from proline-containing heptapeptides have been studied in detail. The study has utilized the following C-terminally...
The fragmentation characteristics of ions produced from proline-containing heptapeptides have been studied in detail. The study has utilized the following C-terminally amidated model peptides: PA, APA, APA, APA, APA, APA, AP, PYAGFLV, PAGFLVY, PGFLVYA, PFLVYAG, PLVYAGF, PVYAGFL, YPAGFLV, YAPGFLV, YAGPFLV, YAGFPLV, YAGFLPV, YAGFLVP, PYAFLVG, PVLFYAG, APXA, and AXPA (where X = C, D, F, G, L, V, and Y, respectively). The results have shown that ions undergo head-to-tail cyclization and form a macrocyclic structure. Under the collision-induced dissociation (CID) condition, it generates nondirect sequence ions regardless of the position of the proline and the neighboring amino acid residues. This study highlights the unusual and unique fragmentation behavior of proline-containing heptapeptides. Following the head-to-tail cyclization, the ring opens up and places the proline residue in the N-terminal position while forming a regular oxazolone form of ions for all peptide series. Then, the fragmentation reaction pathway is followed by the elimination of proline with its C-terminal neighbor residue as an oxazolone (e.g., PX) for all proline-containing peptide series.
Topics: Oxazolone; Proline; Peptides; Ions; Cyclization
PubMed: 37402129
DOI: 10.1021/jasms.3c00049 -
Lancet (London, England) Feb 2022
Topics: COVID-19 Testing; Developing Countries; Drug Combinations; Global Health; Health Services Accessibility; Humans; Lactams; Leucine; Nitriles; Proline; Ritonavir; COVID-19 Drug Treatment
PubMed: 35219388
DOI: 10.1016/S0140-6736(22)00372-5 -
International Journal of Molecular... Dec 2022Carbon nanoparticles have potential threats to plant growth and stress tolerance. The polyhydroxy fullerene-fullerol (one of the carbon nanoparticles) could increase...
Carbon nanoparticles have potential threats to plant growth and stress tolerance. The polyhydroxy fullerene-fullerol (one of the carbon nanoparticles) could increase biomass accumulation in several plants subjected to drought; however, the underlying molecular and metabolic mechanisms governed by fullerol in improving drought tolerance in remain unclear. In the present study, exogenous fullerol was applied to the leaves of seedlings under drought conditions. The results of transcriptomic and metabolomic analyses revealed changes in the molecular and metabolic profiles of . The differentially expressed genes and the differentially accumulated metabolites, induced by drought or fullerol treatment, were mainly enriched in the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways related to carbohydrate metabolism (e.g., "carbon metabolism" and "galactose metabolism"), amino acid metabolism (e.g., "biosynthesis of amino acids" and "arginine and proline metabolism"), and secondary metabolite metabolism (e.g., "biosynthesis of secondary metabolites"). For carbohydrate metabolism, the accumulation of oligosaccharides (e.g., sucrose) was decreased, whereas that of monosaccharides (e.g., mannose and myo-inositol) was increased by drought. With regard to amino acid metabolism, under drought stress, the accumulation of amino acids such as phenylalanine and tryptophan decreased, whereas that of glutamate and proline increased. Further, for secondary metabolite metabolism, subjected to soil drying showed a reduction in phenolics and flavonoids, such as hyperoside and trans-3-coumaric acid. However, the accumulation of carbohydrates was almost unchanged in fullerol-treated subjected to drought. When exposed to water shortage, the accumulation of amino acids, such as proline, was decreased upon fullerol treatment. However, that of phenolics and flavonoids, such as luteolin and trans-3-coumaric acid, was enhanced. Our findings suggest that fullerol can alleviate the inhibitory effects of drought on phenolics and flavonoids to enhance drought tolerance in .
Topics: Brassica napus; Drought Resistance; Stress, Physiological; Droughts; Proline; Carbon; Gene Expression Regulation, Plant
PubMed: 36499633
DOI: 10.3390/ijms232315304 -
Journal of Bacteriology Jun 2022The Gram-positive pathogen Staphylococcus aureus is the only bacterium known to synthesize arginine from proline via the arginine-proline interconversion pathway despite...
The Gram-positive pathogen Staphylococcus aureus is the only bacterium known to synthesize arginine from proline via the arginine-proline interconversion pathway despite having genes for the well-conserved glutamate pathway. Since the proline-arginine interconversion pathway is repressed by CcpA-mediated carbon catabolite repression (CCR), CCR has been attributed to the arginine auxotrophy of S. aureus. Using ribose as a secondary carbon source, here, we demonstrate that S. aureus arginine auxotrophy is not due to CCR but due to the inadequate concentration of proline degradation product. Proline is degraded by proline dehydrogenase (PutA) into pyrroline-5-carboxylate (P5C). Although the PutA expression was fully induced by ribose, the P5C concentration remained insufficient to support arginine synthesis because P5C was constantly consumed by the P5C reductase ProC. When the P5C concentration was artificially increased by either PutA overexpression or deletion, S. aureus could synthesize arginine from proline regardless of carbon source. In contrast, when the P5C concentration was reduced by overexpression of , it inhibited the growth of the deletion mutant without arginine. Intriguingly, the ectopic expression of the glutamate pathway enzymes converted S. aureus into arginine prototroph. In an animal experiment, the arginine-proline interconversion pathway was not required for the survival of S. aureus. Based on these results, we concluded that S. aureus does not synthesize arginine from proline under physiological conditions. We also propose that arginine auxotrophy of S. aureus is not due to the CcpA-mediated CCR but due to the inactivity of the conserved glutamate pathway. Staphylococcus aureus is a versatile Gram-positive human pathogen infecting various human organs. The bacterium's versatility is partly due to efficient metabolic regulation via the carbon catabolite repression system (CCR). S. aureus is known to interconvert proline and arginine, and CCR represses the synthesis of both amino acids. However, when CCR is released by a nonpreferred carbon source, S. aureus can synthesize proline but not arginine. In this study, we show that, in S. aureus, the intracellular concentration of pyrroline-5-carboxylate (P5C), the degradation product of proline and the substrate of proline synthesis, is too low to synthesize arginine from proline. These results call into question the notion that S. aureus synthesizes arginine from proline.
Topics: Animals; Arginine; Carbon; Glutamic Acid; Mutation; Proline; Ribose; Staphylococcal Infections; Staphylococcus aureus
PubMed: 35546540
DOI: 10.1128/jb.00018-22 -
Aging Cell Feb 2021Infertility is an increasingly common health issue, with rising prevalence in advanced parental age. Environmental stress has established negative effects on...
Infertility is an increasingly common health issue, with rising prevalence in advanced parental age. Environmental stress has established negative effects on reproductive health, however, the impact of altering cellular metabolism and its endogenous reactive oxygen species (ROS) on fertility remains unclear. Here, we demonstrate the loss of proline dehydrogenase, the first committed step in proline catabolism, is relatively benign. In contrast, disruption of alh-6, which facilitates the second step of proline catabolism by converting 1-pyrroline-5-carboxylate (P5C) to glutamate, results in premature reproductive senescence, specifically in males. The premature reproductive senescence in alh-6 mutant males is caused by aberrant ROS homeostasis, which can be countered by genetically limiting the first committed step of proline catabolism that functions upstream of ALH-6 or by pharmacological treatment with antioxidants. Taken together, our work uncovers proline metabolism as a critical component of normal sperm function that can alter the rate of aging in the male reproductive system.
Topics: Animals; Caenorhabditis elegans; Cellular Senescence; Germ Cells; Male; Proline; Spermatozoa
PubMed: 33480139
DOI: 10.1111/acel.13308 -
Genes & Development May 2023DROSHA serves as a gatekeeper of the microRNA (miRNA) pathway by processing primary transcripts (pri-miRNAs). While the functions of structured domains of DROSHA have...
DROSHA serves as a gatekeeper of the microRNA (miRNA) pathway by processing primary transcripts (pri-miRNAs). While the functions of structured domains of DROSHA have been well documented, the contribution of N-terminal proline-rich disordered domain (PRD) remains elusive. Here we show that the PRD promotes the processing of miRNA hairpins located within introns. We identified a DROSHA isoform (p140) lacking the PRD, which is produced by proteolytic cleavage. Small RNA sequencing revealed that p140 is significantly impaired in the maturation of intronic miRNAs. Consistently, our minigene constructs demonstrated that PRD enhances the processing of intronic hairpins, but not those in exons. Splice site mutations did not affect the PRD's enhancing effect on intronic constructs, suggesting that the PRD acts independently of splicing reaction by interacting with sequences residing within introns. The N-terminal regions from zebrafish and DROSHA can replace the human counterpart, indicating functional conservation despite poor sequence alignment. Moreover, we found that rapidly evolving intronic miRNAs are generally more dependent on PRD than conserved ones, suggesting a role of PRD in miRNA evolution. Our study reveals a new layer of miRNA regulation mediated by a low-complexity disordered domain that senses the genomic contexts of miRNA loci.
Topics: Animals; Humans; Introns; MicroRNAs; Proline; Ribonuclease III; RNA Processing, Post-Transcriptional; Zebrafish
PubMed: 37236670
DOI: 10.1101/gad.350275.122 -
Journal of Natural Products Jun 2022Aureobasidin A (abA) is a natural depsipeptide that inhibits inositol phosphorylceramide (IPC) synthases with significant broad-spectrum antifungal activity. abA is... (Review)
Review
Aureobasidin A (abA) is a natural depsipeptide that inhibits inositol phosphorylceramide (IPC) synthases with significant broad-spectrum antifungal activity. abA is known to have two distinct conformations in solution corresponding to and -proline (Pro) amide bond rotamers. While the -Pro conformation has been studied extensively, -Pro conformers have remained elusive. Conformational properties of cyclic peptides are known to strongly affect both potency and cell permeability, making a comprehensive characterization of abA conformation highly desirable. Here, we report a high-resolution 3D structure of the -Pro conformer of aureobasidin A elucidated for the first time using a recently developed NMR-driven computational approach. This approach utilizes ForceGen's advanced conformational sampling of cyclic peptides augmented by sparse distance and torsion angle constraints derived from NMR data. The obtained 3D conformational structure of -Pro abA has been validated using anisotropic residual dipolar coupling measurements. Support for the biological relevance of both the -Pro and -Pro abA configurations was obtained through molecular similarity experiments, which showed a significant 3D similarity between NMR-restrained abA conformational ensembles and another IPC synthase inhibitor, pleofungin A. Such ligand-based comparisons can further our understanding of the important steric and electrostatic characteristics of abA and can be utilized in the design of future therapeutics.
Topics: Depsipeptides; Peptides, Cyclic; Proline; Protein Conformation
PubMed: 35622967
DOI: 10.1021/acs.jnatprod.1c01071