scholarly journals Isolation and characterization of key genes that promote flavonoid accumulation in purple-leaf tea (Camellia sinensis L.)

2017 ◽  
Author(s):  
Xiujuan He ◽  
Xuecheng Zhao ◽  
Liping Gao ◽  
Xingxing Shi ◽  
Xinlong Dai ◽  
...  
Keyword(s):  
Transgenic Tobacco ◽  
Molecular Mechanisms ◽  
Tea Plant ◽  
Hybrid Population ◽  
Myb Transcription Factor ◽  
Isolation And Characterization ◽  
Young Leaves ◽  
High Concentrations ◽  
Purple Leaf

AbstractThere were several high concentrations of flavonoid components in tea leaves that present health benefits. A novel purple-leaf tea variety, ‘Mooma1’, was obtained from the natural hybrid population of Longjing 43 variety. The buds and young leaves of ‘Mooma1’ were displayed in bright red. HPLC and LC-MS analysis showed that anthocyanins and O-Glycosylated flavonols were remarkably accumulated in the leaves of ‘Mooma1’, while the total amount of catechins in purple-leaf leaves was slightly decreased compared with the control. A R2R3-MYB transcription factor (CsMYB6A) and a novel UGT gene (CsUGT72AM1), that were highly expressed in purple leaf were isolated and identified by transcriptome sequencing. The over-expression of transgenic tobacco confirmed that CsMYB6A can activate the expression of flavonoid-related structural genes, especially CHS and 3GT, controlling the accumulation of anthocyanins in the leaf of transgenic tobacco. Enzymatic assays in vitro confirmed that CsUGT72AM1 has catalytic activity as a flavonol 3-O-glucosyltransferase, and displayed broad substrate specificity. The results were useful for further elucidating the molecular mechanisms of the flavonoid metabolic fluxes in the tea plant.

scholarly journals Phosphodiesterase-1 Inhibitory Activity of Two Flavonoids Isolated fromPistacia integerrimaJ. L. Stewart Galls

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Abdur Rauf ◽  
Muhammad Saleem ◽  
Ghias Uddin ◽  
Bina S. Siddiqui ◽  
Haroon Khan ◽  
...  
Keyword(s):  
Inhibitory Activity ◽  
In Silico ◽  
Molecular Mechanisms ◽  
Methanolic Extract ◽  
Chemical Constituents ◽  
Folk Medicine ◽  
Chemical Characterization ◽  
Active Constituents ◽  
Isolation And Characterization

Pistacia integerrimais one of twenty species among the genusPistacia. Long horn-shaped galls that develop on this plant are harvested and used in Ayurveda and Indian traditional medicine to make “karkatshringi”, a herbal medicine used for the treatment of asthma and different disorders of respiratory tract. However, until now, the molecular mechanisms of action of “karkatshringi” and its chemical characterization are partially known. This study deals with the isolation and characterization of the active constituents from the methanolic extract ofP. integerrimagalls and it was also oriented to evaluatein vitroandin silicotheir potential enzymatic inhibitory activity against phosphodiesterase-1 (PDE1), a well-known enzyme involved in airway smooth muscle activity and airway inflammation. Our results showed that the methanolic extract ofP. integerrimagalls and some of its active constituents [naringenin (1) and 3,5,7,4′-tetrahydroxy-flavanone (2)] are ablein vitroto inhibit PDE1 activity (59.20 ± 4.95%, 75.90 ± 5.90%, and 65.25 ± 5.25%, resp.) and demonstratein silicoan interesting interaction with this enzymatic site. Taken together, our results add new knowledge of chemical constituents responsible for the biological activity ofP. integerrimaand contextually legitimate the use of this plant in folk medicine.

scholarly journals Isolation and characterization of a novel temperate Escherichia coli bacteriophage, Kapi1, which modifies the O-antigen and contributes to the competitiveness of its host during colonization of the murine gastrointestinal tract.

2021 ◽  
Author(s):  
Kat Pick ◽  
Tingting Ju ◽  
Benjamin P. Willing ◽  
Tracy Lyn Raivio
Keyword(s):  
Escherichia Coli ◽  
Gastrointestinal Tract ◽  
Molecular Mechanisms ◽  
Shigella Flexneri ◽  
Simulated Intestinal Fluid ◽  
O Antigen ◽  
Isolation And Characterization

In this study, we describe the isolation and characterization of novel bacteriophage vB_EcoP_Kapi1 (Kapi1) isolated from a strain of commensal Escherichia coli inhabiting the gastrointestinal tract of healthy mice. We show that Kapi1 is a temperate phage integrated into tRNA argW of strain MP1 and describe its genome annotation and structure. Kapi1 shows limited homology to other characterized prophages but is most similar to the seroconverting phages of Shigella flexneri, and clusters taxonomically with P22-like phages. The receptor for Kapi1 is the lipopolysaccharide O-antigen, and we further show that Kapi1 alters the structure of its hosts O-antigen in multiple ways.  Kapi1 displays unstable lysogeny, and we find that lysogeny is favored during growth in simulated intestinal fluid. Furthermore, Kapi1 lysogens have a competitive advantage over their non-lysogenic counterparts both in vitro and in vivo, suggesting a role for Kapi1 during colonization. We thus report the use of MP1 and Kapi1 as a model system to explore the molecular mechanisms of mammalian colonization by E. coli to ask what the role(s) of prophages in this context might be.

scholarly journals A proteinaceous organic matrix regulates carbonate mineral production in the marine teleost intestine

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Kevin L. Schauer ◽  
Christophe M. R. LeMoine ◽  
Adrian Pelin ◽  
Nicolas Corradi ◽  
M. Danielle McDonald ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Organic Matrix ◽  
Magnesium Content ◽  
Inhibitory Effect ◽  
Marine Teleost ◽  
Low Concentrations ◽  
The Matrix ◽  
Mineral Production ◽  
High Concentrations

AbstractMarine teleost fish produce CaCO3in their intestine as part of their osmoregulatory strategy. This precipitation is critical for rehydration and survival of the largest vertebrate group on earth, yet the molecular mechanisms that regulate this reaction are unknown. Here, we isolate and characterize an organic matrix associated with the intestinal precipitates produced by Gulf toadfish (Opsanus beta). Toadfish precipitates were purified using two different methods, and the associated organic matrix was extracted. Greater than 150 proteins were identified in the isolated matrix by mass spectrometry and subsequent database searching using anO. betatranscriptomic sequence library produced here. Many of the identified proteins were enriched in the matrix compared to the intestinal fluid, and three showed no substantial homology to any previously characterized protein in the NCBI database. To test the functionality of the isolated matrix, a micro-modifiedin vitrocalcification assay was designed, which revealed that low concentrations of isolated matrix substantially promoted CaCO3production, where high concentrations showed an inhibitory effect. High concentrations of matrix also decreased the incorporation of magnesium into the forming mineral, potentially providing an explanation for the variability in magnesium content observed in precipitates produced by different fish species.

scholarly journals Comparison of Different Commercial Nanopolystyrenes: Behavior in Exposure Media, Effects on Immune Function and Early Larval Development in the Model Bivalve Mytilus galloprovincialis

Nanomaterials ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 3291
Author(s):  
Manon Auguste ◽  
Teresa Balbi ◽  
Angelica Miglioli ◽  
Stefano Alberti ◽  
Sonja Prandi ◽  
...  
Keyword(s):  
Immune Function ◽  
Larval Development ◽  
Molecular Mechanisms ◽  
Sea Water ◽  
Biological Effects ◽  
Marine Bivalve ◽  
Isolation And Characterization ◽  
Early Larval Development

In the absence of standard methods for the detection/quantification of nanoplastics (NPs) in environmental samples, commercial nanopolymers are utilized as proxies for toxicity testing and environmental risk assessment. In marine species, a considerable amount of data are now available on the effects of nanopolystyrene (PS-NPs) of different size/surface characteristics. In this work, amino modified PS-NPs (PS-NH2) (50 and 100 nm), purchased from two different companies, were compared in terms of behavior in exposure media and of biological responses, from molecular to organism level, in the model marine bivalve Mytilus. Different PS-NH2 showed distinct agglomeration and surface charge in artificial sea water (ASW) and hemolymph serum (HS). Differences in behavior were largely reflected by the effects on immune function in vitro and in vivo and on early larval development. Stronger effects were generally observed with PS-NH2 of smaller size, showing less agglomeration and higher positive charge in exposure media. Specific molecular interactions with HS components were investigated by the isolation and characterization of the NP-corona proteins. Data obtained in larvae demonstrate interference with the molecular mechanisms of shell biogenesis. Overall, different PS-NH2 can affect the key physiological functions of mussels at environmental concentrations (10 µg/L). However, detailed information on the commercial NPs utilized is required to compare their biological effects among laboratory experiments.

Expression for Caffeine Biosynthesis and Related Enzymes in Camellia sinensis

2010 ◽  
Vol 65 (3-4) ◽  
pp. 245-256 ◽  
Author(s):  
Misako Kato ◽  
Naoko Kitao ◽  
Mariko Ishida ◽  
Hanayo Morimoto ◽  
Fumi Irino ◽  
...  
Keyword(s):  
Gene Expression ◽  
Camellia Sinensis ◽  
Heavy Metal Stress ◽  
Tea Plant ◽  
Purine Base ◽  
Caffeine Synthase ◽  
Purine Alkaloid ◽  
Young Leaves ◽  
Caffeine Biosynthesis ◽  
High Concentrations

Caffeine (1,3,7-trimethylxanthine) is a purine alkaloid that is present in high concentrations in the tea plant Camellia sinensis. Caffeine synthase (CS, EC 2.1.1.160) catalyzes the S-adenosyl-L-methionine-dependent N-3- and N-1-methylation of the purine base to form caffeine, the last step in the purine alkaloid biosynthetic pathway. We studied the expression profile of the tea caffeine synthase (TCS) gene in developing leaves and flowers by means of northern blot analysis, and compared it with those of phenylalanine ammonia lyase (PAL, EC 4.3.1.5), chalcone synthase (CHS, EC 2.3.1.74), and S-adenosyl-L-methionine synthase (SAMS, EC 2.5.1.6). The amount of TCS transcripts was highest in young leaves and declined markedly during leaf development, whereas it remained constant throughout the development of the flower. Environmental stresses other than heavy metal stress and plant hormone treatments had no effect on the expression of TCS genes, unlike the other three genes. Drought stress suppressed TCS gene expression in leaves, and the expression pattern mirrored that of the dehydrin gene. The amounts of TCS transcripts increased slightly on supply of a nitrogen source. We discuss the regulation of TCS gene expression

scholarly journals Resurrecting Van Leeuwenhoek's rotifers: a reappraisal of the role of disaccharides in anhydrobiosis

2003 ◽  
Vol 358 (1438) ◽  
pp. 1755-1771 ◽  
Author(s):  
A. Tunnacliffe ◽  
J. Lapinski
Keyword(s):  
Desiccation Tolerance ◽  
Molecular Mechanisms ◽  
18Th Century ◽  
Conclusive Evidence ◽  
Limited Information ◽  
Apparent Contradiction ◽  
Plant Seeds ◽  
High Concentrations ◽  
Brine Shrimp Cysts

In 1702, Van Leeuwenhoek was the first to describe the phenomenon of anhydrobiosis in a species of bdelloid rotifer, Philodina roseola . It is the purpose of this review to examine what has been learned since then about the extreme desiccation tolerance in rotifers and how this compares with our understanding of anhydrobiosis in other organisms. Remarkably, much of what is known today about the requirements for successful anhydrobiosis, and the degree of biostability conferred by the dry state, was already determined in principle by the time of Spallanzani in the late 18th century. Most modern research on anhydrobiosis has emphasized the importance of the non–reducing disaccharides trehalose and sucrose, one or other sugar being present at high concentrations during desiccation of anhydrobiotic nematodes, brine shrimp cysts, bakers' yeast, resurrection plants and plant seeds. These sugars are proposed to act as water replacement molecules, and as thermodynamic and kinetic stabilizers of biomolecules and membranes. In apparent contradiction of the prevailing models, recent experiments from our laboratory show that bdelloid rotifers undergo anhydrobiosis without producing trehalose or any analogous molecule. This has prompted us to critically re–examine the association of disaccharides with anhydrobiosis in the literature. Surprisingly, current hypotheses are based almost entirely on in vitro data: there is very limited information which is more than simply correlative in the literature on living systems. In many species, disaccharide accumulation occurs at approximately the same time as desiccation tolerance is acquired. However, several studies indicate that these sugars are not sufficient for anhydrobiosis; furthermore, there is no conclusive evidence, through mutagenesis or functional knockout experiments, for example, that sugars are necessary for anhydrobiosis. Indeed, some plant seeds and micro–organisms, like the rotifer, exhibit excellent desiccation tolerance in the absence of high intracellular sugar concentrations. Accordingly, it seems appropriate to call for a re–evaluation of our understanding of anhydrobiosis and to embark on new experimental programmes to determine the key molecular mechanisms involved.

High resolution mapping of nucleic acid containing complexes in vitro and in situ

1996 ◽  
Vol 54 ◽  
pp. 48-49
Author(s):  
D. P. Bazett-Jones ◽  
M. J. Hendzel
Keyword(s):  
Nucleic Acid ◽  
High Resolution ◽  
Transcription Initiation ◽  
Molecular Mechanisms ◽  
Heavy Atom ◽  
Regulation Of Transcription ◽  
High Exposure ◽  
Resolution Mapping ◽  
Tata Sequence

Structural analysis of combinations of nucleosomes and transcription factors on promoter and enhancer elements is necessary in order to understand the molecular mechanisms responsible for the regulation of transcription initiation. Such complexes are often not amenable to study by high resolution crystallographic techniques. We have been applying electron spectroscopic imaging (ESI) to specific problems in molecular biology related to transcription regulation. There are several advantages that this technique offers in studies of nucleoprotein complexes. First, an intermediate level of spatial resolution can be achieved because heavy atom contrast agents are not necessary. Second, mass and stoichiometric relationships of protein and nucleic acid can be estimated by phosphorus detection, an element in much higher proportions in nucleic acid than protein. Third, wrapping or bending of the DNA by the protein constituents can be observed by phosphorus mapping of the complexes. Even when ESI is used with high exposure of electrons to the specimen, important macromolecular information may be provided. For example, an image of the TATA binding protein (TBP) bound to DNA is shown in the Figure (top panel). It can be seen that the protein distorts the DNA away from itself and much of its mass sits off the DNA helix axis. Moreover, phosphorus and mass estimates demonstrate whether one or two TBP molecules interact with this particular promoter TATA sequence.

In Vitro Effects of Ethanol on Rabbit Platelet Aggregation, Secretion of Granule Contents, and Cyclic AMP Levels in the Presence of Prostacyclin

1989 ◽  
Vol 61 (02) ◽  
pp. 254-258 ◽  
Author(s):  
Margaret L Rand ◽  
Peter L Gross ◽  
Donna M Jakowec ◽  
Marian A Packham ◽  
J Fraser Mustard
Keyword(s):  
Cyclic Amp ◽  
Inhibitory Effect ◽  
Rabbit Platelet ◽  
Inhibitory Effects ◽  
Low Concentrations ◽  
Rabbit Platelets ◽  
High Concentrations ◽  
In Vitro Effects ◽  
Aggregation Of Platelets

SummaryEthanol, at physiologically tolerable concentrations, inhibits platelet responses to low concentrations of collagen or thrombin, but does not inhibit responses of washed rabbit platelets stimulated with high concentrations of ADP, collagen, or thrombin. However, when platelet responses to high concentrations of collagen or thrombin had been partially inhibited by prostacyclin (PGI2), ethanol had additional inhibitory effects on aggregation and secretion. These effects were also observed with aspirin- treated platelets stimulated with thrombin. Ethanol had no further inhibitory effect on aggregation of platelets stimulated with ADP, or the combination of ADP and epinephrine. Thus, the inhibitory effects of ethanol on platelet responses in the presence of PGI2 were very similar to its inhibitory effects in the absence of PGI2, when platelets were stimulated with lower concentrations of collagen or thrombin. Ethanol did not appear to exert its inhibitory effects by increasing cyclic AMP above basal levels and the additional inhibitory effects of ethanol in the presence of PGI2 did not appear to be brought about by further increases in platelet cyclic AMP levels.

Aggregation of Cat Platelets in Vitro

1970 ◽  
Vol 23 (03) ◽  
pp. 601-620 ◽  
Author(s):  
Th. B Tschopp
Keyword(s):  
Adenosine Monophosphate ◽  
Blood Collection ◽  
Base Line ◽  
Reversible Aggregation ◽  
Low Concentrations ◽  
Irreversible Aggregation ◽  
High Concentrations ◽  
Two Phases ◽  
Improved Technique

SummaryAggregation of cat platelets in the citrated plasma is examined by means of Born’s absorptiometer. A marked tendency of the platelets of this species to spontaneous aggregation necessitated first of all the development of an improved technique of blood collection.A hypothesis according to which 5-HT is released from the platelets, explains the absence of oscillations on the base line of the absorptiometer, the absence of platelet swelling, when ADP is added, and the effect of stirring on the aggregation curves in cat PRP. The average volume of cat platelets amounts to 10.46 μ3 when directly fixed in the blood, when fixed from PRP to 12.17 μ3, when fixed from stirred PRP to 13.51 μ3.In low concentrations (0.3-2 μM) ADP produce reversible aggregation; in narrowly restricted, individually dissimilar mean concentrations irreversible aggregation in two phases and in high concentrations, irreversible aggregation in one phase. Like ADP serotonin produces 2 phase irreversible aggregation in concentrations of 3-10 μM, but unlike ADP, the aggregation velocity decreases again with high 5-HT concentrations (>100 μM). Adrenaline does not produce aggregation and it is likely that adenosine and adenosine monophosphate inhibit the aggregation by serotonin but not by ADP. Species differences in the aggregation of human, rabbit and cat platelets are discussed.

Thrombin Generation Measured Ex Vivo Following Microvasculor Injury Is Increased in SLE Patients with Antiphospholipid-protein Antibodies

1997 ◽  
Vol 78 (04) ◽  
pp. 1173-1177 ◽  
Author(s):  
Jacek Musiał ◽  
Jakub Swadźba ◽  
Miłosz Jankowski ◽  
Marek Grzywacz ◽  
Stanisława Bazan-Socha ◽  
...  
Keyword(s):  
Lupus Erythematosus ◽  
Thrombin Generation ◽  
Ex Vivo ◽  
Skin Incision ◽  
Anticardiolipin Antibodies ◽  
Small Blood Vessel ◽  
Anionic Phospholipids ◽  
Increased Risk ◽  
High Concentrations

SummaryAntiphospholipid-protein antibodies (APA) include lupus-type anticoagulant (LA) and antibodies recognizing complexes of anionic phospholipids (e.g. cardiolipin) and proteins (e.g. prothrombin and (β2-glycoprotein I). The presence of APA is associated with an increased risk of both arterial and venous thrombosis. However, the pathogenic mechanism leading to thrombosis in patients with APA remains unclear. We studied 32 patients with systemic lupus erythematosus (SLE) who were divided into two groups depending on the presence (n = 19) or absence (n = 13) of APA. Healthy volunteers (n = 12) matched by age and sex served as controls. In all subjects LA and IgG class anticardiolipin antibodies (ACA) were determined. Thrombin generation was monitored ex vivo measuring fibrinopeptide A (FPA) and prothrombin fragment F1 + 2 (F1 + 2) in blood emerging from a skin microvasculature injury, collected at 30 second intervals. In subjects with antiphospholipid antibodies mean FPA and F1 + 2 concentrations were signiF1cantly higher at most blood sampling times than in controls. In some SLE patients with APA the process of thrombin generation was clearly disturbed and very high concentrations of F1brinopeptide A were detected already in the F1rst samples collected. Two minutes after skin incision SLE patients without APA produced slightly more FPA, but not F1 + 2, as compared to healthy subjects. Mathematical model applied to analyze the thrombin generation kinetics revealed that APA patients generated signiF1cantly greater amounts of thrombin than healthy controls (p = 0.02 for either marker). In contrast, in the same patients generation of thrombin in recalciF1ed plasma in vitro was delayed pointing to the role of endothelium in the phenomenon studied. In summary, these data show for the F1rst time that in SLE patients with antiphospholipid-protein antibodies thrombin generation after small blood vessel injury is markedly increased. Enhanced thrombin generation might explain thrombotic tendency observed in these patients.

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