RNF219 attenuates global mRNA decay through inhibition of CCR4-NOT complex-mediated deadenylation

The CCR4-NOT complex acts as a central player in the control of mRNA turnover and mediates accelerated mRNA degradation upon HDAC inhibition. Here, we explored acetylation-induced changes in the composition of the CCR4-NOT complex by purification of the endogenously tagged scaffold subunit NOT1 and identified RNF219 as an acetylation-regulated cofactor. We demonstrate that RNF219 is an active RING-type E3 ligase which stably associates with CCR4-NOT via NOT9 through a short linear motif (SLiM) embedded within the C-terminal low-complexity region of RNF219. By using a reconstituted six-subunit human CCR4-NOT complex, we demonstrate that RNF219 inhibits deadenylation through the direct interaction of the α-helical SLiM with the NOT9 module. Transcriptome-wide mRNA half-life measurements reveal that RNF219 attenuates global mRNA turnover in cells, with differential requirement of its RING domain. Our results establish RNF219 as an inhibitor of CCR4-NOT-mediated deadenylation, whose loss upon HDAC inhibition contributes to accelerated mRNA turnover

Characterization of the behavior of carotenoids from pitanga (Eugenia uniflora) and buriti (Mauritia flexuosa) during microemulsion production and in a dynamic gastrointestinal system

Uncommon tropical fruits are emerging as raw-material for new food products with health benefits. This work aimed at formulating and processing microemulsions from pitanga (Eugenia uniflora) and buriti (Mauritia flexuosa) fruits, since they are very rich in carotenoids (particularly lycopene and -carotene), in order to encapsulate and increase carotenoids bioaccessibility. Pitanga and buriti microemulsions were produced by applying a direct processing (high-speed homogenization at 15,000 rpm and ultrasound with 20 kHz probe at 40% amplitude) of the whole pulp together with surfactant (Tween 80 or Whey Protein Isolate at 2%) and corn oil (5%). All treatments (HSHUS for 04, 40, 44, 48 minmin) applied were able to increase the amount of carotenoid released. However, the processing also decreased the total amount of carotenoids in the whole pulp of studied fruits. The impact of processing during microemulsion production was not severe. The overall data suggest that the presence of surfactant and oil during processing may protect the carotenoids in fruits and microemulsions. Final recovery of total carotenoids, after passing the samples through a dynamic gastrointestinal system that simulates the human digestion, was higher for microemulsions than for whole pulps. High losses of total carotenoids in buriti and -carotene and lycopene in pitanga occurred during jejunum and ileum phases. The present work confirms that it is possible to increase -carotene and lycopene bioaccessibility from fruits by directly processing microemulsions (p<0.01).This work was supported by the São Paulo Research Foundation—FAPESP through research funding [Grant #2015/15507-9] and Ph.D. scholarship for Paulo Berni [Grant #2014/15119-6] and a Research Internships Abroad (BEPE) support [Grant #2016/13355-0]. The author Ana C. Pinheiro is recipient of a fellowship from the Portuguese Foundation for Science and Technology (FCT) [Grant SFRH/BPD/101181/2014]info:eu-repo/semantics/publishedVersio

Spectral detection of stress-related pigments in salt-lake succulent halophytic shrubs

The spectral detection of vegetation pigment concentrations has a high potential value, but it is still underdeveloped, especially for pigments other than chlorophylls. In this study, the seasonal pigment dynamics of two Tecticornia species (samphires; halophytic shrubs) from north-western Australia were correlated with spectral indices that best document the pigment changes over time. Pigment dynamics were assessed by analysing betacyanin, chlorophyll and carotenoid concentrations at plant level and by measuring reflectance at contrasting seasonal dates. Plant reflectance was used to define a new reflectance index that was most sensitive to the seasonal shifts in Tecticornia pigment concentrations. The two Tecticornia species turned from green to red-pinkish for the period March–August 2012 when betacyanins increased almost nine times in both species. Chlorophyll levels showed the opposite pattern to that of betacyanins, whereas carotenoid levels were relatively stable. Normalised difference indices correlated well with betacyanin (r = 0.805, using bands at 600 and 620 nm) and chlorophyll (r = 0.809, using bands at 737 and 726 nm). Using knowledge of chlorophyll concentrations slightly improved the ability of the spectral index to predict betacyanin concentration (r = 0.822 at bands 606 and 620 nm, in the case of chemically determined chlorophyll, r = 0.809 when using remotely sensed chlorophyll). Our results suggest that this new spectral index can reliably detect changes in betacyanin concentrations in vegetation, with potential applications in ecological studies and environmental impact monitoring.Fil: Marchesini, Victoria Angela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Matemática Aplicada de San Luis ; Argentina. University of Western Australia; AustraliaFil: Guerschman, Juan P.. Csiro Land and Water; AustraliaFil: Schweiggert, Ralf M.. Universidad de Hohenheim; AlemaniaFil: Colmer, Timothy D.. University of Western Australia; AustraliaFil: Veneklaas, Erik J.. University of Western Australia; Australi

A Biosensor of Src Family Kinase Conformation by Exposable Tetracysteine Useful for Cell-Based Screening

We developed a new approach to distinguish distinct protein conformations in live cells. The method, exposable tetracysteine (XTC), involved placing an engineered tetracysteine motif into a target protein that has conditional access to biarsenical dye binding by conformational state. XTC was used to distinguish open and closed regulatory conformations of Src family kinases. Substituting just four residues with cysteines in the conserved SH2 domain of three Src-family kinases (c-Src, Lck, Lyn) enabled open and closed conformations to be monitored on the basis of binding differences to biarsenical dyes FlAsH or ReAsH. Fusion of the kinases with a fluorescent protein tracked the kinase presence, and the XTC approach enabled simultaneous assessment of regulatory state. The c-Src XTC biosensor was applied in a boutique screen of kinase inhibitors, which revealed six compounds to induce conformational closure. The XTC approach demonstrates new potential for assays targeting conformational changes in key proteins in disease and biology

High pressure processing assisted enzymatic hydrolysis - An innovative approach for the reduction of soy immunoreactivity

Soybean (Glycinemax (L.)MERR.) is recognized as a potent food allergen causing one of the most frequent food allergies worldwide. The effect of high pressure processing (HPP) prior to and during enzymatic hydrolysis using the enzyme preparation Flavourzyme® on the degree of hydrolysis (DH), molecular weight distribution (SDS-PAGE) and β-conglycinin (Glym5) immune reactivity of soy protein isolate (SPI)was studied. Enzymatic hydrolysis was carried out at atmospheric pressure (0.1MPa) and HPP (100–600MPa) at 50 °C for 15 min. Pressures higher than 300 MPa enhanced the degradation of Gly m5, which was confirmed by SDS-PAGE and LC-MS/MS analyses. The immunoreactivity of the samples was assessed by invitro sandwich ELISA using mouse monoclonal anti-Gly m5 antibodies. Depending on the antibody tested, the residual immunoreactivity was completely inhibited or significantly impaired up to 99.5% applying HPP during hydrolysis at 400 and 500 MPa. By means of principal component analysis, the beany and green off-flavors characteristic for unprocessed SPI could be reduced by pressure enhanced hydrolysis at 400–500 MPa. The resulting hydrolysates possessed improved protein solubility, foaming activities and oil-binding capacities, which were improved by 45%, 66%, and 210%, respectively. HPP prior to and during enzymatic hydrolysis at 400–500MPa constitutes an innovative approach for the production of low-allergen food ingredients that combine good taste and enhanced functional properties. Industrial relevance: Food allergy has emerged in the last years as the incidence and prevalence are rising dramatically. Up to now, enzymatic hydrolysis is the only feasible method to mitigate soy allergy. However, the major drawback associated with enzymatic hydrolysis is the incomplete destruction of allergenic epitopes and the formation of a strong bitter taste. This research activity demonstrates that high pressure assisted enzymatic hydrolysis using the enzyme preparation Flavourzyme effectively reduces the immunoreactivity of soy proteins. Degree of hydrolysis analysis, SDS-PAGE, mass spectrometry as well as sandwich ELISAwithmousemonoclonalanti-Glym5antibodieshave been applied to analyze the destruction of allergenic proteins as well as to determine the residual immunoreactivity. This study provides preliminary evidence that this innovative combination process of high pressure and enzymatic hydrolysis has great potential to produce tasty low-allergen soy-based food ingredients with good physicochemical properties, i.e. protein solubility and foam ability

Carotenoids are more bioavailable from papaya than from tomato and carrot in humans: a randomised cross-over study

Carrot, tomato and papaya represent important dietary sources of b-carotene and lycopene. The main objective of the present study was to compare the bioavailability of carotenoids from these food sources in healthy human subjects. A total of sixteen participants were recruited for a randomised cross-over study. Test meals containing raw carrots, tomatoes and papayas were adjusted to deliver an equal amount of b-carotene and lycopene. For the evaluation of bioavailability, TAG-rich lipoprotein (TRL) fractions containing newly absorbed carotenoids were analysed over 9·5 h after test meal consumption. The bioavailability of b-carotene from papayas was approximately three times higher than that from carrots and tomatoes, whereas differences in the bioavailability of b-carotene from carrots and tomatoes were insignificant. Retinyl esters appeared in the TRL fractions at a significantly higher concentration after the consumption of the papaya test meal. Similarly, lycopene was approximately 2·6 times more bioavailable from papayas than from tomatoes. Furthermore, the bioavailability of b-cryptoxanthin from papayas was shown to be 2·9 and 2·3 times higher than that of the other papaya carotenoids b-carotene and lycopene, respectively. The morphology of chromoplasts and the physical deposition form of carotenoids were hypothesised to play a major role in the differences observed in the bioavailability of carotenoids from the foods investigated. Particularly, the liquid-crystalline deposition of b-carotene and the storage of lycopene in very small crystalloids in papayas were found to be associated with their high bioavailability. In conclusion, papaya was shown to provide highly bioavailable b-carotene, b-cryptoxanthin and lycopene and may represent a readily available dietary source of provitamin A for reducing the incidence of vitamin A deficiencies in many subtropical and tropical developing countries.German Academic Exchange Service/[]//AlemaniaUCR::Vicerrectoría de Docencia::Ciencias Agroalimentarias::Facultad de Ciencias Agroalimentarias::Escuela de Tecnología de AlimentosUCR::Vicerrectoría de Docencia::Salud::Facultad de Medicina::Escuela de Medicin