Estudos experimentais e clínicos amparam a participação do estresse oxidativo na progressão da doença renal na doença renal policística autossômica dominante (DRPAD). A administração do agente antioxidante N-acetilcisteína (NAC), por sua vez, apresenta efeitos benéficos em vários modelos animais de injúria renal. Neste estudo, utilizamos um camundongo cístico gerado por meio do cruzamento de uma linhagem portadora de um alelo floxed Pkd1 com outra que expressa nestin-Cre para avaliar os efeitos da NAC sobre um modelo ortólogo à DRPAD humana. O tratamento de longo prazo com NAC foi iniciado na concepção, nascimento, desmame ou oito semanas de idade, de modo a permitir a avaliação de seus efeitos em diferentes fases da vida. Nossas análises revelaram que a administração de NAC reduziu o nível de substâncias reativas com ácido tiobarbitúrico e aumentou o de glutationa nos rins de camundongos císticos tratados com NAC desde a concepção (Ci-NAC-Conc) comparados a animais císticos não tratados (Ci-Co). A excreção urinária de óxido nítrico também foi maior em camundongos císticos tratados com NAC. Animais Ci-NAC-Conc apresentaram ureia sérica, número de cistos renais, índice cístico e fibrose intersticial renal mais baixos que os camundongos Ci-Co. Animais Ci-NAC-Conc apresentaram, além disso, fração de ejeção e fração de encurtamento de ventrículo esquerdo maiores que camundongos Ci-Co, assim como menor fibrose cardíaca. O tratamento com NAC iniciado na concepção aumentou a sobrevida dos animais císticos. Notavelmente, o peso corpóreo mostrou-se significantemente menor em camundongos Ci-NAC-Conc que nos animais Ci-Co em todas as idades avaliadas, uma diferença não observada entre animais não císticos tratados e não tratados com NAC. Ainda é incerto se todas as ações observadas da NAC são causadas por suas propriedades antioxidantes. Esses resultados apóiam efeitos benéficos de tratamento precoce com NAC em camundongos císticos deficientes em Pkd1, determinados pela melhora de seus fenótipos renal, cardíaco e sistêmico. Nossos achados também revelam uma redução não deletéria no crescimento corpóreo, induzida pela administração de longo prazo de NAC no background deficiente em Pkd1 avaliado. Nossos dados abrem uma linha de pesquisa significativa e provavelmente robusta para se intervir nos fenótipos renal, cardíaco e sistêmico da DRPAD / Oxidative stress has been postulated to participate in the progression of renal disease in autosomal dominant polycystic kidney disease (ADPKD). The antioxidant N-acetylcysteine (NAC), in turn, has been shown to determined beneficial effects on several animal models of renal injury. In the current study, a cystic mouse generated by breeding a Pkd1 floxed allele with a nestin Cre expressing line was used to evaluate the potential therapeutic effects of NAC on a model orthologous to human ADPKD. Long-term NAC treatment was initiated at conception, birth, weaning or 8 weeks of life, to allow the evaluation of its effects on different phases of life. Our analyses revealed that NAC decreased thiobarbituric acid reactive substances (TBARS) and increased glutathione levels in the kidneys of mice treated with NAC since conception (CY-NAC-Con) compared with non-treated cystic animals (CY-Ctl). Nitric oxide urinary excretion was also higher in NAC-treated cystic mice. These animals showed lower serum urea nitrogen (SUN), number of renal cysts, cystic index and renal interstitial fibrosis than CY-Ctl mice. CY-NAC-Con animals displayed, in addition, higher left ventricle ejection fraction and fractional shortening compared with CY-Ctl mice, as well as decreased cardiac fibrosis. NAC treatment started at conception increased the survival of cystic mice, demonstrating beneficial systemic effects. Interestingly, body weight was significantly lower in CY-NAC-Con than CY-Ctl mice at all evaluated times, a difference not observed between non-cystic animals treated and not treated with NAC Whether all observed NAC actions are caused by its antioxidant properties is yet not clear. These results support beneficial effects of early treatment with NAC on Pkd1-deficient cystic mice, by determining improvement in their renal, heart and systemic phenotypes. Our findings also reveal a non-deleterious reduction in body growth induced by long-term NAC administration in the evaluated Pkd1-deficient background. Our data open a likely significant and robust research track to intervene in renal, extra-renal and systemic ADPKD phenotypes

<p>Hemijska karakterizacija ekstrakata&nbsp; <em>T. pratense&nbsp;</em>L.&nbsp; određena je LC-MS-MS, a etarskih ulja GC-MS analizom, pri čemu je&nbsp; identifikovano vi&scaron;e&nbsp;bioaktivnih jedinjenja.&nbsp; Spektrofotometrijskim&nbsp;metodama ispitan je antioksidantni potencijal&nbsp;ekstrakata i etarskih ulja. Hepatoprotektivni&nbsp;efekat određen je&nbsp; na&nbsp; homogenatu i hemolizatu&nbsp;jetre laboratorijskih mi&scaron;eva.&nbsp; Budući da&nbsp; ova&nbsp;biljka ima visok sadržaj izoflavona, određena je&nbsp;<br />estrogena, antiestrogena aktivnost, kao i&nbsp;citotoksičnost ekstrakata. Antimikrobna&nbsp;<br />aktivnosta ekstrakata i etarskih ulja ispitana je&nbsp;na&nbsp; &scaron;est bakterijskih sojeva.&nbsp; Ekstrakti i etarska&nbsp;ulja su bili umereno aktivni u pogledu biolo&scaron;kih&nbsp;aktivnosti, osim u slučaju antimikrobne&nbsp;aktivnosti koju nije pokazao nijedan ispitivani&nbsp;uzorak.</p> / <p>The chemical characterization of&nbsp; <em>T.&nbsp; pratense</em> extracts was determined by LC-MS-MS, and the essential oils of the GC-MS analysis, wherein the&nbsp; various&nbsp; bioactive compounds were identified.&nbsp; Antioxidant potential of extracts and essential oils was tested&nbsp; by spectrophotometric methods.&nbsp; Hepatoprotective&nbsp; effect&nbsp; was determined&nbsp; in&nbsp; haemolysate and liver homogenate of&nbsp; laboratory&nbsp; mice.&nbsp; Estrogen, antiestrogen activity, as well&nbsp; as the cytotoxicity of the extracts were&nbsp; determined&nbsp; due to the high&nbsp;content of isoflavones.&nbsp; Antimicrobial activity of extracts and essential oils was&nbsp; investigatied&nbsp; on six bacterial strains. Essential oils and extracts were moderately active in terms of biological activity, except&nbsp; in the case of&nbsp;&nbsp; antimicrobial activity&nbsp; where none of the extracts were active against tested bacterial strains.</p>

L’objectif de ces travaux a été de développer des vernis acrylate photo-polymérisables à 100% d’extrait sec, destinés à protéger des pièces thermoplastiques en polycarbonate contre les endommagements mécaniques, en particulier contre la rayure. Les relations entre la composition, la structure et les propriétés de ces revêtements ont été explorées. Pour ce faire ont été étudiées la morphologie, les propriétés thermomécaniques ainsi que la résistance à la rayure des matériaux. Cette dernière a été évaluée par des tests de micro-scratch. La cinétique de formation des réseaux polymères a elle aussi été étudiée, par photo-DSC. Tous les matériaux étudiés présentent, en analyse thermomécanique dynamique, un module élevé à l’état caoutchoutique ainsi qu’une large relaxation mécanique. Un vernis pétro-sourcé à 100% d’extrait sec, qualifié de standard, a servi de point de départ à ces travaux. Il a tout d’abord été comparé à un vernis commercial solvanté photo-polymérisable, spécialement conçu pour la protection de pièces thermoplastiques. Celui-ci s’est avéré être plus efficace en termes de résistance à la rayure. Dans un deuxième temps, a été étudiée l’influence sur les propriétés du vernis standard pétro-sourcé d’un monomère multicyclique entrant dans sa composition. La modification de son pourcentage n’a permis d’apporter aucun bénéfice en termes de résistance à la rayure. Des nanoparticules de silice, d’alumine ou de zircone, disponibles sous forme de dispersion dans un monomère acrylate, ont ensuite été incorporées dans le vernis standard pétro-sourcé. Une organisation particulière de la nano-silice et de la nano-alumine au sein des matériaux étudiés a pu être observée par microscopie électronique en transmission. Il a été constaté que le taux de charge doit être élevé pour observer une augmentation du module élastique et une amélioration de la résistance à la rayure du vernis (≥15% massique dans le cas de la nano-silice). Par ailleurs, l’ajout de 5% massique de nano-silice dans le vernis n’a conduit à aucune modification de sa cinétique de photo-polymérisation. Enfin, une partie des composés acrylate pétro-sourcés du vernis standard a été substituée par des acrylates bio-sourcés disponibles industriellement. La cinétique de photo-polymérisation des deux types de vernis est similaire. Les conclusions de la comparaison entre les vernis bio-sourcés et le vernis standard pétro-sourcé en termes de résistance à la rayure dépendent de l’épaisseur des revêtements étudiés. L’ajout d’un composé monoacrylate bio-sourcé à la formulation des vernis tend à améliorer la recouvrance élastique des revêtements de faible épaisseur. L’acrylate d’isobornyle est en particulier intéressant, car il a aussi tendance à retarder l’apparition des craquelures au cours de la rayure. / The aim of this work was to develop 100% solids photo-polymerizable acrylate coatings, intended to protect thermoplastic pieces made of polycarbonate against mechanical damage, in particular scratches. The relationships between the composition, the structure and the properties of these coatings were examined. For this purpose the morphology, the thermomechanical properties and the scratch resistance of the materials, assessed by micro-scratch tests, were studied. The kinetics of the polymer network formation was also studied by photo-DSC experiments. All the materials feature a high elastic modulus and a broad mechanical relaxation in dynamic thermomechanical analysis. A 100% solids petro-based coating (standard) constituted the starting point of this work. First it was compared to a commercial photo-polymerizable coating containing solvents, specially designed to protect thermoplastic pieces. This commercial coating turned out to be more efficient against scratches. In a second time was studied the influence of the percentage of a multicyclic monomer, taking part in the composition of the standard petro-based coating, on the properties of the latter. The modification of its proportion does not bring any advantage concerning the scratch resistance. Silica, alumina and zirconia nanoparticles, dispersed in an acrylate monomer, were then incorporated in the standard petro-based coating. A particular organization of the silica or alumina nanoparticles in the materials could be observed by transmission electron microscopy. A high filler content is required to observe an increase in the elastic modulus and an enhancement of the scratch resistance of the coating (≥15% by weight for the nano-silica). Moreover, no change of the photo-polymerization kinetics was noticed through the addition of 5% by weight of nano-silica in the coating. Finally, some of the petro-based acrylate compounds of the standard coating were substituted by commercially available bio-based acrylate monomers. Both types of coatings feature similar polymerization kinetics. The conclusions concerning the comparison of the scratch resistance of the bio-based and standard petro-based coatings depend on their thickness. The incorporation of a bio-based monoacrylate compound in low thickness coatings tends to improve the elastic recovery. Isobornyl acrylate is particularly interesting since it also tends to delay the apparition of cracks along the scratch.

Ce mémoire de thèse s’intéresse aux phénomènes d’adhésion dans des composites à matrice thermoplastique obtenus par polymérisation radicalaire de mélanges réactifs. Après une courte introduction bibliographique sur les thématiques d’adhésion et d’adhérence, les propriétés générales des principaux éléments constitutifs des assemblages finaux sont étudiées séparément pour discuter de leur pertinence en vue d’une application composite. Une attention particulière est portée sur les systèmes réactifs acryliques à l’état liquide. L’étude se concentre ensuite sur les mécanismes réactionnels et l’évolution des propriétés des systèmes réactifs lors de la polymérisation. Ces problématiques sont de première importance pour anticiper les mécanismes gouvernant l’adhésion dans les composites obtenus mais aussi pour appréhender les potentielles problématiques à venir lors des étapes de mise en forme. Enfin, une étude est spécifiquement dédiée au cas de l’adhésion entre matrice acrylique et fibres de verre dans des composites à fibres de renfort continues. Les propriétés à l’interface verre/acrylique ont été évaluées à l’échelle microscopique dans des systèmes modèles et à l’échelle macroscopique dans des composites unidirectionnels, c'est à dire pouvant les défauts d’adhésion générés lors de la mise en forme. L’ensemble de ces résultats permet de se positionner quant à l’utilisation de solutions acryliques thermoplastiques pour des applications composites structuraux. / These PhD research works focus on adhesion phenomena involved in thermoplastic composites based on acrylic matrices obtained by free radical polymerization. After a short bibliographic section introducing some basics on adhesion phenomena and practical adhesion measurements, properties of elementary constituents are assessed to discuss their relevancy for composite applications. Special attention is paid to acrylic reactive systems and properties of acrylic resins at liquid state. Then, the reaction mechanisms involved in free radical polymerization are detailed. The changes in acrylic system properties during polymerization are investigated to anticipate further processing-related issues. At last, a study is dedicated to the assessment of interfacial adhesion between glass fiber and acrylic matrices in fiber reinforced composites. Interfacial properties are characterized at microscale in model systems and at macroscale in real-sized composites, i.e. integrating process-induced defects. From overall results, the relevancy of acrylic thermoplastic solutions for structural composite applications is discussed.

Le contexte environnemental actuel conduit les constructeurs automobiles à diminuer les émissions globales de CO2. Afin de répondre à cet objectif, plusieurs voies sont accessibles mais l’allègement de la structure du véhicule apparaît comme la solution la plus prometteuse grâce à la substitution des pièces métalliques par des matériaux composites et plus particulièrement des composites thermoplastiques à matrices acryliques. Cette étude s’est donc intéressée à développer et caractériser plusieurs formulations à base acrylique afin d’identifier les différents leviers (choix du monomère / condition de polymérisation) permettant d’atteindre une polymérisation rapide (< 3 à 5 min) adaptée aux hautes cadences de l’industrie automobile. Le moulage par transfert de résine (RTM) ayant été choisi comme procédé de mise en œuvre, une seconde étape de travail a été de caractériser l’évolution de la viscosité au cours de la polymérisation. En disposant des mesures cinétiques et rhéologiques, il a aussi été possible, par modèle inverse, de proposer un suivi in-situ de la polymérisation via la corrélation des données par des mesures diélectrométriques. Puis, dans une optique d’amélioration de la tenue chimique du PMMA, la synthèse d’un polymère réversible présentant alternativement une structure tridimensionnelle et une structure linéaire a été réalisée. Ainsi, grâce à la préparation d’un comonomère présentant des fonctions Diels-Alder, il a été possible d’obtenir un polymère ayant la capacité d’emprunter les propriétés de résistance chimique des réseaux thermodurcissables tout en conservant l’aptitude à la transformation des thermoplastiques. Enfin, une dernière étude s’est portée sur le renforcement du PMMA par mélange avec différents polymères. Ainsi, grâce à un choix judicieux de polymères présentant des caractéristiques physico-chimiques intéressantes, il a été possible d’améliorer significativement la tenue en température mais également la résistance au choc de la matrice acrylique développée. / Nowadays, polymer matrix composites are widely used for aerospace, automotive, railway and sport industries. For similar structural properties, these materials coul be very attractive since they could be 30 to 40% lighter than metallic counterparts. In the current context of environmental development issues, thermoplastic-based composites, (in our case acrylic matrix based one), can be considered as they can be easily recycled as opposed to thermoset-based ones. Furthermore, they could exhibit good mechanical properties, i.e. stiffness and impact resistance, enabling them to be relevant for many applications. Manufacturing structural composites requires to produce parts without defects having complex geometries. For this purpose Resin Transfer Molding (RTM) has been selected to process such composites. Indeed, it corresponds to a low temperature closed-mold process allowing for manufacturing complex continuous fiber-based-reinforced parts. However, it requires precursors with a very low viscosity (η < 1 Pa.s) to ensure a good impregnation of the dry preform. To be cost effective, fast reactive systems have also to be selected. Thermoplastic polymers which own a very high viscosity in molten state cannot be directly used. Our strategy is to design an acrylic-based reactive formulation exhibiting a very low initial viscosity, i.e. about 100 mPa.s and which can subsequently polymerizes via a free radical mechanism once the mold is filled and the preform fully impregnated. Therefore, our main objective is to optimize curing conditions (especially thermal initiator ratios and temperature) of RTM-compatible acrylic-based reactive formulations to lead to suitable composite parts with high conversion rate, low residual monomer content and relevant process cycles.

<p dir="ltr">The chemical constituents of terrestrial and atmospheric waters originate from biomass burning, fertilizer runoff, and anthropogenic activity, among other sources, and their multi-phase chemistry is complex. Sunlight plays an essential role in aquatic chemistry. Photosensitizers in terrestrial and atmospheric waters absorb light to form highly reactive species such as triplet excited carbon (³C*), hydroxyl radical (•OH), and singlet oxygen (¹O₂), driving the photochemical transformations of dissolved organic matter (DOM) in the aqueous phase. Of note, these reactive species transform DOM compounds that do not undergo direct photolysis. DOM frequently undergoes a change in optical properties following photochemical processing, with implications for air quality, water quality, and human and animal health. The presence of inorganic minerals, such as the fertilizer compound struvite, in terrestrial or atmospheric waters introduces further complexity and impacts the photochemical processes that occur. Simplified proxy systems are created in the laboratory to simulate aquatic photochemical processes and evaluate the formation and/or photodegradation of photoproducts. These mixtures typically consist of a representative organic carbon (OC) compound and a photosensitizer, along with struvite or another inorganic mineral.</p>

Abstract : Monte Carlo simulations have proven to be very powerful techniques to study the radiolysis of water and the mechanisms underlying this radiolysis. Monte Carlo simulations particularly become important when there are no experimental results available in the literature due, for instance, to the difficulty of performing such experiments. This thesis presents a study of the radiolysis of water irradiated by different types of radiation and at various temperatures, employing Monte Carlo simulations. The first part of the thesis uses Monte Carlo simulations to elucidate the mechanisms involved in the self-radiolysis of tritiated water and to examine the importance of the effects of higher “linear energy transfer” (LET) by comparing [[superscript 3]H [beta][superscript -] radiations (mean initial energy of ~5.7 keV) with [superscript 60]Co [gamma]-rays (~1 MeV electrons). Our simulations showed that, for [superscript 3]H [beta][superscript -], we observe lower radical and higher molecular yields than in γ-radiolysis. These differences in yields are consistent with differences in the nonhomogeneous distribution of primary transient species in the two cases. Overall, our results corroborate well with previously reported work, and support a picture of [superscript 3]H [beta][superscript -] radiolysis mainly driven by the chemical action of “short tracks” of high local LET. This same trend in yields of radical and molecular products was also found under acidic conditions as well as in the aerated Fricke dosimeter. One of our main findings was that the measured Fricke yield G(Fe[superscript 3+]) could be best reproduced if a single, mean “equivalent” electron energy of ~7.8 keV were used to mimic the energy deposition by the tritium [beta][superscript -] particles (rather than the commonly used mean of ~5.7 keV), in full agreement with a previous recommendation of ICRU Report 17. The second part of this thesis investigates the radiolysis of the ceric-cerous sulfate dosimeter at elevated temperatures. In this radiolysis, H[superscript •] (or HO[subscript 2][superscript •] in the presence of oxygen) and H[subscript 2]O[subscript 2] produced by the radiolytic decomposition of water both reduce Ce[superscript 4+] ions to Ce[superscript 3+] ions, while [superscript •]OH radicals oxidize the Ce[superscript 3+] present back to Ce[superscript 4+]. Our simulations showed that the net Ce[superscript 3+] yield decreases almost linearly with increasing temperature up to ~250 °C, in excellent agreement with experiment. Above 250 °C, our model predicts that G(Ce[superscript 3+]) drops markedly with temperature until, instead of Ce[superscript 4+] reduction, Ce[superscript 3+] oxidation is observed. This drop is shown to result from the occurrence of the reaction of H[superscript •] atoms with water in the homogeneous chemical stage.//Résumé : La méthodologie de simulation Monte-Carlo s’est révélée être une très puissante technique dans l’étude des mécanismes de la radiolyse de l’eau. En particulier, la simulation Monte-Carlo se rend même plus importante quand les résultats expérimentaux ne sont pas disponibles, notamment dû aux difficultés techniques. Le mémoire actuel représente une étude sur la radiolyse de l’eau irradiée par différents rayonnements à différentes températures, en utilisant la simulation Monte-Carlo. Dans la première partie de ce mémoire, on examine les mécanismes d’auto-radiolyse de l’eau tritiée ainsi que l’importance de l’effet de « transfert linéaire d'énergie » (TLE) en comparant les électrons [béta][indice supérieur -] de [indice supérieur 3]H avec les rayons [béta][indice supérieur -] de [indice supérieur 60]Co. Nos simulations montrent que, pour les rayons [béta][indice supérieur -] de [indice supérieur 3]H, on observe moins de production de radicaux libres et plus de produits moléculaires. Ces différences de rendement sont en accord avec les différences de distribution non-homogène des espèces primaires transitoires dans les deux cas. En résumé, nos résultats corroborent bien avec les travaux publiés précédemment et donnent une perspective de la radiolyse [béta][indice supérieur -] de [indice [supérieur 3]H qui est en majorité contrôlée par l’action chimique de « trajectoires courtes » de TLE local élevé. La même tendance pour la production des radicaux libres et des produits moléculaires a été trouvée en milieu acide ainsi que pour le dosimètre aéré de Fricke. Un de nos résultats principaux montre que le rendement G(Fe[indice supérieur 3+]) du dosimètre de Fricke peut être mieux reproduit si une seule énergie électronique moyenne « équivalente » de ~7.8 keV est utilisée pour mimer la déposition d’énergie par les particules [béta][indice supérieur -] du tritium (au lieu de la valeur moyenne de ~5.7 keV qui est utilisée fréquemment). Ceci est en complet accord avec une recommandation du rapport 17 de l’ICRU. La deuxième partie de ce mémoire concerne la radiolyse du dosimètre au sulfate cérique-céreux à températures élevées. Lors de cette radiolyse, H[indice supérieur •] (ou HO[indice inférieur 2][indice supérieur •] en présence d’oxygène) et H[indice inférieur 2]O[indice inférieur 2] produits par la décomposition radiolytique de l’eau réduisent les ions cériques Ce[indice supérieur 4+] en ions céreux Ce[indice supérieur 3+], tandis que les radicaux [indice supérieur •]OH oxydent Ce[indice supérieur 3+] en Ce[indice supérieur 4+]. Nos simulations montrent que le rendement G (Ce[indice supérieur 3+]) décroît quasi linéairement avec la température entre 25 et 250 ° C, en excellent accord avec l’expérience . Au-dessus de 250 °C, notre modèle prédit une diminution marquée de G (Ce[indice supérieur 3+]) jusqu’à ce qu’on l’observe, au lieu d’une réduction de Ce[indice supérieur 4+], une oxydation de Ce[indice supérieur 3+]. Nous montrons que cette diminution est due à l’intervention de la réaction des atomes H[indice supérieur •] avec l’eau en milieu homogène.

In the budding yeast Saccharomyces cerevisiae, the evolutionarily conserved Target of Rapamycin (TOR) signaling network regulates cell growth in accordance with nutrient and stress conditions. In this work, I present evidence that the TOR complex 1 (TORC1)-interacting proteins Nnk1, Fmp48, Mks1, and Sch9 link TOR to various facets of nitrogen metabolism and mitochondrial function. The Nnk1 kinase controlled nitrogen catabolite repression-sensitive gene expression via Ure2 and Gln3, and physically interacted with the NAD+-linked glutamate dehydrogenase Gdh2 that catalyzes deamination of glutamate to alpha-ketoglutarate and ammonia. In turn, Gdh2 modulated rapamycin sensitivity, was phosphorylated in Nnk1 immune complexes in vitro, and was relocalized to a discrete cytoplasmic focus in response to NNK1 overexpression or respiratory growth. The Fmp48 kinase regulated respiratory function and mitochondrial morphology, while Mks1 linked TORC1 to the mitochondria-to-nucleus retrograde signaling pathway. The Sch9 kinase appeared to act as both an upstream regulator and downstream sensor of mitochondrial function. Loss of Sch9 conferred a respiratory growth defect, a defect in mitochondrial DNA transmission, lower mitochondrial membrane potential, and decreased levels of reactive oxygen species. Conversely, loss of mitochondrial DNA caused loss of Sch9 enrichment at the vacuolar membrane, loss of Sch9 phospho-isoforms, and small cell size suggestive of reduced Sch9 activity. Sch9 also exhibited dynamic relocalization in response to stress, including enrichment at mitochondria under conditions that have previously been shown to induce apoptosis in yeast. Taken together, this work reveals intimate connections between TORC1, nitrogen metabolism, and mitochondrial function, and has implications for the role of TOR in regulating aging, cancer, and other human diseases.

In the budding yeast Saccharomyces cerevisiae, the evolutionarily conserved Target of Rapamycin (TOR) signaling network regulates cell growth in accordance with nutrient and stress conditions. In this work, I present evidence that the TOR complex 1 (TORC1)-interacting proteins Nnk1, Fmp48, Mks1, and Sch9 link TOR to various facets of nitrogen metabolism and mitochondrial function. The Nnk1 kinase controlled nitrogen catabolite repression-sensitive gene expression via Ure2 and Gln3, and physically interacted with the NAD+-linked glutamate dehydrogenase Gdh2 that catalyzes deamination of glutamate to alpha-ketoglutarate and ammonia. In turn, Gdh2 modulated rapamycin sensitivity, was phosphorylated in Nnk1 immune complexes in vitro, and was relocalized to a discrete cytoplasmic focus in response to NNK1 overexpression or respiratory growth. The Fmp48 kinase regulated respiratory function and mitochondrial morphology, while Mks1 linked TORC1 to the mitochondria-to-nucleus retrograde signaling pathway. The Sch9 kinase appeared to act as both an upstream regulator and downstream sensor of mitochondrial function. Loss of Sch9 conferred a respiratory growth defect, a defect in mitochondrial DNA transmission, lower mitochondrial membrane potential, and decreased levels of reactive oxygen species. Conversely, loss of mitochondrial DNA caused loss of Sch9 enrichment at the vacuolar membrane, loss of Sch9 phospho-isoforms, and small cell size suggestive of reduced Sch9 activity. Sch9 also exhibited dynamic relocalization in response to stress, including enrichment at mitochondria under conditions that have previously been shown to induce apoptosis in yeast. Taken together, this work reveals intimate connections between TORC1, nitrogen metabolism, and mitochondrial function, and has implications for the role of TOR in regulating aging, cancer, and other human diseases.

No description available.