Thesis (M.S.)--West Virginia University, 2002. / Title from document title page. Document formatted into pages; contains ix, 67 p. : ill. Includes abstract. Includes bibliographical references (p. 63-67).

Diss. (sammanfattning) Umeå : Umeå universitet, 2009. / Härtill 4 uppsatser.

Thesis (Ph. D.)--University of Washington, 2000. / Vita. Includes bibliographical references (leaves 97-104).

Diss. (sammanfattning) Umeå : Umeå universitet, 2010. / Härtill 4 uppsatser.

O objetivo do estudo foi estimar a biodisponibilidade de duas fontes de cobre: orgânica (cobre metionina) e inorgânica (sulfato de cobre) na dieta de cordeiros. O experimento foi conduzindo na FZEA USP de Pirassununga utilizando 40 cordeiros da raça Merino X Texel, que foram distribuídos aleatoriamente em cinco grupos, e submetidos a cinco tratamentos, totalizando oito animais por tratamento: Tratamento 0: Dieta controle sem adição de Cu; Tratamento 1: 10 mg de Cu/Kg de MS na forma de sulfato de Cu; Tratamento 2: 30g de Cu/Kg de MS na forma de sulfato de Cu; Tratamento 3: 10 mg de cu/kg de MS na forma de cobre metionina; Tratamento 4: 30 mg de cu/kg de MS na forma de cobre metionina. Foram feitas biópsias do fígado dos animais no tempo zero para análise de cobre e colhidas amostras de sangue nos dias 0, 28, 56 e 84 dias para determinação de Cu sérico, atividade de ceruloplasmina e enzimas de função hepática. Ao final do experimento, os animais foram abatidos para colheita de amostras de fígado, músculo e rim, para determinação dos teores de Cu e da enzima superóxido dismutase (SOD). Nos últimos dez dias do experimento foi realizado um balanço metabólico de cobre. A biodisponibilidade foi calculada pela técnica \"slope ratio\", utilizando como parâmetros a concentração de cobre no fígado. Não houve diferença (P>0,05) no desempenho dos animais (peso vivo e ganho de peso) entre os tratamentos. A concentração sérica de AST e ALT permaneceu abaixo dos níveis de intoxicação em todos os tratamentos, durante todo o período. A atividade da ceruloplasmina não diferiu entre os tratamentos (P>0,05). O teor de cobre no soro, na biópsia do fígado e no músculo não foi diferente (P>0,05) entre os tratamentos. Entretanto, a concentração do mineral no fígado dos animais suplementados (284,28 mg/kg) foi maior (P<0,05), quando comparados ao grupo controle (168,01 mg/kg), assim como o Cu-met 30 mg/kg (341,29 mg/kg) foi superior (P<0,05) ao de 10mg/kg MS (263,02 mg/kg). A atividade da SOD nos animais suplementados (µmol/mg prot foi superior à do grupo controle. Nos rins o teor de cobre foi superior nos animais que receberam 30mg/kg de MS de Cu-met (6,65 mg/kg) em relação aos que receberam 10 mg/kg de MS da mesma fonte (3,86 mg/kg). A absorção e a retenção aparentes do cobre foram maiores para a fonte inorgânica, comparada com a orgânica. A biodisponibilidade do cobre determinada pela concentração de cobre no fígado, utilizando a técnica do \"slope ratio\", considerando o CuSO4 como padrão (100%), apresentou disponibilidade de 150,64% para o Cu-met. / The study was conducted to estimate the relative bioavailability of two sources of supplemental copper: organic (copper methionine) and inorganic (copper sulfate) in the diet of lambs, by analyzing the concentration of copper and enzymes in the liver and metabolic balance calculation, using 40 lambs breed Merino X Texel, which was fed three concentrations of copper (basal + two additions) in two sources, which were randomly allotted to five groups, and subjected to five treatments: treatment 0: control (diet without addition of Cu); treatment 1: (diet with 10 mg Cu/Kg DM of CuSO4); Treatment 2: (diet with 30 g Cu/Kg DM of CuSO4); Treatment 3: (diet with 10 mg Cu/kg DM of copper methionine; Treatment 4: (diet with 30 mg cu/kg DM of copper methionine). Liver biopsies were made on 0 d. Blood samples were taken via the jugular vein on 0, 28, 56 and 84 d to determine serum Cu and serum ceruloplasmin and liver transaminases (AST, ALT) concentrations. The animals were slaughtered and samples of liver, kidney and muscle were taken for the determination of the levels of Cu and superoxide dismutase activity. In the last ten days of the experiment a metabolic balance of copper was conducted. The bioavailability was calculated by the \"slope ratio\" technique, using the concentration of copper in the liver as parameter. There was no difference (P >0.05) on animal performance (live weight and weight gain) among treatments. The serum AST and ALT levels remained below poisoning in all treatments during the period. The ceruloplasmin activity did not differ between treatments (P>0.05). The copper content in biopsy, serum and muscle was not different (P>0.05) between treatments. However, the mineral concentration in the liver of animals fed (284.28 mg/kg) was higher (P <0.05) when compared to the control group (168.01 mg/kg ) and 30 Cu -met mg/kg (341.29 mg/kg) was higher (P <0.05) at 10mg/kg MS (263.02 mg/kg). The SOD activity in the supplemented animals (mmol/mg prot) was superior to the control group. Copper in Kidneys was higher in animals that received 30mg/kg MS meth-Cu (6.65mg/kg) compared those receiving 10 mg/kg DM from the same source (3.86 mg/kg). Apparent absorption and retention of copper were higher for inorganic source, compared with the organic. The bioavailability determined by the concentration of copper in the copper liver, using the technique of \"slope ratio\", considering CuSO4 as standard ( 100% ) presented availability of 150.64 % for Cu-met.

<p>The flower is debatably the most complex of the plant organs, composed of far more tissues than any other plant organ system, and, as such, the molecular mechanisms that govern tissue specification and development have only just begun to be explored. One tissue that has seen little research is the stigma. The stigma is the apical-most part of the gynoecium and is designed to trap pollen grains on specialized cells called stigma papillae and provide the means for them to germinate. Using a forward genetic screen, many mutants which exhibit defects in stigma development were identified. The identification of the genes with the causative mutations will uncover new genes involved in stigma development which can be linked to previously discovered genes to build a more comprehensive gene regulatory network of stigma specification. Over the course of the screen, a new mutant, <i>lily</i>, was identified which has open buds throughout most of flower development. This valuable genetic tool allows microscopy and chemical applications at younger stages than emasculation allows. Here, <i>lily</i> was used to show the importance of reactive oxygen species in stigma specification and identity maintenance. In addition to specification, the morphological differentiation of stigma papillae was investigated. Using reverse and chemical genetics, live-imaging, and morphometrics, it was found that stigma papillae grow via an anisotropic diffuse growth mechanism. Collectively, these findings constitute a substantial breaking of ground for stigma research, providing a solid foundation for future investigation.</p>

Cu/Zn Superoxide Dismutase (SOD1), is a ubiquitous antioxidant enzyme with several emerging roles outside of its canonical function. SOD1 is also emerging in central roles in cancer and neurodegenerative pathologies. Little is known about SOD1 regulation, particularly at a post-translational level. Post-translational modifications (PTMs) play an important role in enabling proteins to rapidly respond to their environment. Therefore, identifying specific PTMs involved in protein regulation represents a powerful opportunity to interfere with any associated pathologies. This work employs proteomics to identify mechanisms of post-translation regulation on cell survival signaling proteins. We focused on SOD1, which protects cells from oxidative stress. We found that acylation of K122 on SOD1, while not impacting SOD1 catalytic activity, suppressed the ability of SOD1 to inhibit mitochondrial metabolism at respiratory complex I. We found that deacylase depletion increased K122 acylation on SOD1, which blocked suppression of respiration in a K122-dependent manner. In addition, we found that acyl-mimicking mutations at K122 decreased SOD1 accumulation in mitochondria, initially hinting that SOD1 may inhibit respiration directly within the intermembrane space (IMS). However, surprisingly, we found that forcing the K122 acyl mutants into the mitochondria with an IMS-targeting tag did not recover their ability to suppress respiration. Moreover, we found that suppressing or boosting respiration levels toggled SOD1 in or out of the mitochondria, respectively. These findings place SOD1-mediated inhibition of respiration upstream of its mitochondrial localization. Interestingly, we also found that K122 acyl mutants were sufficient to prevent mitochondrial accumulation of the G93A SOD1 clinical mutant. We observed increased autophagic activity in G93A expressing cells compared to WT or G93A/K122-acyl mimic double mutants, and found that this double mutant was just as prone to aggregate as G93A SOD1—suggesting that SOD1 aggregation is more toxic when in the mitochondria. We observed increased protein turnover rates in cells expressing SOD1 G93A, in support of increased autophagy. Lastly, deletion-rescue experiments show that a respiration-defective mutant of SOD1 is also impaired in its ability to rescue cells from toxicity caused by SOD1 deletion. Together, these data suggest a new interplay between SOD1 acylation, metabolic regulation, SOD1 aggregate toxicity, and SOD1-mediated cell survival.

Copper is an essential cofactor of two mitochondrial enzymes: cytochrome c oxidase (COX) and the mitochondrial localized fraction of Cu-Zn superoxide dismutase (Sod1p). Copper incorporation into these enzymes is facilitated by a growing number of metallochaperone proteins. Here we describe two novel copper chaperones of COX, Cmc1 and Cmc2. In Saccharomyces cerevisiae, both Cmc1 and Cmc2 localize to the mitochondrial inner membrane facing the intermembrane space. Cmc1 and Cmc2 are essential for full expression of COX and cellular respiration, contain a twin Cx9C domain, and are conserved from yeast to humans. Additionally, the presence or absence of these proteins not only determines full assembly of functional COX but also affects metallation of Sod1 suggesting these proteins might play a role on co-modulation of copper transfer to COX and Sod1. CMC1 overexpression does not rescue the respiratory defect of cmc2 mutants or vise versa. However, Cmc2 physically interacts with Cmc1 and the absence of Cmc2 induces a 5-fold increase in Cmc1 accumulation in the mitochondrial membranes. We conclude that Cmc1 and Cmc2 have cooperative but non-overlapping functions in cytochrome c oxidase biogenesis.

No description available.

Amyotrophic lateral sclerosis (ALS) is the most common motor neuron disease and is characterized by progressive paralysis leading to death, typically, within 3-5 years of the onset of symptoms. The majority of ALS cases are sporadic with no known causative agent; however, 5-10% of ALS cases are genetically inherited and termed familial ALS (fALS). Approximately, 15-20% of these fALS cases have been linked to mutations in the gene encoding human Cu/Zn superoxide dismutase (hSOD). To date, over 140 hSOD mutations have been discovered. The mechanisms by which mutant hSOD confers toxicity in fALS patients are still unknown. However, there is growing evidence that ALS is a type of protein conformational disease whereby cell damage or death is caused by the accumulation of protein aggregates in the cell. It is hypothesized that mutations destabilise hSOD and increase its propensity to aggregate. There is some controversy as to which hSOD species contributes to aggregation. Many believe that only apo or mismetallated forms of hSOD are able to aggregate. Due to the abundance of fully metallated or holo hSOD in the cell, we hypothesize that holo hSOD can also lead to aggregation. Holo dimer interface mutants A4S, A4T and I113T as well as G41D were found to be destabilized compared to holo pseudo wildtype (pWT) while zinc binding mutant H80R was shown to form fragments via an unknown mechanism. Holo dimer interface mutants A4S and A4T were also shown to have an increased propensity to aggregate compared to pWT, which correlates to their decreased stability as well a short disease durations.