Seed maturation is an important process that is evolutionarily advantageous, allowing for seed dispersal and germination under favourable growth conditions. The B3-domain transcription factor FUSCA3 (FUS3) is a master regulator of seed maturation and controls developmental phase transitions through hormonal regulation in Arabidopsis thaliana. The aim of this study was to determine the post-translational regulation of FUS3 during embryonic and vegetative development. Here, FUS3 was found to interact with the E3 ubiquitin ligase ABI3-INTERACTING PROTEIN2 (AIP2) in yeast two-hybrid, in vitro, and in planta assays. Analysis of transcriptional and translational reporters also showed overlapping spatial and temporal expression patterns of AIP2 and FUS3. Furthermore, in vitro FUS3 degradation was delayed in aip2-1 mutant and increased FUS3-GFP levels were observed during mid-embryogenesis in aip2-1. Finally, double transgenic plants overexpressing AIP2 and FUS3 showed reduced FUS3 levels and reversion of the gain-of-function FUS3 phenotypes back to WT. Together, these results indicate that AIP2 is a negative regulator of FUS3.

This paper examines the synchronization of business cycles across the G7 countries during US recessions since the 1870s. Using a dynamic measure of correlations, results depend on the globalization period under consideration. During the 2007-2009 recession, business cycles co-movements increased to unprecedented levels. (author's abstract)

No description available.

The premise of this paper is that in a monetary production economy, policy decisions of the central bank, or more generally the 'monetary authority', set the tone not only for nominal interest rates but also for 'real' interest rates defined in the usual way. This is a different question than that of which institution(s) acquire the status of monetary authority at any particular stage of socioeconomic or technological development. Rather the suggestion is that the existence of some such social structure is a prerequisite if anything resembling capitalist monetary production is to be viable. The paper demonstrates that a coherent macroeconomic theory can be elaborated on this basis, including an explanation of economic growth, the business cycle, inflation, the functional distribution of income, the 'Keynesian' problem of the impact of demand growth on economic growth, endogenous money, cumulative causation, and endogenous technical change. (author's abstract) / Series: Working Papers Series "Growth and Employment in Europe: Sustainability and Competitiveness"

LNX1 belongs to a family of multi-PDZ domain containing RING-type E3 ligases. Several interactions have been mapped to its PDZ domains, but the role of each domain in LNX function has not yet been determined. To study individual PDZ domain function in the context of full length protein I generated point mutations in peptide binding sites of each of PDZ domain, and in a putative phosphoinositide binding site of LNX1 PDZ4. Peptide binding was successfully disrupted by an arginine or lysine to alanine mutation in the peptide binding cleft. A LNX1 PDZ4 mutant with lysine residues in a putative phosphoinositide binding site mutated to glutamate displayed decreased membrane localization. The impact of each PDZ mutation on cell morphology and substrate ubiquitination was also investigated. I identified a potential role for PDZ binding in auto-inhibition of RING function. Additionally, novel interactions between LNX1 and Frizzled family members were identified and characterized.

LNX1 belongs to a family of multi-PDZ domain containing RING-type E3 ligases. Several interactions have been mapped to its PDZ domains, but the role of each domain in LNX function has not yet been determined. To study individual PDZ domain function in the context of full length protein I generated point mutations in peptide binding sites of each of PDZ domain, and in a putative phosphoinositide binding site of LNX1 PDZ4. Peptide binding was successfully disrupted by an arginine or lysine to alanine mutation in the peptide binding cleft. A LNX1 PDZ4 mutant with lysine residues in a putative phosphoinositide binding site mutated to glutamate displayed decreased membrane localization. The impact of each PDZ mutation on cell morphology and substrate ubiquitination was also investigated. I identified a potential role for PDZ binding in auto-inhibition of RING function. Additionally, novel interactions between LNX1 and Frizzled family members were identified and characterized.

Thesis (D. Miss.)--Western Seminary, Portland, OR, 2007. / Abstract. Includes bibliographical references (leaves 197-201).

Thesis (D. Miss.)--Western Seminary, Portland, OR, 2007. / Abstract. Includes bibliographical references (leaves 197-201).

F-box only protein 7 (Fbxo7), a member of the F-box-only subfamily of FBPs, is a biologically and pathophysiologically important human protein that assumes many critical functions. The different functions of Fbxo7 depend on the formation of various multi-protein complexes. Possible interplay between different Fbxo7 functions further complicate the protein-protein interaction networks involved in Fbxo7 biology. Although significant progresses have been made to understand the functions, regulation, specificity, and protein interaction network of Fbxo7, a myriad of questions remain to be answered. The objectives of the work presented in this dissertation are to elucidate the molecular structures underlying the functions of Fbxo7 and the interaction with its protein partners, such as proteasome inhibitor PI31. The best known biological function of Fbxo7 is its role as the substrate-recognition subunit of the SCFFbxo7 (Skp1-Cul1-F-box protein) E3 ubiquitin ligase that catalyzes the ubiquitination of hepatoma up-regulated protein (HURP) and inhibitor of apoptosis protein (IAP). Fbxo7 also assumes various SCF-independent functions through interact with its protein partners that are not the substrates of the ubiquitin proteasome system, such as PI31, Cdk6, p27, PINK1 (PTEN-induced kinase 1), and Parkin. PI31 is a known proteasome regulator which was initially characterized as a proteasome inhibitor in vitro. The binding affinity between Fbxo7 and PI31 is very strong, and The Fbxo7-PI31 interaction is mediated by heterodimerization of the FP domains of the two proteins. This work is focus on study the protein structure of the two FP domains in Fbxo7 and PI3. Chapter 1 reviewed the F-box-only protein Fbxo7 biology including the function of Fbxo7 protein in ubiquitination proteasome pathway and some SCF-independent functions which are relate to human disease. Chapter 2 discussed the function of proteasome inhibitor PI31. With the many important biological functions, Fbxo7 is clearly an extraordinary important protein, but the lack of structural knowledge has hampered efforts to achieve a better understanding of Fbxo7 biology. In this work, we have determined the crystal structure of Fbxo7 FP domain (residues 181-335) and the crystal structure of the PI31 FP domain (residues 1-161) using a longer protein construct both at 2.0Å resolution. The Fbxo7 FP domain adopts an α/β-fold similar to that of the PI31 FP domain and the secondary structure elements of the two FP domains are comparable including the C-terminal helix, indicating that the two FP domains share the same overall global fold. However, an α helix and three β strands in the Fbxo7 are longer than their counterparts in the PI31 FP domain. The two FP domains also differ substantially in the length and conformation of the longest connecting loop. More importantly, structural differences between the two FP domains lead to drastically different modes of inter-domain protein–protein interaction: the PI31 FP domain utilizes either an α interface or β interface for homodimeric interaction, whereas the Fbxo7 FP domain utilizes an αβ interface. We have note that the inter-domain interaction of the Fbxo7 FP domain is much more extensive, featuring a larger contact surface area, better shape complementarity and more hydrophobic and hydrogen-bonding interactions. The results of this structural study provide critical insights into how Fbxo7 may dimerize (or multimerize) and interact with PI31 via the FP domain. Chapter 4 and Chapter 5 discussed the structure determinations, structure features and detail of protein-protein interactions of Fbxo7 and PI31 FP domains. Chapter 2 reviewed the corresponding fundamental biochemical techniques that been used in this study. Chapter 3 discussed protein structure determination by X-ray crystallography in structural biology studies. It was believed that the FP domains of Fbxo7 and PI31 mediate homodimerization and heterodimerization of the proteins and the FP domain is not present in other human proteins. In order to study the Fbxo7-PI31 heterodimerization protein-protein interactions, we performed modeling studies. Chapter 6 discussed the model building and binding studies. Based on the result of model building studies, we propose that an interaction between the two FP domains of Fbxo7 and PI31 should be mediated by a αβ interface using the α-helical surface of the Fbxo7 FP domain and the β-sheet surface of the PI31 FP domain. According to the result of pull down assay, the PI31 FP domain may complete with Skp1 for the binding with Fbxo7. It is possible that the formation of heterodimer between the Fbxo7 and PI31 mediate by FP domains may lead to the Fbxo7 dissociation from SCFFbxo7 complex which might reveal a new regulation mechanism.

Submitted by Nuzia Santos (nuzia@cpqrr.fiocruz.br) on 2013-01-24T17:51:01Z No. of bitstreams: 1 Alberto kazuo fuzikawa.pdf: 276958 bytes, checksum: 80d1525e280d315c92a5de15284db642 (MD5) / Made available in DSpace on 2013-01-24T17:51:01Z (GMT). No. of bitstreams: 1 Alberto kazuo fuzikawa.pdf: 276958 bytes, checksum: 80d1525e280d315c92a5de15284db642 (MD5) Previous issue date: 2007 / A apolipoproteína E (apoE) é um gene polimórfico, cujo produto protéico tem múltiplas funções no organismo humano, sobretudo no metabolismo lipídico. Tem sido investigado no contexto do envelhecimento, mas existem poucos estudos em populações bem definidas de idosos em países em desenvolvimento. Os objetivos deste trabalho foram (1) descrever a distribuição dos alelos comuns da apoE ( 2, 3, 4) e seus genótipos, numa população de 1.408 idosos (80,8% de todos os idosos com idade 60 anos) da linha de base da coorte de Bambuí, MG, Brasil, e estudar sua associação com variáveis demográficas (idade, sexo e cor da pele), (2) analisar a associação do polimorfismo da apoE com hipertensão arterial prevalente e variáveis biológicas (pressão arterial sistólica, diastólica, HDL colesterol, LDL colesterol e triglicérides), considerando potenciais fatores de confusão como idade, sexo, fatores de risco cardiovascular, ácido úrico e creatinina séricos. As amostras de DNA foram amplificadas pela reação em cadeia da polimerase e posteriormente digeridas com a enzima de restrição HhaI. O alelo 3 predominou (80,0%), seguido pelo 4 (13,5%) e 2 (6,5%). Todos os seis genótipos possíveis foram observados, sendo o genótipo 3 3 o mais freqüente (63,4%). Esta distribuição é semelhante à descrita em populações ocidentais. A análise de associação com variáveis demográficas foi feita por regressão logística multinomial, usando como variáveis dependentes os três alelos, seis genótipos e o número de alelos 4 por indivíduo. O sexo não se mostrou associado ao número de alelos 4, mas a cor de pele negra apresentou forte associação com a presença de dois alelos 4 (OR ajustado para idade e sexo = 7,38; IC 95% = 1,93-28,25), mostrando que Afro-brasileiros têm alta prevalência do alelo 4, como observado em populações negras Africanas. Nenhuma associação foi encontrada entre idade e o polimorfismo da apoE, sugerindo ausência de associação entre os genótipos e mortalidade nesta população. Hipertensão arterial, definida como pressão arterial sistólica 140 mmHg e / ou diastólica 90 mmHg, ou uso de medicação anti-hipertensiva, apresentou prevalência de 61,3%. Nas análises de associação com a pressão arterial e variáveis biológicas, a variável exploratória foi o genótipo da apoE, classificada em portadores de 2 ( 2 2 e 2 3) e portadores de 4 ( 4 4 e 3 4), tendo como grupo de referência os 3 3. Foram usados modelos de regressão linear múltipla para avaliar a associação com as variáveis biológicas e modelos de regressão de Poisson para estimar as razões de prevalência da hipertensão. Comparados aos homozigotos 3 3, os portadores de 2 tinham níveis séricos mais baixos de LDL colesterol (p < 0,001) e mais altos de triglicérides (p = 0,022), enquanto os portadores de 4 tinham níveis séricos mais altos de LDL colesterol (p = 0,036). Os portadores de 2 e de 4 não mostraram associação com a hipertensão arterial prevalente (razões de prevalência ajustados = 0,94, IC 95% = 0,83-1,07 e 0,98; IC 95% = 0,89-1,07, respectivamente), fornecendo evidência epidemiológica para a ausência de associação entre os genótipos da apoE com a hipertensão arterial prevalente entre idosos. / Apolipoprotein E (apoE) is a polymorphic gene, whose protein product is involved in several key roles in the human body, especially in lipid metabolism. It has been investigated in the context of aging, but there are few studies in well defined populations from developing countries. The objectives of this study were (1) to describe the allelic and genotypic distribution of the common apoE polymorphism ( 2, 3, 4) in a population of 1,408 elderly members (80.8% of all residents 60 years of age) from the baseline of a cohort from Bambuí city, Brazil, and to evaluate its association with demographic variables such as age, gender and skin color and (2) to analyze the association of the apoE polymorphism with prevalent arterial hypertension and biological variables (systolic blood pressure, diastolic blood pressure, HDL cholesterol, LDL cholesterol and triglycerides) in this population, considering potential confounding factors such as age, gender, cardiovascular risk factors, serum uric acid and creatinine. DNA samples were amplified by polymerase chain reaction and then digested with HhaI restriction enzyme. The 3 allele was predominant (80.0%), followed by 4 (13.5%) and 2 (6.5%). All six possible genotypes were observed, with 3 3 being the most frequent (63.4%). This distribution is similar to that described in other western populations. Analysis of association with demographic variables was done by multinomial logistic regression, using as dependent variables the three alleles, six genotypes and the number of 4 alleles per individual. Gender was not associated with the number of 4 alleles, but black skin color was strongly and independently associated with the presence of two 4 alleles (OR adjusted for age and gender = 7.38, 95% CI = 1.93-28.25), showing that African-Brazilians have a high prevalence of the 4 allele, as described in black African populations. No association was found between age and apoE polymorphism, suggesting an absence of association between apoE genotypes and mortality in this population. Arterial hypertension defined as systolic blood pressure 140 mmHg and / or diastolic blood pressure 90 mmHg, or use of antihypertensive medication, was present in 61.3% of participants. For the analysis of association with prevalent arterial hypertension and biological variables the exposure variable was the apoE genotype, divided as 2 carriers ( 2 2 and 2 3) and 4 carriers ( 4 4 and 3 4), having 3 homozygotes as the reference group. Multiple linear regression models were used to study association with biological variables and Poisson regression models to estimate prevalence ratios for hypertension. Compared to the 3 homozygotes, 2 carriers had lower levels of LDL cholesterol (p < 0.001) and higher levels of triglycerides (p = 0.022), while 4 carriers had higher levels of LDL cholesterol (p = 0.036). Neither the 2 or 4 carrier status was associated with hypertension (adjusted prevalence ratios = 0.94, 95% CI = 0.83-1.07 and 0.98, 95% CI = 0.89-1.07, respectively), providing epidemiologic evidence for the lack of association of apoE genotype with prevalent hypertension in old age.