Ligand-stimulated internalization of a Dictyostelium discoideum G protein-coupled cAMP receptor

The social amoeba, Dictyostelium discoideum, undergoes a remarkable starvation-induced program of development that transforms a population of unicellular amoebae into a fruiting body composed of resistant spores suspended on a stalk. During this development, secreted cAMP drives chemotaxis of the amoebae, leading to their aggregation, and subsequent differentiation and morphogenesis. Four sequentially expressed G protein-coupled receptors (GPCRs) for cAMP play critical roles in this process. The first of these, cAR1, is essential for aggregation as it mediates chemotaxis as well as the propagation of secreted cAMP waves throughout aggregating populations. Ligand-induced internalization has been shown to regulate a variety of GPCRs. However, little was known at the outset of this study about the role of internalization in the regulation of cAR1 function or, for that matter, in developmental systems in general. For this study, cAMP-induced cAR1 internalization was assessed by measuring (1) the reduction of cell surface binding sites for [ 3H]cAMP and (2) the redistribution of YFP-tagged receptors to the cell's interior, cAMP was found to induce little or no loss of ligand binding (LLB) in vegetative cells. However, the ability to induce LLB increased progressively over the initial 6 hrs of development, reaching ∼70% in cells undergoing aggregation. Despite these reductions in surface binding, detectable cAR1-YFP redistribution could be induced by cAMP only after the cells reached the mound stage (10 hrs) and was found to occur naturally by the ensuing slug stage (18 hrs). Site-directed substitution of a cluster of 5 serines in the receptor's cytoplasmic tail that was previously shown to be the principal site of cAMP-induced cAR1 phosphorylation impaired both LLB and receptor redistribution and furthermore resulted in mound-stage developmental arrest, suggesting that phosphorylation of cAR1 is a prerequisite for its internalization and that cAR1 internalization is required for post-aggregative development. To assess the involvement of clathrin mediated endocytosis, Dictyostelium cells lacking the clathrin light chain gene (clc-) or either of two dynamin genes were examined and found to be defective in LLB and, in the case of clc- cells, also cAR1 redistribution and turnover. Furthermore, cAR1 overexpression in clc- cells (like the serine mutant in wild-type cells) promoted developmental arrest in mounds. The mound-arrest phenotype was also recapitulated in a wild-type background by the specific expression of cAR1 in prestalk cells (but not prespore cells), suggesting that development depends critically on internalization and clearance of cAR1 from these cells. Persistent cAR1 expression following aggregation was found to be associated with aberrant expression of prestalk and prespore genes, which may adversely affect development in the prestalk cell lineage. The PI3 kinase-TORC2 signal transduction pathway, known to be important for Dictyostelium chemotaxis and internalization of yeast pheromone receptors, was examined using chemical inhibitors and null cells and found to be necessary for cAR1 internalization. In conclusion, cAR1 was shown to be similar to other GPCRs in that its internalization depends on phosphorylation of cytoplasmic domain serines, utilizes clathrin and dynamin, and involves the TORC2 complex. In addition, the findings presented here that cAR1 internalization is both developmentally regulated and required for normal development represent a novel regulatory paradigm that might pertain to other GPCRs known to play important roles in the development of humans and other metazoans. ^

Evolutionary conservation of sequence elements controlling cytoplasmic polyadenylylation.

Cytoplasmic polyadenylylation is an evolutionarily conserved mechanism involved in the translational activation of a set of maternal messenger RNAs (mRNAs) during early development. In this report, we show by interspecies injections that Xenopus and mouse use the same regulatory sequences to control cytoplasmic poly(A) addition during meiotic maturation. Similarly, Xenopus and Drosophila embryos exploit functionally conserved signals to regulate polyadenylylation during early post-fertilization development. These experiments demonstrate that the sequence elements that govern cytoplasmic polyadenylylation, and hence one form of translational activation, function across species. We infer that the requisite regulatory sequence elements, and likely the trans-acting components with which they interact, have been conserved since the divergence of vertebrates and arthropods.

Researches on the insect metamorphosis ...

"From Transactions of the Royal Society of South Australia, vol. xlvi., 1922."

A history of Christian thought /

Vol. 1 originally issued 1943 with imprint: Philadelphia, United Lutheran Publication House.

Resoluciones aprobadas en el Trigésimo Quinto Período de Sesiones de la CEPAL

Resolución 676(XXXV) Calendario de conferencias de la CEPAL para el período 2015-2016 .-- Resolución 677(XXXV) Conferencia Regional sobre la Mujer de América Latina y el Caribe .-- Resolución 678(XXXV) Conferencia Estadística de las Américas de la Comisión Económica para América Latina y el Caribe .-- Resolución 679(XXXV) Respaldo a la labor del Instituto Latinoamericano y del Caribe de Planificación Económica y Social (ILPES) .-- Resolución 680(XXXV) Comité de Desarrollo y Cooperación del Caribe .-- Resolución 681(XXXV) Conferencia Regional sobre Población y Desarrollo de América Latina y el Caribe .-- Resolución 682(XXXV) Establecimiento de la Conferencia Regional sobre Desarrollo Social de América Latina y el Caribe .-- Resolución 683(XXXV) Admisión de San Martín como miembro asociado de la Comisión Económica para América Latina y el Caribe .-- Resolución 684(XXXV) Prioridades y programa de trabajo de la Comisión Económica para América Latina y el Caribe para el bienio 2016-2017 .-- Resolución 685(XXXV) Actividades de la Comisión Económica para América Latina y el Caribe en relación con el seguimiento de los Objetivos de Desarrollo del Milenio y la aplicación de los resultados de las grandes conferencias y cumbres de las Naciones Unidas en las esferas económica y social y esferas conexas .-- Resolución 686(XXXV) Aplicación del Principio 10 de la Declaración de Río sobre el Medio Ambiente y el Desarrollo en América Latina y el Caribe .-- Resolución 687(XXXV) La dimensión regional de la agenda para el desarrollo después de 2015 .-- Resolución 688(XXXV) Cooperación Sur-Sur .-- Resolución 689(XXXV) Lugar del próximo período de sesiones .-- Resolución 690(XXXV) Resolución de Lima .-- Resolución 691(XXXV) Conferencia Ministerial sobre la Sociedad de la Información de América Latina y el Caribe.

Resolutions Adopted At The Thirty-Fifth Session Of The Economic Commission For Latin America And The Caribbean

Resolution 676(XXXV) ECLAC calendar of conferences for the period 2015-2016 .-- Resolution 677(XXXV) Regional Conference on Women in Latin America and the Caribbean .-- Resolution 678(XXXV) Statistical Conference of the Americas of the Economic Commission for Latin America and the Caribbean .-- Resolution 679(XXXV) Support for the work of the Latin American and Caribbean Institute for Economic and Social Planning .-- Resolution 680(XXXV) Caribbean Development and Cooperation Committee .-- Resolution 681(XXXV) Regional Conference on Population and Development in Latin America and the Caribbean .-- Resolution 682(XXXV) Establishment of the Regional Conference on Social Development in Latin America and the Caribbean .-- Resolution 683(XXXV) Admission of Sint Maarten as an associate member of the Economic Commission for Latin America and the Caribbean .-- Resolution 684(XXXV) Programme of work and priorities of the Economic Commission for Latin America and the Caribbean for the 2016-2017 biennium .-- Resolution 685(XXXV) Activities of the Economic Commission for Latin America and the Caribbean in relation to follow-up to the Millennium Development Goals and implementation of the outcomes of the major United Nations conferences and summits in the economic, social and related fields .-- Resolution 686(XXXV) Application of Principle 10 of the Rio Declaration on Environment and Development in Latin America and the Caribbean .-- Resolution 687(XXXV) The regional dimension of the post-2015 development agenda .-- Resolution 688(XXXV) South-South cooperation .-- resolution 689(XXXV) Place of the next session .-- Resolution 690(XXXV) Lima resolution .-- Resolution 691(XXXV) Ministerial Conference on the Information Society in Latin America and the Caribbean.

Résolutions Adoptées À La Trente-Cinquième Session De La CEPALC

Résolution 676(XXXV) Calendrier de conférences de la CEPALC pour la période 2015-2016 .-- Résolution 677(XXXV) Conférence régionale sur les femmes de l’Amérique latine et des Caraïbes .-- Résolution 678(XXXV) Conférence statistique des Amériques de la Commission économique pour l’Amérique latine et les Caraïbes .-- Résolution 679(XXXV) Appui aux travaux de l’Institut latino-américain et des Caraïbes de planification économique et sociale (ILPES) .-- Résolution 680(XXXV) Comité de développement et de coopération des Caraïbes .-- Résolution 681(XXXV) Conférence régionale sur la population et le développement de l’Amérique latine et des Caraïbes .-- Résolution 682(XXXV) Création de la Conférence régionale sur le développement social de l’Amérique latine et des Caraïbes .-- Résolution 683(XXXV) Admission de Saint-Martin en qualité d’état membre associé de la Commission économique pour l’Amérique latine et les Caraïbes .-- Résolution 684(XXXV) Priorités et programme de travail de la Commission économique pour l’Amérique latine et les Caraïbes pour la période biennale 2016-2017 .-- Résolution 685(XXXV) Activités de la Commission économique pour l’Amérique latine et les Caraïbes dans le cadre du suivi des objectifs du Millénaire pour le développement et l’application des résultats des grandes conférences et des sommets des Nations Unies en matière économique et sociale et dans les domaines connexes .-- Résolution 686(XXXV) Application du Principe 10 de la Déclaration de Rio sur l’environnement et le développement en Amérique latine et dans les Caraïbes .-- Résolution 687(XXXV) La dimension régionale du programme de développement pour l’après 2015 .-- Résolution 688(XXXV) Coopération Sud-Sud .-- Résolution 689(XXXV) Lieu de la prochaine session .-- Résolution 690(XXXV) Résolution de Lima .-- Résolution 691(XXXV) Conférence ministérielle sur la société de l’information de l’Amérique latine et des Caraïbes.

The politics of the new Germany

The Politics of the New Germany takes a new approach to understanding politics in the post-unification Federal Republic. Assuming only elementary knowledge, it focuses on debates and issues in order to help students understand both the workings of Germany's key institutions and some of the key policy challenges facing German politicians. Written in a straightforward style by four experts, each of the chapters draws on a rich variety of real-world examples. Packed with boxed summaries of key points, a guide to further reading and a range of seminar questions for discussion at the end of each chapter, this book highlights both the challenges and opportunities facing policy-makers in such areas as foreign affairs, economic policy, immigration, identity politics and institutional reforms. The book also takes a bird's-eye view of the big debates that define German politics over time, regardless of which party happens to be in power. It pinpoints three key themes that have characterised German politics over the last sixty years; reconciliation, consensus and transformation. Table of Contents: Introduction 1. Germany and the Burden of History 2. Germany’s Post-War Development, 1945-1989 3. Towards German Unity? 4. A Blockaded System of Government? 5. The Party System and Electoral Behaviour: The Path to Stable Instability? 6. Economic Management: The End of the German Model? 7. Citizenship and Demographics: A Country of Immigration? 8. The Reform of the Welfare State? 9. Germany and the European Union: A European Germany or a German Europe? 10. Foreign and Security Policy: A New Role for the Twenty-First Century? 11. Conclusion

A political economy of the ethnic chinese catering industry

The present political climate in which the ideals of entrepreneurship and self-help are strongly encouraged has drawn attention to those ethnic minorities noted for their entrepreneurial activity. Since the Chinese appear to be an exemplary case in point, this thesis focusses upon the historical material conditions which have led to the formation of a Chinese 'business* community in Britain, both past and present As such, it rejects the theories of cultural determinism which characterise most studies of the Chinese. For rather than representing the endurance of cultural norms, the existence of the contemporary Chinese 'niche' of ethnically exclusive firms in the catering industry is due to the conjunction of a number of historical processes. The first is the imperialist expansion into China of Britain's capitalist empire during the nineteenth century which established a relationship of dependency upon the interests of British capital by colonial Chinese labour. The second is the post war development of the catering industry and its demand for cheap labour as administered by the British state together with the contemporaneous development of the agricultural economy of colonial Hong Kong. Far from representing a source of material benefit to all, the ethnic Chinese 'niche' in catering is highly exploitative and merely underlines the racial oppression of Chinese in Britain. Attempts to promote business interests within the ethnic community therefore serve merely to entrench the structures of oppression.

Data compilation on the biological response to ocean acidification: environmental and experimental context of data sets and related literature

The exponential growth of studies on the biological response to ocean acidification over the last few decades has generated a large amount of data. To facilitate data comparison, a data compilation hosted at the data publisher PANGAEA was initiated in 2008 and is updated on a regular basis (doi:10.1594/PANGAEA.149999). By January 2015, a total of 581 data sets (over 4 000 000 data points) from 539 papers had been archived. Here we present the developments of this data compilation five years since its first description by Nisumaa et al. (2010). Most of study sites from which data archived are still in the Northern Hemisphere and the number of archived data from studies from the Southern Hemisphere and polar oceans are still relatively low. Data from 60 studies that investigated the response of a mix of organisms or natural communities were all added after 2010, indicating a welcomed shift from the study of individual organisms to communities and ecosystems. The initial imbalance of considerably more data archived on calcification and primary production than on other processes has improved. There is also a clear tendency towards more data archived from multifactorial studies after 2010. For easier and more effective access to ocean acidification data, the ocean acidification community is strongly encouraged to contribute to the data archiving effort, and help develop standard vocabularies describing the variables and define best practices for archiving ocean acidification data.

Location and ages of terrestrial peatlands located on continental shelves and in coastal sediments

This synthesis dataset contains records of freshwater peat and lake sediments from continental shelves and coastal areas. Information included is site location (when available), thickness and description of terrestrial sediments as well as underlying and overlying sediments, dates (when available), and references.

Seawater carbonate chemistry and biological processes during experiments with postlarvae of barnacle of Semibalanus balanoides and Elminius modestus, 2010

Ocean acidification and global warming are occurring concomitantly, yet few studies have investigated how organisms will respond to increases in both temperature and CO2. Intertidal microcosms were used to examine growth, shell mineralogy and survival of two intertidal barnacle post-larvae, Semibalanus balanoides and Elminius modestus, at two temperatures (14 and 19°C) and two CO2 concentrations (380 and 1,000 ppm), fed with a mixed diatom-flagellate diet at 15,000 cells ml-1 with flow rate of 10 ml-1 min-1. Control growth rates, using operculum diameter, were 14 ± 8 µm day-1 and 6 ± 2 µm day-1 for S. balanoides and E. modestus, respectively. Subtle, but significant decreases in E. modestus growth rate were observed in high CO2 but there were no impacts on shell calcium content and survival by either elevated temperature or CO2. S. balanoides exhibited no clear alterations in growth rate but did show a large reduction in shell calcium content and survival under elevated temperature and CO2. These results suggest that a decrease by 0.4 pH(NBS) units alone would not be sufficient to directly impact the survival of barnacles during the first month post-settlement. However, in conjunction with a 4-5°C increase in temperature, it appears that significant changes to the biology of these organisms will ensue.