Molecular cloning and sequencing of metallothionein in squamates: new insights into the evolution of the metallothionein genes in vertebrates.

Metallothioneins are cysteine-rich, metal-binding proteins ubiquitously expressed in living organisms. In the last past years, a plethora of vertebrate metallothionein sequences have become available, but so far there has been an almost absolute lack of data about sequences of metallothionein of non-avian diapsida. In the framework of the investigations on structural and functional properties of non-mammalian metallothioneins, we have cloned and sequenced the cDNAs encoding for metallothioneins of 10 squamate reptiles, belonging to 5 different infraorders. These sequences have been used to gain insight into the evolutionary history of metallothioneins in reptiles. Phylogenetic analysis shows that reptilian metallothionein phylogeny is inconsistent with the species phylogeny. Such findings allow us to hypothesize that the identified metallothionein in each squamate species used for this study might be considered a paralogous gene derived from more events of gene duplication and losses occurred during the diversification of the squamate species. Finally, through vertebrate metallothionein comparisons and phylogenetic analysis, we also add a novel contribution to the understanding of the evolution of metallothionein genes along the major vertebrate lineages.

Inferring evolution of fish proteins: the globin case study.

Because hemoglobins (Hbs) of all animal species have the same heme group, differences in their properties, including oxygen affinity, electrophoretic mobility, and pH sensitivity, must result from the interaction of the prosthetic group with specific amino acid residues in the primary structure. For this reason, fish globins have been the object of extensive studies in the past few years, not only for their structural characteristics but also because they offer the possibility to investigate the evolutionary history of Hbs in marine and freshwater species living in a large variety of environmental conditions. For such a purpose, phylogenetic analysis of globin sequences can be combined with knowledge of the phylogenetic relationships between species. In addition, Type I functional-divergence analysis is aimed toward predicting the amino acid residues that are more likely responsible for biochemical diversification of different Hb families. These residues, mapped on the three-dimensional Hb structure, can provide insights into functional and structural divergence.

Structure and expression of genes involved in transport and storage of iron in red-blooded and hemoglobin-less antarctic notothenioids.

Antarctic notothenioids are characterized by a drastic reduction of the hemoglobin content, a condition that reaches its extreme in icefish that, following a gene deletion event, are completely devoid of hemoglobin. To answer the question on what type of adaptive changes occurred in icefish to prevent accumulation of potentially dangerous ferrous iron, we investigated the genes of four proteins known to play a key role in iron metabolism. For this purpose, we cloned and sequenced the cDNAs encoding ceruloplasmin, transferrin, ferritin and divalent metal transporter 1. While the inferred amino acid sequences of transferrin from different Antarctic fish species showed a high level of similarity with the homologous proteins from other species, ceruloplasmin sequence featured amino acid substitutions affecting a copper binding site. Another peculiarity was the presence in subunit H of the icefish ferritin of the two sets of sites involved in iron oxidation and iron mineralization, which in mammals are located on two distinct ferritin subunits. Significant differences in the expression levels of the four genes were found between hemoglobinless and red-blooded notothenioids. An increased expression of ceruloplasmin mRNA in icefish was interpreted as a compensatory mechanism to prevent accumulation of ferrous iron in hemoglobinless fish. In icefish, the amounts of ferritin H-chain mRNA measured in liver, blood and head kidney were lower than in the same organs of the red-blooded fish. In the spleen of both fishes, the expression levels of ferritin H-chain were significantly lower than in the spleen of a "pink-blooded" notothenioid with an intermediate hemoglobin content. Finally, the amount of divalent metal transporter mRNA measured in the head-kidney was lower in the icefish than in the same organ of its red-blooded counterpart. These results indicate that the loss of hemoglobin in icefish is accompanied by remodulation of the iron metabolism.

Biogeography and adaptation of Notothenioid fish: hemoglobin function and globin-gene evolution.

The recognition of the important role of the polar habitats in global climate changes has awakened great interest in the evolutionary biology of polar organisms. They are exposed to strong environmental constraints, and it is important to understand how they have adapted to cope with these challenges and to what extent adaptations may be upset by current climate changes. We present an introductory overview of the evolution of the Antarctic fish fauna with emphasis on the dominant perciform sub-order Notothenioidei, as well as some specific comments on the biogeography of the three phyletically basal notothenioid families. The wealth of information on the ecology and biodiversity of the species inhabiting high-Antarctic and sub-Antarctic regions provides a necessary framework for better understanding the origin, evolution and adaptation of this unique group of fish. Notothenioidei offer opportunities for identification of the biochemical characters or the physiological traits responsible for thermal adaptation. The availability of phylogenetically related taxa in a wide range of latitudes has allowed to look into the molecular bases of environmentally driven phenotypic gain and loss of function. In the process of cold adaptation, the evolutionary trend of notothenioids has produced unique specialisations, including modification of hematological characteristics, e.g. decreased amounts and multiplicity of hemoglobins. The Antarctic family Channichthyidae (the notothenioid crown group) is devoid of hemoglobin. This loss is related to a single deletional event removing all globin genes with the exception of the inactive 3' end of adult alpha-globin. In reviewing hemoglobin structure, function and phylogeny, the evolution of the fish Root effect is analysed in detail. Adaptation of the oxygen-transport system in notothenioids seems to be based on evolutionary changes involving levels of biological organisation higher than the structure of hemoglobin.

Hemoglobin structure/function and globin-gene evolution in the Arctic fish Liparis tunicatus.

The importance of the Arctic, in contributing to the knowledge of the overall ensemble of adaptive processes influencing the evolution of marine organisms, calls for investigations on molecular adaptations in Arctic fish. Unlike the vast majority of Antarctic Notothenioidei, several Arctic species display high hemoglobin multiplicity. The blood of four species, the spotted wolffish of the family Anarhichadidae and three Gadidae, contains three functionally distinct major components. Similar to many Antarctic notothenioids, Arctic Liparis tunicatus (suborder Cottoidei, family Liparidae) has one major hemoglobin (Hb 1) accompanied by a minor component (Hb 2). This paper reports the structural and functional characterisation of Hb 1 of L. tunicatus. This hemoglobin shows low oxygen affinity, and pronounced Bohr and Root effects. The amino-acid sequence of the beta chain displays an unusual substitution in NA2 (beta2) at the phosphate-binding site, and the replacement of Val E11 (beta67) with Ile. Similar to some Antarctic fish Hbs, electron paramagnetic resonance spectra reveal the formation of a ferric penta-coordinated species even at physiological pH. The amino-acid sequences have also been used to gain insight into the evolutionary history of globins of polar fish. L. tunicatus globins appear close to the notothenioid clades as predicted by teleostean phylogenies. Close phylogenetic relationships between Cottoidei and Notothenioidei, together with their life style, seem to be the main factor driving the globin-sequence evolution.

The evolution of thermal adaptation in polar fish.

Given the unique thermal history of the Antarctic continent, fishes of dominant suborder Notothenioidei offer a remarkable opportunity to study the physiological and biochemical characters gained and, conversely, lost during their evolutionary history and to map this information on the species phylogenetic trees. The availability of phylogenetically related notothenioid taxa living in a wide range of latitudes (in the Antarctic, sub-Antarctic and temperate regions) allows to look into the molecular bases of environmentally driven gene birth and death. This evolutionary perspective has also been supported by comparison of some features of the hemoprotein devoted to the oxygen transport in fish species living in the other polar region, the Arctic. The Arctic and Antarctic marine ichthyofaunas differ by age and isolation. Fishes of the two polar regions have undergone different regional histories which have engineered the physiological diversities, so that Antarctic fish are much more stenothermal than Arctic ones. Understanding the mechanisms of phenotypic response to cold exposure in species living at different latitudes in polar habitats offers fundamental insights into environmental adaptations. This review aims at surveying the current knowledge of molecular structure, functional features, phylogeny and adaptations of the hemoglobin of fish thriving in the Antarctic, sub-Antarctic and Arctic regions (with some excursions in the temperate latitudes). Investigating the evolutionary adaptations of hemoglobins to these environments can provide new insights into adaptation currently studied merely in temperate organisms, and can shed light into the convergent processes that evolved in response to thermal adaptations.

Evolutionary fate of duplicate genes encoding aspartic proteinases. Nothepsin case study.

Gene duplication is considered an important evolutionary mechanism leading to new gene functions. According to the classical model, one gene copy arising from gene duplication retains the ancestral function, whilst the other becomes subject to directional selection for some novel functions. Hence, according to this model, long-term persistence of two paralogous genes is possible only with the acquisition of functional innovation. In the absence of neofunctionalization, one of the duplicate genes may be lost following accumulation of deleterious mutations, ultimately leading to the loss of function. Recently, new mechanisms have been proposed according to which both paralogs are maintained without apparent neofunctionalization. In this paper we describe the molecular evolution of the aspartic proteinase gene family, with particular regard for the nothepsin gene, a sex- and tissue-specific form of aspartic proteinase active in fish. The finding of nothepsin in a reptile is indicative of the presence of this gene in organisms other than fish. However, the failure to find any nothepsin-like gene in avian, murine and human genome suggests that the gene has been lost in certain lineages during evolution. At variance with piscine nothepsin expressed exclusively in female liver under the estrogens action, the reptilian counterpart lacks both tissue and sex specificity, as it is constitutively expressed in different tissues of male and female specimens. The expression of the nothepsin gene in fish and lizard is accompanied by the expression of a paralogous gene encoding for cathepsin D. Functional divergence analysis indicates that cathepsin D accumulated amino acid substitutions, whereas nothepsin retained most of the ancestral functions. Phylogenetic analysis shows a preponderance of replacement substitutions compared to silent substitutions in the branch leading to the cathepsin D clade, whilst nothepsin evolves under negative selection. To explain the loss of the nothepsin gene in certain lineages, we propose a model that takes into account the complementary degenerative mutations occurring in regulatory elements of the promoter regions of the two genes. According to this model, gene loss occurs whenever the two genes acquire the same expression pattern. The coexistence of cathepsin D and nothepsin is explained in terms of metabolic cooperation of the two enzymes.

Structural and functional studies of vertebrate metallothioneins: cross-talk between domains in the absence of physical contact.

In previous studies, we showed that the chemical and dynamic properties of fish and mouse MTs (metallothioneins) present a number of distinctive differences linked to their primary structures, and that phylogenetic relationships of mammal and fish MTs correlate with their three-dimensional structures. The different behaviours of MTs may also be linked to the interaction between their two domains. In the present study, we have compared the physicochemical properties of the isolated recombinant domains constituting Notothenia coriiceps and mouse MTs, and compared them with those of the corresponding whole MTs. NMR spectra of the separated domains of N. coriiceps are almost superimposable on those of the parent MT, suggesting an apparent lack of interaction between the two domains in the protein. However, certain dynamic and physicochemical features of the isolated domains are unlike those of the whole protein. In particular, the temperature-induced changes in the chiroptical properties, thiol reactivity of the Zn-MT domains and the Zn2+/Cd2+ rate of exchange are different for the two domains and with respect to the whole protein. Taken together, these results provide a strong argument in favour of the interaction of the two domains in the MT molecule, in spite of the elusive evidence provided by the structural analyses.

Solution structure of MT_nc, a novel metallothionein from the Antarctic fish Notothenia coriiceps.

The structure of [113Cd(7)]-metallothionein (MT_nc) of the Antarctic fish Notothenia coriiceps, the first three-dimensional structure of a fish metallothionein, was determined by homonuclear 1H NMR experiments and heteronuclear [1H, 113Cd]-correlation spectroscopy. MT_nc is composed of an N-terminal beta domain with 9 cysteines and 3 metal ions and a carboxy-terminal alpha-domain with 11 cysteines and 4 metal ions. The position of the ninth Cys of the alpha domain of MT_nc is different from the corresponding Cys of mammalian MTs. As a result, the last CXCC motif in the mammalian MT sequence becomes CXXXCC in the fish MT. This difference leads to a structural change of the alpha domain and, in turn, to a different charge distribution with respect to that observed in mammalian metallothioneins.

High affinity copper transport protein in the lizard Podarcis sicula: molecular cloning, functional characterization and expression in somatic tissues, follicular oocytes and eggs.

Copper (Cu) is an essential element required in many biological processes including cellular growth and development. The molecular mechanisms involved in copper homeostasis include proteins that play a role in Cu uptake. Genes encoding high affinity copper transporters (Ctr) have been identified in yeast, plant and mammalian cells. Analysis of copper and zinc content in growing ovarian follicles and ovulated eggs of the reptilian Podarcis sicula demonstrated that the levels of both metals rise during oocyte growth, reaching the maximum in ovulated eggs. By exploiting the remarkable evolutionary conservation of the primary structure of Ctr proteins, cDNA encoding a Ctr was isolated from the liver of the lizard P. sicula by reverse transcriptase PCR and RACE strategy by using primers designed based on consensus motifs present in mammalian Ctr. The predicted protein sequence contains three transmembrane domains and a putative hydrophilic extracellular amino-terminal domain. Besides complementing the respiratory deficiency of yeast cells defective in high affinity Cu transport, expression of lizard Ctr1(1) in Hek293 cells stimulates Cu uptake.Gene expression assessed by Northern blot hybridization of RNA from different tissues of P. sicula shows the highest levels of transcript in both intestine and liver. The profile of Ctr1 mRNA in growing ovarian follicles and eggs demonstrates that the transcript accumulates during the oocyte growth and reaches the highest levels in ovulated eggs. These results suggest that lizard Ctr1 protein may function in Cu acquisition in growing oocytes and eggs.

Fish and mammalian metallothioneins: a comparative study.

Structural studies show that fish and mammalian metallothioneins are endowed of distinctive features. In particular, the ninth cysteine residue present in the alpha domain of fish metallothionein is shifted of two positions with respect to the mammalian metallothionein, introducing a conformational modification in the protein structure. In addition, the fish metallothionein is less hydrophobic and more flexible than its mammalian counterpart. Our previous studies showed that the hydropathy of piscine and mammalian metallothioneins is significantly correlated with organismal temperature. In the present paper we have performed phylogenetic comparative analysis on metallothioneins of 24 species of fish and mammals. The results of such analysis failed to indicate that metallothionein hydropathy is an adaptive response to the thermal regime of the species. We concluded that metallothionein hydropathy is a trait that did not evolve in association with environmental changes.

Structure and function of the Gondwanian hemoglobin of Pseudaphritis urvillii, a primitive notothenioid fish of temperate latitudes.

The suborder Notothenioidei dominates the Antarctic ichthyofauna. The non-Antarctic monotypic family Pseudaphritidae is one of the most primitive families. The characterization of the oxygen-transport system of euryhaline Pseudaphritis urvillii is herewith reported. Similar to most Antarctic notothenioids, this temperate species has a single major hemoglobin (Hb 1, over 95% of the total). Hb 1 has strong Bohr and Root effects. It shows two very uncommon features in oxygen binding: At high pH values, the oxygen affinity is exceptionally high compared to other notothenioids, and subunit cooperativity is modulated by pH in an unusual way, namely the curve of the Hill coefficient is bell-shaped, with values approaching 1 at both extremes of pH. Molecular modeling, electronic absorption and resonance Raman spectra have been used to characterize the heme environment of Hb 1 in an attempt to explain these features, particularly in view of some potentially important nonconservative replacements found in the primary structure. Compared to human HbA, no major changes were found in the structure of the proximal cavity of the alpha-chain of Hb 1, although an altered distal histidyl and heme position was identified in the models of the beta-chain, possibly facilitated by a more open heme pocket due to reduced steric constraints on the vinyl substituent groups. This conformation may lead to the hemichrome form identified by spectroscopy in the Met state, which likely fulfils a potentially important physiological role.

Oestrogen-induced expression of a novel liver-specific aspartic proteinase in Danio rerio (zebrafish).

Aspartic proteinases are a group of endoproteolytic proteinases active at acidic pH and characterized by the presence of two aspartyl residues in the active site. They include related paralogous proteins such as cathepsin D, cathepsin E and pepsin. Although extensively investigated in mammals, aspartic proteinases have been less studied in other vertebrates. In a previous work, we cloned and sequenced a DNA complementary to RNA encoding an enzyme present in zebrafish liver. The sequence resulted to be homologous to a novel form of aspartic proteinase firstly described by us in Antarctic fish. In zebrafish, the gene encoding this enzyme is expressed only in the female liver, in contrast with cathepsin D that is expressed in all the tissues examined independently of the sex. For this reason we have termed the new enzyme liver-specific aspartic proteinase (LAP). Northern blot analyses indicate that LAP gene expression is under hormonal control. Indeed, in oestrogen-treated male fish, cathepsin D expression was not enhanced in the various tissues examined, but the LAP gene product appeared exclusively in the liver. Our results provide evidence for an oestrogen-induced expression of LAP gene in liver. We postulate that the sexual dimorphic expression of the LAP gene may be related to the reproductive process.

Gene amplification and cold adaptation of pepsin in Antarctic fish. A possible strategy for food digestion at low temperature.

Cold-adapted organisms have developed a number of adjustments at the molecular level to maintain metabolic functions at low temperatures. Among other features, they can produce enzymes characterized by a high turnover number or a high catalytic efficiency. The present work is aimed at investigating the process of food digestion at low temperature through the study of pepsins in Antarctic notothenioids. For such a purpose, we have cloned and sequenced three forms of pepsin A and a single form of gastricsin from the gastric mucosa of Trematomus bernacchii (rock cod). Phylogenetic analysis has suggested that the three pepsin A isotypes arose from two gene duplication events leading to the most ancestral pepsin A3 and to the most recent forms represented by pepsin A1 and pepsin A2. Molecular modeling has unraveled significant structural differences in these enzymes with respect to their mesophilic counterparts. Hydropathy and flexibility determined on the substrate-binding subsites of Antarctic and mesophilic pepsins have shown for pepsin A2 reduced hydropathy and increased flexibility at the level of the substrate cleft, features typical of cold-adapted enzymes. Northern blot analysis of RNA from rock cod gastric mucosa hybridized with molecular probes designed on specific regions of different pepsin forms has shown that rock cod pepsin genes are expressed at comparable levels. The present results suggest that the Antarctic rock cod adopted two different strategies to accomplish efficient protein digestion at low temperature. One mechanism is the gene duplication that increases enzyme production to compensate for the reduced kinetic efficiency, the other is the expression of a new enzyme provided with features typical of cold-adapted enzymes.

Adaptive evolution and functional divergence of pepsin gene family.

In vertebrates, a large proportion of genes is organized in gene families. Paralogous gene groups generated by gene duplication are related by homology, high degree of sequence identity and similar structural architecture of their products. Aspartic proteinases form a widely distributed protein superfamily including cathepsins, pepsins, renin and napsin. In the present study, the nucleotide sequences coding for various pepsins in 30 vertebrate species have been used to derive a gene phylogeny. Gene duplication and losses have been inferred from a reconciled tree, reconstructed by combining information from gene tree and species tree. Our findings based on the results of the relative rate ratio test and maximum likelihood analysis suggest that each round of gene duplication is characterized by adaptive evolution, although instances of evolution under positive selection have been found also long after divergence of gene families. The results of functional divergence analysis provided statistical evidence for shifted evolutionary rate after gene duplication.

Effect on Inhibition of Micromere Segregation on the Mitotic Pattern in the Sea Urchin Embryo: (micromeres/mitotic pattern/sea urchin).

Detergent treatment of sea urchin eggs at the mid 4-cell stage results in prevention of micromere segregation at the fourth cleavage. In these embryos not only the formation of the primary mesenchyme is suppressed, but synchrony of cell division, which is the rule during the first four cleavage cycles, continues for several cycles after the 16-cell stage while the typical mitotic phase wave that sets in after micromere segregation is abolished. These results support the hypothesis that micromeres act as coordinators of the mitotic activity of the embryo.

Intervenciones desde la psicología en el plan maestro de salud en la salud pública de San Luis, Argentina / Interventions from psychology in the master plan of health in public health of San Luis, Argentina / Intervenções da psicologia no plano diretor de saúde em saúde pública de San Luis, Argentina / Interventions de psychologie dans le plan directeur de la santé en santé publique de San Luis, Argentine

El objetivo de este estudio es abordar el Plan Maestro de Salud 2014-2025 de la provincia de San Luis, aprobado por Decreto del Poder Ejecutivo Nº 3991 MdeS-2014 y el cual integra la Ley N° 0813 - 2012 de Atención Primaria de la Salud, consideradas como políticas públicas, y analizar si la psicología podría desenvolver su quehacer profesional en el campo de la salud pública. Es, por lo tanto, una investigación en salud pública que se orientará en dos vértices: la epidemiología y las políticas públicas. La psicología de la salud debe indicar que sí posee un vasto campo disciplinar diverso, en el que la psicología clínica, la psicología social comunitaria y la psicología conductual se conectan indefectiblemente con la educación y la medicina, entre otras disciplinas. Tal como se presenta la salud pública, le es condición necesaria a la psicología estar al tanto de la estadística epidemiológica, o situación epidemiológica de la población a la cual quiere atender.

The objective of this study is to address the Master Health Plan 2014-2025 of the province of San Luis, which was approved by Executive Decree No. 3991 MdeS-2014,which integrates Law No. 0813 - 2012 of Primary Health Care, considered as public policies. This plan was considered as a public policy, and it analyzes whether Psychology could be a clinical specialty included in the field of public health. This work is, therefore, an investigation in public health with two orientations: epidemiology and public policies.The psychology of health must indicate that it does have a vast diverse disciplinary field, in which clinical psychology, community social psychology and behavioral psychology are inextricably linked with education and medicine, among other disciplines. As public health is presented, it is a necessary condition for psychology to be aware of the epidemiological statistics, or epidemiological situation of the population to which it wants to attend.

O objetivo deste estudo é abordar o Plano Diretor de Saúde 2014-2025 de San Luis, Argentina, aprovado pelo Decreto do Poder Executivo Nº 3991 MOH-2014, o qual integra a LeiN° 0813 - 2012 - de Atenção Primária da saúde, conceituadas como políticas públicas, consideradoscomo política pública, e analisar se a psicología poderia desenvolver o seu trabalho profissional no campo da saúde pública. Trata-se, portanto, de uma pesquisa em saúde pública que será orientada em dois vértices: epidemiologia e políticas públicas. A psicologia da saúde deve indicar que ela possui um vasto campo disciplinar diversificado, no qual a psicologia clínica, a psicologia social comunitária e a psicologia comportamental estão conectadas indefectivelmente com educação e medicina, entre outras disciplinas. Como a saúde pública é apresentada, é uma condição necessária para a psicologia estar ciente das estatísticas epidemiológicas, ou situação epidemiológica da população a qualquer participar. É, portanto, uma pesquisa em saúde pública que incide sobre dois vértices: epidemiologia e políticas públicas.

Cette étude a pour objectif l'analyse du Plan Directeur de Santé 2014-2025 de la province de San Luis, approuvé par le décret exécutif n ° 3991 MdeS-2014, qu'intègre la loi n ° 0813-2012 autour des soins de santé primaires, considérées comme politiques publiques, et il analyse si la psychologie peut être une spécialité clinique dans le domaine de la santé publique. Il s'agit donc d'une enquête en santé publique ayant deux orientations: l'épidémiologie et les politiques publiques. La psychologie de la santé doit indiquer qu'elle possède un vaste champ disciplinaire dans lequel la psychologie clinique, la psychologie sociale communautaire et la psychologie comportementale sont inextricablement liées avec l'éducation et la médecine, entre autres disciplines. Lorsque la santé publique est présentée, la psychologie doit nécessairement connaître les statistiques épidémiologiques où la situation épidémiologique de la population laquelle elle souhaite assister.

La Psicología Política en la Universidad Nacional de San Luis - Argentina / Political Psychology at National University of San Luis - Argentina / A Psicologia Política na Universidade Nacional de São Luis - Argentina / La Psychologie Politique de l'Université Nationale de San Luis - Argentine

El artículo propone un recorrido histórico institucional por las características de producción de conocimiento en Psicología Política en un espacio académico (Universidad Nacional de San Luis, Argentina), sus influencias, y su articulación con la formación profesional de grado en psicología. Desde la perspectiva propuesta, la Psicología Política reflexiona sobre las personas y analiza su dimensión subjetiva, recuperando su condición humana a partir de las mediaciones históricas micro y macro sociales que la atraviesan. La concepción y el ejercicio del poder; la distribución del conocimiento validado socialmente; el control social; los derechos humanos y las representaciones sociales de sectores de la realidad, la psicología económica, la participación política, salud mental y formación del psicólogo, son los ejes temáticos preponderantes.

The paper proposes an historical institutional journey through the knowledge production features in political psychology in an specific academic field (National University of San Luis, Argentina), its influences, and its articulation with the professional degree training in psychology. From this proposed point of view, political psychology reflects on people and analyzes their subjective dimension, recovering the human condition from micro and macro social historical mediations that cross it. Design and exercise of power; distribution of knowledge socially validated; social control; human rights and social representations of sectors of reality, economic psychology, political participation, mental health and training of psychologists, are the dominant themes.

O artigo propõe uma viagem histórica institucional através das características de produção de conhecimento em psicologia política num espaço acadêmico (Universidade Nacional de San Luis, Argentina), suas influências, e sua articulação com a formação do grau profissional em psicologia. Do ponto de vista proposto, psicologia política reflete sobre pessoas e analisa sua dimensão subjetiva, recuperando a condição humana a partir das mediações históricas micro e macro sociais que atravessam-la. A concepção e do exercício do poder; a distribuição de conhecimento socialmente validado; controle social; direitos humanos e representações sociais de setores da realidade, psicologia econômica, participação política, saúde mental e formação de psicólogos, são os temas dominantes.

Cet article propose un voyage historique institutionnel à travers les caractéristiques de production de connaissances en psychologie politique dans un domaine académique particulier (Université Nationale de San Luis, en Argentine), ses influences et son articulation avec la formation de diplôme professionnel en psychologie. De ce point de vue, psychologie politique reflète sur les personnes et analyse leur dimension subjective, la récupération de la condition humaine à partir de médiations historiques sociales micro et macro qui le traversent. Conception et exercice du pouvoir ; la diffusion des connaissances socialement validée; contrôle social ; les droits de l'homme et les représentations sociales des secteurs de la réalité, psychologie économique, participation politique, santé mentale et formation des psychologues, sont les thèmes dominants.

Aspartic proteinases in Antarctic fish.

The present review surveys several recent studies of the aspartic proteinases from Antarctic Notothenioidei, a dominating fish group that has developed a number of adjustments at the molecular level to maintain metabolic function at low temperatures. Given the unique peculiarities of the Antarctic environment, studying the features of Antarctic aspartic proteinases could provide new insights into the role of these proteins in fish physiology. We describe here: (1) the biochemical properties of a cathepsin D purified from the liver of the hemoglobinless icefish Chionodraco hamatus; (2) the biochemical characterization of Trematomus bernacchii pepsins variants A1 and A2 obtained by heterologous expression in bacteria; and (3) the identification of two closely related, novel aspartic proteinases from the liver of the two Antarctic fish species mentioned above. Overall, the results show that Notothenioidei aspartic proteinases display a number of characteristics that are remarkably different from those of mammalian aspartic proteinases, including high turnover number or high catalytic efficiency. We have named the newly identified aspartic proteinases "Nothepsins" and classified them relative to aspartic proteinases from other species.