Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / No presente trabalho à feita a descriÃÃo de trÃs genes distintos que codificam lectinas ou proteÃnas relacionadas à lectina de Vatairea macrocarpa. As sequÃncias foram obtidas pela amplificaÃÃo de DNA genÃmico e cDNA de folhas utilizando primers semi-degenerados construÃdos a partir da informaÃÃo da sequÃncia de aminoÃcidos da lectina VML depositada no GenBank. O resultado do sequenciamento revelou a presenÃa de trÃs contigs. O contig1 corresponde à lectina VML desde que se assuma que a lectina depositada VML contenha heterogeneidades ou ambiguidades decorrentes na degradaÃÃo de Edman. A traduÃÃo dos contigs 2 e 3 mostram identidade de sequÃncia de 77% quando comparadas com VML. As sequÃncias, apesar de apresentar regiÃes conservadas, mostram diferenÃas de aminoÃcidos nos sÃtios de N-glicosilaÃÃo, sÃtios de ligaÃÃo a carboidrato e metais alÃm da presenÃa de resÃduos de cisteÃna sugerindo que tais proteÃnas podem ter outras atividades biolÃgicas. A anÃlise da sequÃncia obtida pelo 3â RACE se mostrou complementar ao contig3. Sendo assim, a sequÃncia hÃbrida contig3/contigA possui 2 resÃduos de cisteÃna alÃm de revelar diferenÃas de aminoÃcidos na regiÃo C-terminal quando alinhada com outras lectinas de leguminosas. AnÃlises filogenÃticas revelaram que os contigs observados formam um grupo monofiletico e tem alta similaridade com as lectinas de Sohora japonica e Robinia pseudoacacia, alÃm da proteÃna relacionada à lectina de Cladrastis lutea. / In this paper is made a description of three distinct genes that encode Vatairea macrocarpa lectin and related proteins. The sequences were obtained by amplification of genomic DNA and cDNA of leaves using semi - degenerate primers constructed from the information of the amino acid sequence of VML lectin deposited in GenBank. The result of sequencing rev eals the presence of three different genes, called contig 1, 2 and 3 . The VML lectin corresponds to contig1 long as one assumes that the lectin contains heterogeneities deposited VML or ambiguities arising in the Edman degradation . The translation of cont igs 2 and 3 show sequence identity of 77% compared to VML. Sequences, despite having conserved regions show differences in amino acid N - glycosylation sites, carbohydrate binding sites and metals and the presence of cysteine residues suggests that these pro teins may have other biological activities . The analysis of the sequence obtained by 3 'RACE proved complementary to contig3. Thus, the sequence contig3/contigA hybrid has two cysteine residues in addition to revealing differences in amino acid C - terminal region when aligned with other legume lectins. Phylogenetic analysis revealed that the observed contigs form a monophyletic group and has high similarity with lectins from Robinia pseudoacacia Sohora japonica and, in addition to the lectin - related protein Cladrastis lutea .

Les Heat Shock Proteins 70 kDa (HSP70) sont considérées comme les membres les plus conservés de la superfamille des HSP. Ces protéines chaperonnes sont indispensables à tous les organismes vivants par leur implication dans de nombreuses voies de signalisation cellulaire et dans la gestion de multiples facteurs de stress environnementaux (température, pollution, salinité, radiation). Largement utilisée en écologie comme biomarqueur de stress, la famille des HSP70 constitue également une cible thérapeutique privilégiée dans les recherches contre les maladies neurodégénératives et les cancers. Dans le cytosol, une large variété de HSP70 a été observée chez quelques espèces modèles (drosophile, levure, humain). Néanmoins, cette diversité reste méconnue au sein du phylum Arthropoda, et plus particulièrement chez les décapodes. La diversité des HSP70 cytosoliques a été étudiée à partir de 735 séquences issues 198 espèces d’arthropodes, dont 142 séquences de décapodes obtenues durant ces travaux. Les analyses de phylogénie moléculaire ont permis la description d’au moins trois groupes distincts de HSP70 cytosoliques chez les arthropodes, comprenant chacun plusieurs subdivisions méconnues jusqu’à présent. Une nouvelle classification et un modèle évolutif des HSP70 cytosoliques sont proposés pour le phylum Arthropoda. Les profils d’expression observés dans ces groupes remettent en cause la catégorisation des HSP70 selon leurs caractère constitutif (HSC70) ou inductible (HSP70). Les spécificités structurales géniques et protéiques observées pour chacune de ces formes reflèteraient différentes capacités d’interaction des HSP70 avec leurs co-chaperons et autres cofacteurs. / The 70 kDa Heat Shock Proteins (HSP70) are considered the most conserved members of the HSP family. These molecular chaperones are primordial to living beings, because of their implications in many cellular pathways and the management of multiple environmental stress factors (e. g., temperature, pollutants, salinity, radiations). Widely used in ecology as a biomarker of environmental stress, the HSP70 family is also a privileged therapeutic target for neurodegenerative diseases and cancers. In the cytosol, a wide variety of HSP70 is observed in few model species (Drosophila, human, yeast). Nevertheless, the diversity of cytosolic HSP70 remains unclear amongst the Arthropoda phylum, especially within decapods. The diversity studies of cytosolic HSP70 were based on 735 sequences from 198 arthropod species, including 142 sequences from decapods obtained during this work. Molecular phylogeny analyses revealed at least three distinct groups of HSP70 within arthropods, comprising several unrecognised subdivisions. This study proposes a new classification and an evolutionary model of cytosolic HSP70 amongst the Arthropoda phylum. The expression profiles observed in each group lead to reconsider the HSP70 classification according to their constitutive (HSC70) or inducible (HSP70) features. The observed structural specificities of genes and proteins, relative to each form of HSP70, will probably have to be linked to distinct interactions with cochaperones or other co-factors.

ALVES FILHO, João Garcia. Clonagem, sequenciamento e caracterização parcial dos genes relacionados à lectina de Vatairea macrocarpa. 2008. 81 f. Dissertação (Mestrado)-Universidade Federal do Ceará, Fortaleza-CE, 2008. / Submitted by Eric Santiago (erichhcl@gmail.com) on 2016-05-25T14:10:53Z No. of bitstreams: 1 2008_dis_jgalvesfilho.pdf: 1626131 bytes, checksum: fbd1ed851edb7139baaf9677e39e516a (MD5) / Approved for entry into archive by José Jairo Viana de Sousa (jairo@ufc.br) on 2016-07-05T20:59:57Z (GMT) No. of bitstreams: 1 2008_dis_jgalvesfilho.pdf: 1626131 bytes, checksum: fbd1ed851edb7139baaf9677e39e516a (MD5) / Made available in DSpace on 2016-07-05T20:59:57Z (GMT). No. of bitstreams: 1 2008_dis_jgalvesfilho.pdf: 1626131 bytes, checksum: fbd1ed851edb7139baaf9677e39e516a (MD5) Previous issue date: 2008 / In this paper is made a description of three distinct genes that encode Vatairea macrocarpa lectin and related proteins. The sequences were obtained by amplification of genomic DNA and cDNA of leaves using semi - degenerate primers constructed from the information of the amino acid sequence of VML lectin deposited in GenBank. The result of sequencing rev eals the presence of three different genes, called contig 1, 2 and 3 . The VML lectin corresponds to contig1 long as one assumes that the lectin contains heterogeneities deposited VML or ambiguities arising in the Edman degradation . The translation of cont igs 2 and 3 show sequence identity of 77% compared to VML. Sequences, despite having conserved regions show differences in amino acid N - glycosylation sites, carbohydrate binding sites and metals and the presence of cysteine residues suggests that these pro teins may have other biological activities . The analysis of the sequence obtained by 3 'RACE proved complementary to contig3. Thus, the sequence contig3/contigA hybrid has two cysteine residues in addition to revealing differences in amino acid C - terminal region when aligned with other legume lectins. Phylogenetic analysis revealed that the observed contigs form a monophyletic group and has high similarity with lectins from Robinia pseudoacacia Sohora japonica and, in addition to the lectin - related protein Cladrastis lutea. / No presente trabalho é feita a descrição de três genes distintos que codificam lectinas ou proteínas relacionadas à lectina de Vatairea macrocarpa. As sequências foram obtidas pela amplificação de DNA genômico e cDNA de folhas utilizando primers semi-degenerados construídos a partir da informação da sequência de aminoácidos da lectina VML depositada no GenBank. O resultado do sequenciamento revelou a presença de três contigs. O contig1 corresponde à lectina VML desde que se assuma que a lectina depositada VML contenha heterogeneidades ou ambiguidades decorrentes na degradação de Edman. A tradução dos contigs 2 e 3 mostram identidade de sequência de 77% quando comparadas com VML. As sequências, apesar de apresentar regiões conservadas, mostram diferenças de aminoácidos nos sítios de N-glicosilação, sítios de ligação a carboidrato e metais além da presença de resíduos de cisteína sugerindo que tais proteínas podem ter outras atividades biológicas. A análise da sequência obtida pelo 3’ RACE se mostrou complementar ao contig3. Sendo assim, a sequência híbrida contig3/contigA possui 2 resíduos de cisteína além de revelar diferenças de aminoácidos na região C-terminal quando alinhada com outras lectinas de leguminosas. Análises filogenéticas revelaram que os contigs observados formam um grupo monofiletico e tem alta similaridade com as lectinas de Sohora japonica e Robinia pseudoacacia, além da proteína relacionada à lectina de Cladrastis lutea.

Ma thèse s'inscrit dans l'étude des modifications du globule rouge humain induites par P. falciparum. Ces modifications qui représentent une remarquable adaptation du parasite à un environnement plus complexe qu'il n'y paraît au premier abord et expliquent sa persistance chez l'Homme sont détaillées dans une revue et un chapitre de livre dont je suis co-auteur. Mes travaux de recherche ont porté sur la caractérisation fonctionnelle des structures de Maurer, un compartiment membranaire exporté par le parasite dans le globule rouge parasitaire et directement lié à la physiopathologie du paludisme grave. J'ai contribué à la caractérisation fonctionnelle de nouvelles protéines de ces structures, codées par trois familles multigéniques sub-télomériques en cluster avec la famille Pfmc-2tm, et présentant de façon étonnante un fort degré de conservation (article 1). La diminution d'expression de ces gènes, obtenue par titration d'un facteur transcriptionnel, entraine un défaut de libération des mérozoïtes. Mon deuxième projet porte sur l'identification des modalités d'export de la protéine transmembranaire résidente des structures de Maurer PfSBP1. Mes travaux montrent que PfSBP1 est exportée sous forme soluble dans le cytoplasme érythrocytaire, en interaction avec le complexe chaperon parasitaire PfTCP1 (article 2). / Plasmodium falciparum causes the most severe forms of human malaria, a pathology associated with the erythrocytic asexual stages of the parasite. My work focused on the remodeling of the infected erythrocytes induced by P. falciparum and detailed in a review and a book chapter that I co-authored. These modifications illustrate a remarkable adaptation of P. falciparum resulting in its persistence in humans. My PhD thesis was dedicated to the functional characterization of Maurer's clefts, a membrane compartment transposed by the parasite in the cytoplasm of its host cell, and central to the export of virulence factors to the host cell surface. I have conducted two projects and contributed first to the functional characterization of novel exported protein encoded by three highly conserved multigene sub-telomeric families in cluster with the Pfmc-2tm family. Down regulation of these gene families by promoter titration impacted the release of infectious merozoites from the host cell (annex 1). My second project was dedicated to the identification of the modality of export of the resident and Maurer's clefts transmembrane protein PfSBP1. I have shown that PfSBP1 is exported as a soluble protein in the host cell cytoplasm in interaction with the parasite Thermosome complex protein 1 (PfTCP1) chaperone complex (annex 2).

Les plantes sont soumises durant leur vie à de nombreux stress environnementaux. Face à ces contraintes, les végétaux ont développé au cours de l'évolution différentes stratégies. La plus emblématique est la mise en place du métabolisme spécialisé, représenté par une grande diversité chimique et fonctionnelle. Bien que ce métabolisme soit de plus en plus étudié ces dernières années, de nombreuses lacunes persistes à son propos, liées notamment (i) à la complexité des modifications métabolomiques engendrées par la perception de stress, (ii) aux coûts et avantages que ces métabolites imputent à la plante les accumulant, et (iii) aux voies métaboliques menant à cette diversité de composés. Pour appréhender ces différentes problématiques, nous avons adopté une stratégie combinant des approches de phytochimie, de biologie moléculaire et de génétique. Dans un premier temps, nous avons étudié les changements métaboliques globaux engendrés par l’application de deux stress environnementaux, l’ozone et la blessure mécanique, sur une plante modèle au laboratoire, le panais, en fonction du temps. Les résultats de ces travaux nous ont permis d’identifier 40 métabolites différentiellement accumulés dans ces conditions, dont certaines furocoumarines. Par la suite, nous avons focalisé notre étude sur ces molécules en évaluant leurs profils d’accumulation, en condition de stress par blessures mécaniques, par la biais d’analyses différentielles. A partir de ces données, nous avons initié la recherche et l'identification de gènes candidats potentiellement impliqués dans cette voie à partir de plusieurs banques transcriptomiques et génomiques de panais. La fonction des gènes sélectionnés a été évalué par des approches d'expression hétérologue dans la levure. En parallèle de ces travaux, nous avons développé une stratégie destinée à mieux comprendre le coût métabolique de la synthèse de métabolites spécialisés. Pour ce faire, nous avons adapté aux furocoumarines une technique de clonage multigénique permettant de transférer dans une plante, et en une seule opération, plusieurs gènes impliqués dans la même voie de biosynthèse. Cette méthode nous a permis d'initier la génération de lignées stables ayant intégré les deux premiers gènes de la voie. Ces plantes seront comparées à des plantes sauvages et permettront ainsi d’étudier les coûts métaboliques et physiologiques de l’introduction de cette nouvelle voie de biosynthèse ainsi que ses bénéfices en termes de défense de la plante. / Plants are subjected to many environmental stresses during their life. Faced with these constraints, plants have developed different strategies during their evolution. The most emblematic is the establishment of a specialized metabolism, represented by a great chemical and functional diversity. Although this metabolism has been studied more and more in recent years, many gaps remain, related in particular (i) to the complexity of the metabolomic changes generated by the perception of stress, (ii) to the costs and benefits that these metabolites impute to the producing plant, and (iii) to the metabolic pathways leading to the diversity of compounds. To cope with these different issues, we adopted a strategy combining approaches of phytochemistry, molecular biology and genetics. First, we studied global metabolic changes caused by the application of two environmental stresses, ozone and mechanical wounding, on parsnip. The obtained results allowed us to identify 40 metabolites differentially accumulated under these conditions, including some furocoumarins. Subsequently, we focused our study on these molecules by evaluating their accumulation profiles under mechanical wounding stress condition, using differential analyzes. From this data, we initiated the search and identification of candidate genes potentially involved in this pathway based on transcriptomic and genomic parsnip libraries analyses. The function of the selected genes was evaluated by heterologous expression approach in yeast. In parallel to this work, we have developed a strategy to better understand the metabolic cost of specialized metabolites synthesis. To do this, we have adapted a multigene cloning method to furocoumarines, allowing to transfer several genes involved in the same pathway in a plant, in a single operation. This method allowed us to initiate the generation of stable lines having integrated the first two genes of the pathway. These plants will be compared to wild plants and will thus allow to study the metabolic and physiological costs of the introduction of this new biosynthetic pathway and its benefits in terms of plant defense.