RESUMO
The Hsp70 is an essential molecular chaperone in protein metabolism since it acts as a pivot with other molecular chaperone families. Several co-chaperones act as regulators of the Hsp70 action cycle, as for instance Hip (Hsp70-interacting protein). Hip is a tetratricopeptide repeat protein (TPR) that interacts with the ATPase domain in the Hsp70-ADP state, stabilizing it and preventing substrate dissociation. Molecular chaperones from protozoans, which can cause some neglected diseases, are poorly studied in terms of structure and function. Here, we investigated the structural features of Hip from the protozoa Leishmania braziliensis (LbHip), one of the causative agents of the leishmaniasis disease. LbHip was heterologously expressed and purified in the folded state, as attested by circular dichroism and intrinsic fluorescence emission techniques. LbHip forms an elongated dimer, as observed by analytical gel filtration chromatography, analytical ultracentrifugation and small angle X-ray scattering (SAXS). With the SAXS data a low resolution model was reconstructed, which shed light on the structure of this protein, emphasizing its elongated shape and suggesting its domain organization. We also investigated the chemical-induced unfolding behavior of LbHip and two transitions were observed. The first transition was related to the unfolding of the TPR domain of each protomer and the second transition of the dimer dissociation. Altogether, LbHip presents a similar structure to mammalian Hip, despite their low level of conservation, suggesting that this class of eukaryotic protein may use a similar mechanism of action.
Assuntos
Proteínas de Choque Térmico HSP70/química , Proteínas de Choque Térmico HSP70/ultraestrutura , Leishmania braziliensis/enzimologia , Modelos Químicos , Modelos Moleculares , Conformação ProteicaRESUMO
The red gum lerp psyllid, Glycaspis brimblecombei Moore, 1964 (Hemiptera: Aphalaridae), an insect pest originating in Australia and which feeds only on Eucalyptus L'Hér. (Myrtales: Myrtaceae) plants, has spread to several countries. The populations of this insect commonly reach high populations on Eucalyptus plants since its entry into Brazil, and also indicated an unrecorded behavioral. The objectives of this study were to describe a peculiar adaptation in the feeding habit of G. brimblecombei and to register the new habit. The oviposition and feeding by G. brimblecombei, commonly, on the leaves of Eucalyptus, started to occur, also, on lignified twigs. This suggests a not yet recorded adaptation of this insect to reduce insect × plant intraspecific competition.
Assuntos
Eucalyptus , Hemípteros , Animais , Insetos , Oviposição , Folhas de PlantaRESUMO
Vegetation cover may show diversity and composition patterns of the soil invertebrate community, as a function of litter quantity and quality in a specific habitat. The objective of this work was to characterize the distribution of edaphic fauna in different monocultures. The study was carried out at Chapada Grande farm in Regeneração, PI. Four monoculture areas were chosen: no-tillage soybean, eucalyptus, pasture, and a preserved native cerrado forest. Soil fauna was collected in a dry and wet period by pitfall traps containing 4% formaldehyde. The edaphic fauna was evaluated by the number of individuals per trap per day, average richness and richness, Shannon diversity index and Pielou uniformity index. Data were submitted to analysis of variance and multivariate Principal Component Analysis (PCA). The highest number of individuals per day trap and of average richness were registered in the pasture, eucalyptus and forest areas in both periods, while soybean showed lower values with predominance of Coleoptera and Formicidae groups. The pasture and forest areas showed of higher Shannon index values in the two evaluated seasons, probably due to higher contributions organic residues in the soil that favors the shelter, feeding and reproduction conditions. Regarding the Pielou index, the soybean system showed higher values in this variable. The Aranae, Coleoptera, Formicidae and Diptera groups predominated in the humid period, while Coleoptera and Formicidae predominated in the dry period. Systems that generate greater accumulation of residues harbor a greater diversity of invertebrates of the edaphic fauna. Seasonality had an effect on all variables analyzed and the wet period showed more expressive values.
Assuntos
Biodiversidade , Pradaria , Animais , Ecossistema , Florestas , Humanos , SoloRESUMO
An amendment to this paper has been published and can be accessed via a link at the top of the paper.
RESUMO
Temperature affects the development, population dynamics, reproduction and population size of insects. Thaumastocoris peregrinus Carpintero et Dellape (Heteroptera: Thaumastocoridae) is a eucalyptus pest. The objective of this study was to determine biological and life table parameters of T. peregrinus on Eucalyptus benthamii at five temperatures (18 °C; 22 °C; 25 °C; 27 °C and 30 °C) with a relative humidity (RH) of 70 ± 10% and photoperiod of 12 hours. The duration of each instar and the longevity of this insect were inversely proportional to the temperature, regardless of sex. The nymph stage of T. peregrinus was 36.4 days at 18 °C and 16.1 days at 30 °C. The pre-oviposition period was 5.1 days at 30 °C and 13.1 days at 18 °C and that of oviposition was 7.6 days at 30 °C and 51.2 days at 22 °C. The generation time (T) of T. peregrinus was 27.11 days at 22 °C and 8.22 days at 30 °C. Lower temperatures reduced the development and increased the life stage duration of T. peregrinus. Optimum temperatures for T. peregrinus development and reproduction were 18 and 25 °C, respectively.
Assuntos
Heterópteros/crescimento & desenvolvimento , Animais , Eucalyptus , Feminino , Heterópteros/genética , Tábuas de Vida , Longevidade , Masculino , Ninfa , Oviposição , Periodicidade , Controle de Pragas/métodos , Fotoperíodo , Dinâmica Populacional , Reprodução , TemperaturaRESUMO
The red gum lerp psyllid, Glycaspis brimblecombei Moore, 1964 (Hemiptera: Aphalaridae), an insect pest originating in Australia and which feeds only on Eucalyptus L'Hér. (Myrtales: Myrtaceae) plants, has spread to several countries. The populations of this insect commonly reach high populations on Eucalyptus plants since its entry into Brazil, and also indicated an unrecorded behavioral. The objectives of this study were to describe a peculiar adaptation in the feeding habit of G. brimblecombei and to register the new habit. The oviposition and feeding by G. brimblecombei, commonly, on the leaves of Eucalyptus, started to occur, also, on lignified twigs. This suggests a not yet recorded adaptation of this insect to reduce insect × plant intraspecific competition.
O psilídeo de concha, Glycaspis brimblecombei Moore, 1964 (Hemiptera: Aphalaridae), um inseto praga originário da Austrália e que se alimenta apenas de plantas de Eucalyptus L'Hér. (Myrtales: Myrtaceae), se espalhou por vários países. Esse inseto, geralmente, atinge grandes populações em plantas de Eucalyptus desde sua entrada no Brasil e, também, indicou um comportamento diferente. Os objetivos deste estudo foram descrever uma adaptação peculiar no hábito alimentar de G. brimblecombei e registrar o novo hábito. A oviposição e alimentação por G. brimblecombei, geralmente, nas folhas de Eucalyptus, passaram a ocorrer, também, em ramos lignificados. Isso sugere uma adaptação diferente desse inseto para reduzir a competição intraespecífica inseto × planta.
Assuntos
Animais , Oviposição , Comportamento , Eucalyptus/parasitologia , Hemípteros/crescimento & desenvolvimentoRESUMO
Abstract The red gum lerp psyllid, Glycaspis brimblecombei Moore, 1964 (Hemiptera: Aphalaridae), an insect pest originating in Australia and which feeds only on Eucalyptus L'Hér. (Myrtales: Myrtaceae) plants, has spread to several countries. The populations of this insect commonly reach high populations on Eucalyptus plants since its entry into Brazil, and also indicated an unrecorded behavioral. The objectives of this study were to describe a peculiar adaptation in the feeding habit of G. brimblecombei and to register the new habit. The oviposition and feeding by G. brimblecombei, commonly, on the leaves of Eucalyptus, started to occur, also, on lignified twigs. This suggests a not yet recorded adaptation of this insect to reduce insect × plant intraspecific competition.
Resumo O psilídeo de concha, Glycaspis brimblecombei Moore, 1964 (Hemiptera: Aphalaridae), um inseto praga originário da Austrália e que se alimenta apenas de plantas de Eucalyptus L'Hér. (Myrtales: Myrtaceae), se espalhou por vários países. Esse inseto, geralmente, atinge grandes populações em plantas de Eucalyptus desde sua entrada no Brasil e, também, indicou um comportamento diferente. Os objetivos deste estudo foram descrever uma adaptação peculiar no hábito alimentar de G. brimblecombei e registrar o novo hábito. A oviposição e alimentação por G. brimblecombei, geralmente, nas folhas de Eucalyptus, passaram a ocorrer, também, em ramos lignificados. Isso sugere uma adaptação diferente desse inseto para reduzir a competição intraespecífica inseto × planta.
RESUMO
Abstract Vegetation cover may show diversity and composition patterns of the soil invertebrate community, as a function of litter quantity and quality in a specific habitat. The objective of this work was to characterize the distribution of edaphic fauna in different monocultures. The study was carried out at Chapada Grande farm in Regeneração, PI. Four monoculture areas were chosen: no-tillage soybean, eucalyptus, pasture, and a preserved native cerrado forest. Soil fauna was collected in a dry and wet period by pitfall traps containing 4% formaldehyde. The edaphic fauna was evaluated by the number of individuals per trap per day, average richness and richness, Shannon diversity index and Pielou uniformity index. Data were submitted to analysis of variance and multivariate Principal Component Analysis (PCA). The highest number of individuals per day trap and of average richness were registered in the pasture, eucalyptus and forest areas in both periods, while soybean showed lower values with predominance of Coleoptera and Formicidae groups. The pasture and forest areas showed of higher Shannon index values in the two evaluated seasons, probably due to higher contributions organic residues in the soil that favors the shelter, feeding and reproduction conditions. Regarding the Pielou index, the soybean system showed higher values in this variable. The Aranae, Coleoptera, Formicidae and Diptera groups predominated in the humid period, while Coleoptera and Formicidae predominated in the dry period. Systems that generate greater accumulation of residues harbor a greater diversity of invertebrates of the edaphic fauna. Seasonality had an effect on all variables analyzed and the wet period showed more expressive values.
Resumo A cobertura vegetal pode mostrar padrões de diversidade e composição da comunidade de invertebrados do solo, em função da quantidade e qualidade da serapilheira em determinado habitat específico. O objetivo deste trabalho foi caracterizar a distribuição da fauna edáfica em diferentes monocultivos. O estudo foi realizado na fazenda Chapada Grande no município de Regeneração, PI. Foram escolhidas quatro áreas de monocultivos: soja em sistema de plantio direto, eucalipto, pastagem, além de uma mata nativa de cerrado preservada. Foram realizadas coletas da fauna do solo, em período seco e úmido, por meio de armadilhas do tipo pitfall contendo 4% de formol. A fauna edáfica foi avaliada pelo número de indivíduos por armadilha por dia, riqueza e riqueza média, índice de diversidade de Shannon e índice de uniformidade de Pielou. Os dados foram submetidos à análise de variância e à análise multivariada de Componentes Principais (ACP). O maior número de indivíduos por armadilha dia e de riqueza média foram registrados nas áreas pastagem, eucalipto e mata nos dois períodos, enquanto que a soja mostrou valores inferiores com predomínio dos grupos Coleoptera e Formicidae. As áreas de pastagem e mata mostraram maiores valores de índice de Shannon nas duas épocas avaliadas provavelmente em função de maiores aportes de resíduos orgânicos no solo que favorece as condições de abrigo, alimentação e reprodução. Em relação ao índice de Pielou o sistema com soja mostrou maiores valores nessa variável. Os grupos Araneae, Coleoptera, Formicidae e Diptera predominaram no período úmido, enquanto Coleoptera e Formicidae se destacaram no período seco. Sistemas que geram maior acúmulo de resíduos abrigam uma maior diversidade de invertebrados da fauna edáfica. A sazonalidade apresentou efeito sobre todas as variáveis analisadas sendo que o período úmido mostrou valores mais expressivos.
Assuntos
Humanos , Animais , Pradaria , Biodiversidade , Solo , Florestas , EcossistemaRESUMO
Hep1 is a mitochondrial Hsp70 (mtHsp70) co-chaperone that presents a zinc finger domain essential for its function. This co-chaperone acts to maintain mtHsp70 in its soluble and functional state. In this work, we have demonstrated that Leishmania braziliensis mtHsp70 (LbmtHsp70) is also dependent on the assistance of Hep1. To understand the L. braziliensis Hep1 (LbHep1) structure-function relationship, we produced LbHep1 and two truncated mutants corresponding to the C-terminal zinc finger domain and the N-terminal region. We observed that LbHep1 is composed of an unfolded N-terminal region and a ß-sheet-folded C-terminal domain, which holds the zinc-binding motif. Both LbHep1 and the zinc finger domain construction maintained LbmtHsp70 solubility in co-expression systems after cell lysis. In solution, LbHep1 behaved as a highly elongated monomer, probably due to the unfolded N-terminal region. Furthermore, we also observed that the zinc ion interacted with LbHep1 with high affinity and was critical for LbHep1 structure and stability because its removal from LbHep1 solutions altered the protein structure and stability. In vitro, LbHep1 protected, in sub-stoichiometric fashion, LbmtHsp70 from thermally induced aggregation but did not present intrinsic chaperone activity on model client proteins. Therefore, LbHep1 is a specific chaperone for LbmtHsp70.
Assuntos
Proteínas de Choque Térmico HSP70/química , Proteínas Mitocondriais/química , Chaperonas Moleculares/química , Proteínas de Choque Térmico HSP70/metabolismo , Leishmania braziliensis/química , Mitocôndrias/química , Mitocôndrias/genética , Proteínas Mitocondriais/genética , Chaperonas Moleculares/genética , Ligação Proteica , Dobramento de Proteína , Estrutura Secundária de Proteína , Dedos de Zinco/genéticaRESUMO
Mitochondrial Hsp70 is involved in both protein import and folding process, among other essential functions. In mammalian cells, due to its role in the malignant process, it receives the name of mortalin. Despite its importance in protein and mitochondrial homeostasis, mortalin tends to self-aggregate in vitro and in vivo, the later leads to mitochondrial biogenesis failure. Recently, a zinc-finger protein, named Hsp70-escort protein 1 (Hep1, also called Zim17/TIM15/DNLZ), was described as an essential human mitochondrial mortalin co-chaperone which avoids its self-aggregation. Here, we report structural studies of the human Hep1 (hHep1). The results indicate that hHep1 shares some structural similarities with the yeast ortholog despite the low identity and functional differences. We also observed that hHep1 oligomerizes in a concentration-dependent fashion and that the zinc ion, which is essential for hHep1 in vivo function, has an important protein-structure stabilizing effect.
Assuntos
Proteínas de Choque Térmico HSP70/metabolismo , Mitocôndrias/metabolismo , Chaperonas Moleculares/metabolismo , Proteínas de Choque Térmico HSP70/química , Humanos , Hidrodinâmica , Mitocôndrias/efeitos dos fármacos , Chaperonas Moleculares/química , Chaperonas Moleculares/isolamento & purificação , Dobramento de Proteína/efeitos dos fármacos , Multimerização Proteica/efeitos dos fármacos , Estabilidade Proteica/efeitos dos fármacos , Estrutura Quaternária de Proteína , Estrutura Terciária de Proteína , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , Relação Estrutura-Atividade , Triptofano/metabolismo , Zinco/farmacologia , Dedos de ZincoRESUMO
Abstract Vegetation cover may show diversity and composition patterns of the soil invertebrate community, as a function of litter quantity and quality in a specific habitat. The objective of this work was to characterize the distribution of edaphic fauna in different monocultures. The study was carried out at Chapada Grande farm in Regeneração, PI. Four monoculture areas were chosen: no-tillage soybean, eucalyptus, pasture, and a preserved native cerrado forest. Soil fauna was collected in a dry and wet period by pitfall traps containing 4% formaldehyde. The edaphic fauna was evaluated by the number of individuals per trap per day, average richness and richness, Shannon diversity index and Pielou uniformity index. Data were submitted to analysis of variance and multivariate Principal Component Analysis (PCA). The highest number of individuals per day trap and of average richness were registered in the pasture, eucalyptus and forest areas in both periods, while soybean showed lower values with predominance of Coleoptera and Formicidae groups. The pasture and forest areas showed of higher Shannon index values in the two evaluated seasons, probably due to higher contributions organic residues in the soil that favors the shelter, feeding and reproduction conditions. Regarding the Pielou index, the soybean system showed higher values in this variable. The Aranae, Coleoptera, Formicidae and Diptera groups predominated in the humid period, while Coleoptera and Formicidae predominated in the dry period. Systems that generate greater accumulation of residues harbor a greater diversity of invertebrates of the edaphic fauna. Seasonality had an effect on all variables analyzed and the wet period showed more expressive values.
Resumo A cobertura vegetal pode mostrar padrões de diversidade e composição da comunidade de invertebrados do solo, em função da quantidade e qualidade da serapilheira em determinado habitat específico. O objetivo deste trabalho foi caracterizar a distribuição da fauna edáfica em diferentes monocultivos. O estudo foi realizado na fazenda Chapada Grande no município de Regeneração, PI. Foram escolhidas quatro áreas de monocultivos: soja em sistema de plantio direto, eucalipto, pastagem, além de uma mata nativa de cerrado preservada. Foram realizadas coletas da fauna do solo, em período seco e úmido, por meio de armadilhas do tipo pitfall contendo 4% de formol. A fauna edáfica foi avaliada pelo número de indivíduos por armadilha por dia, riqueza e riqueza média, índice de diversidade de Shannon e índice de uniformidade de Pielou. Os dados foram submetidos à análise de variância e à análise multivariada de Componentes Principais (ACP). O maior número de indivíduos por armadilha dia e de riqueza média foram registrados nas áreas pastagem, eucalipto e mata nos dois períodos, enquanto que a soja mostrou valores inferiores com predomínio dos grupos Coleoptera e Formicidae. As áreas de pastagem e mata mostraram maiores valores de índice de Shannon nas duas épocas avaliadas provavelmente em função de maiores aportes de resíduos orgânicos no solo que favorece as condições de abrigo, alimentação e reprodução. Em relação ao índice de Pielou o sistema com soja mostrou maiores valores nessa variável. Os grupos Araneae, Coleoptera, Formicidae e Diptera predominaram no período úmido, enquanto Coleoptera e Formicidae se destacaram no período seco. Sistemas que geram maior acúmulo de resíduos abrigam uma maior diversidade de invertebrados da fauna edáfica. A sazonalidade apresentou efeito sobre todas as variáveis analisadas sendo que o período úmido mostrou valores mais expressivos.