Sabiia Seb
PortuguêsEspañolEnglish
Embrapa
        Busca avançada

Botão Atualizar


Botão Atualizar

Ordenar por: RelevânciaAutorTítuloAnoImprime registros no formato resumido
Registros recuperados: 15
Primeira ... 1 ... Última
Imagem não selecionada

Imprime registro no formato completo
11[beta]-hydroxysteroid dehydrogenase-type 2 evolved from an ancestral 17[beta]-hydroxysteroid dehydrogenase-type 2 Nature Precedings
Michael E. Baker.
11[beta]-hydroxysteroid dehydrogenase type-2 (11[beta]-HSD2) regulates the local concentration of cortisol that can activate the glucocorticoid receptor and mineralocorticoid receptor, as well as the concentration of 11-keto-testosterone, the active androgen in fish. Similarly, 17[beta]-HSD2 regulates the levels of testosterone and estradiol that activate the androgen receptor and estrogen receptor, respectively. Interestingly, although human 11[beta]-HSD2 and 17[beta]-HSD2 act at different positions on different steroids, these enzymes are paralogs. Despite the physiological importance of 11[beta]-HSD2 and 17[beta]-HSD2, details of their origins and divergence from a common ancestor are not known. An opportunity to understand their evolution is...
Tipo: Manuscript Palavras-chave: Cancer; Developmental Biology; Pharmacology; Bioinformatics; Evolutionary Biology.
Ano: 2010 URL: http://precedings.nature.com/documents/4649/version/1
Imagem não selecionada

Imprime registro no formato completo
3D model of amphioxus steroid receptor complexed with estradiol Nature Precedings
Michael E. Baker; David J. Chang.
The origins of signaling by vertebrate steroids are not fully understood. An important advance was the report that an estrogen-binding steroid receptor [SR] is present in amphioxus, a basal chordate with a similar body plan as vertebrates. To investigate the evolution of estrogen binding to steroid receptors, we constructed a 3D model of amphioxus SR complexed with estradiol. This 3D model indicates that although the SR is activated by estradiol, some interactions between estradiol and human ER[alpha] are not conserved in the SR, which can explain the low affinity of estradiol for the SR. These differences between the SR and ER[alpha] in the steroid-binding domain are sufficient to suggest that another steroid is the physiological regulator of the SR....
Tipo: Manuscript Palavras-chave: Cancer; Developmental Biology; Bioinformatics; Evolutionary Biology.
Ano: 2009 URL: http://precedings.nature.com/documents/3316/version/1
Imagem não selecionada

Imprime registro no formato completo
3D model of lamprey estrogen receptor with estradiol and 15[alpha]-hydroxy-estradiol Nature Precedings
Michael E. Baker; David J. Chang; Charlie Chandsawangbhuwana.
Lamprey, a basal vertebrate, contains orthologs of the estrogen receptor (ER), progesterone receptor and corticoid receptor. A perplexing property of lamprey is that 15[alpha]-hydroxy-steroids are active steroids. For example, 15[alpha]-hydroxy-estradiol [15[alpha]-OH-E2] is the estrogen, instead of estradiol (E2). To investigate how 15[alpha]-OH-E2 binds lamprey ER, we constructed a 3D model of the lamprey ER with E2 and 15[alpha]-OH-E2. Our 3D model shows that S[delta] on Met-409 can form a hydrogen bond with the 15[alpha]-hydroxyl on 15[alpha]-OH-E2. In human ER[alpha], the corresponding residue Ile-424 has a van der Waals contact with 15[alpha]-OH-E2. BLAST analysis of GenBank indicates that among vertebrate ERs, only lamprey ER contains a...
Tipo: Manuscript Palavras-chave: Developmental Biology; Ecology; Earth & Environment.
Ano: 2009 URL: http://precedings.nature.com/documents/2768/version/1
Imagem não selecionada

Imprime registro no formato completo
3D models of lamprey corticoid receptor complexed with 11-deoxycortisol and deoxycorticosterone Nature Precedings
Michael E. Baker; Kayla Y. Uh; Paiyuam Asnaashari.
The serum of Atlantic sea lamprey, a basal vertebrate, contains two corticosteroids, 11-deoxycortisol and deoxycorticosterone. Only 11-deoxycortisol has high affinity [Kd~3 nM] for the corticoid receptor [CR] in lamprey gill cytosol. To investigate the binding of 11-deoxycortisol to the CR, we constructed 3D models of lamprey CR complexed with 11-deoxycortisol and deoxycorticosterone. These 3D models reveal that Leu-220 and Met-299 in lamprey CR have contacts with the 17[alpha]-hydroxyl on 11-deoxycortisol. Lamprey CR is the ancestor of the mineralocorticoid receptor [MR] and glucocorticoid receptor [GR]. Unlike human MR and human GR, the 3D model of lamprey CR finds a van der Waals contact between Cys-227 in helix 3 and Met-264 in helix 5. Mutant...
Tipo: Manuscript Palavras-chave: Cancer; Developmental Biology; Pharmacology; Bioinformatics; Evolutionary Biology.
Ano: 2011 URL: http://precedings.nature.com/documents/6216/version/1
Imagem não selecionada

Imprime registro no formato completo
Analysis of Endocrine Disruption in Southern California Coastal Fish using an Aquatic Multi-Species Microarray Nature Precedings
Michael E. Baker; Barbara Ruggeri; James Sprague; Colleen Eckhardt; Jennifer Lapira; Ivan Wick; Laura Soverchia; Massimo Ubaldi; Alberta M. Polzonetti-Magni; Doris Vidal-Dorsch; Steven Bay; Joseph R. Gully; Jesus A. Reyes; Kevin M. Kelley; Daniel Schlenk; Ellen C. Breen; Roman Šášik; Gary Hardiman.
BACKGROUND: Endocrine disruptors include plasticizers, pesticides, detergents and pharmaceuticals. Turbot and other flatfish are used to characterize the presence of chemicals in the marine environment. Unfortunately, there are relatively few genes of turbot and other flatfish in GenBank, which limits the use of molecular tools such as microarrays and qRT-PCR to study disruption of endocrine responses in sentinel fish captured by regulatory agencies.
OBJECTIVES: A multi-gene cross species microarray was fabricated as a diagnostic tool to screen the effects of environmental chemicals in fish, for which there is minimal genomic information. The array included genes that are involved in the actions of adrenal and sex steroids, thyroid...
Tipo: Manuscript Palavras-chave: Developmental Biology; Ecology; Genetics & Genomics; Earth & Environment.
Ano: 2009 URL: http://precedings.nature.com/documents/2823/version/1
Imagem não selecionada

Imprime registro no formato completo
Dibutyltin Disrupts Glucocorticoid Receptor Function and Impairs Glucocorticoid-induced Suppression of Cytokine Production Nature Precedings
Christel Gumy; Charlie Chandsawangbhuwana; Anna A. Dzyakanchuk; Denise V. Kratschmar; Michael E. Baker; Alex Odermatt.
_Background_. Organotins are highly toxic and widely distributed environmental chemicals. Dibutyltin (DBT) is used as stabilizer in the production of polyvinyl chloride plastics, and it is also the major metabolite formed from tributyltin (TBT) _in vivo_. DBT is immunotoxic, however, the responsible targets remain to be defined. Due to the importance of glucocorticoids in immune-modulation, we investigated whether DBT could interfere with glucocorticoid receptor (GR) function.
_Methodology_. We used HEK-293 cells transiently transfected with human GR as well as rat H4IIE hepatoma cells and native human macrophages and human THP-1 macrophages expressing endogenous receptor to study organotin effects on GR function. Docking of organotins was...
Tipo: Manuscript Palavras-chave: Immunology; Pharmacology; Bioinformatics.
Ano: 2008 URL: http://precedings.nature.com/documents/2312/version/1
Imagem não selecionada

Imprime registro no formato completo
Evolution of 11[beta]-Hydroxysteroid Dehydrogenase-Type 1 and 11[beta]-Hydroxysteroid Dehydrogenase-type 3 Nature Precedings
Michael E. Baker.
A key regulator of glucocorticoid action is 11[beta]-hydroxysteroid dehydrogenase type-1 (11[beta]-HSD1), which catalyzes the conversion of cortisone to cortisol, the biologically active glucocorticoid. 11[beta]-HSD1 is a paralog of 11[beta]-HSD3, whose physiological function remains unclear. As reported here, 11[beta]-HSD3 has orthologs in sea urchin, amphioxus and Ciona, while 11[beta]-HSD1 first appears in sharks. Thus, 11[beta]HSD3 arose before the evolution of glucocorticoid signaling, suggesting different ancestral function(s) for 11[beta]-HSD3. Four perplexing findings arise from this evolutionary analysis: 1) 11[beta]-HSD1 is not present in a ray-finned fish genome, 2) zebrafish and fathead minnow contain two isoforms of 11[beta]-HSD3; 3)...
Tipo: Manuscript Palavras-chave: Developmental Biology; Ecology; Genetics & Genomics; Earth & Environment; Evolutionary Biology.
Ano: 2010 URL: http://precedings.nature.com/documents/4296/version/1
Imagem não selecionada

Imprime registro no formato completo
Hexose-6-phosphate dehydrogenase modulates the effect of inhibitors and alternative substrates of 11[beta]-hydroxysteroid dehydrogenase 1 Nature Precedings
Zoltán Balázs; Lyubomir G. Nashev; Charlie Chandsawangbhuwana; Michael E. Baker; Alex Odermatt.
Intracellular glucocorticoid reactivation is catalyzed by 11[beta]-hydroxysteroid dehydrogenase 1 (11[beta]-HSD1), which functions predominantly as a reductase in cells expressing hexose-6-phosphate dehydrogenase (H6PDH). We recently showed that the ratios of cortisone to cortisol and 7-keto- to 7-hydroxy-neurosteroids are regulated by 11[beta]-HSD1 and very much depend on co-expression with H6PDH, providing cosubstrate NADPH. Here, we investigated the impact of H6PDH on the modulation of 11[beta]-HSD1-dependent inter-conversion of cortisone and cortisol by inhibitors and alternative substrates. Using HEK-293 cells expressing 11[beta]-HSD1 or co-expressing 11[beta]-HSD1 and H6PDH, we observed significant differences of 11[beta]-HSD1 inhibition by natural...
Tipo: Manuscript Palavras-chave: Molecular Cell Biology; Pharmacology; Bioinformatics.
Ano: 2008 URL: http://precedings.nature.com/documents/2430/version/1
Imagem não selecionada

Imprime registro no formato completo
Independent elaboration of steroid hormone signaling pathways in Metazoans Nature Precedings
Gabriel V. Markov; Raquel Tavares; Chantal Dauphin-Villemant; Barbara A. Demeneix; Michael E. Baker; Vincent Laudet.
Steroid hormones regulate many physiological processes in vertebrates, nematodes and arthropods through binding to nuclear receptors (NR), a metazoan-specific family of ligand-activated transcription factors. The main steps controlling the diversification of this family are now well understood. In contrast, the origin and evolution of steroid ligands remain mysterious although this is crucial for understanding the emergence of modern endocrine systems. Using a comparative genomic approach, we analyzed complete metazoan genomes to provide a comprehensive view of the evolution of major enzymatic players implicated in steroidogenesis at the whole Metazoan scale. Our analysis reveals that steroidogenesis has been independently elaborated in the three main...
Tipo: Manuscript Palavras-chave: Cancer; Developmental Biology; Bioinformatics; Earth & Environment; Evolutionary Biology.
Ano: 2009 URL: http://precedings.nature.com/documents/3374/version/1
Imagem não selecionada

Imprime registro no formato completo
Insights from the Structure of Estrogen Receptor into the Evolution of Estrogens: Implications for Endocrine Disruption Nature Precedings
Michael E. Baker.
In the last decade, there has been important progress in understanding the origins and evolution of receptors for adrenal steroids (aldosterone, cortisol) and sex steroids (estradiol, progesterone, testosterone) due to the sequencing of genomes from animals that are at key sites in vertebrate evolution. Although the estrogen receptor [ER] appears to be the ancestral vertebrate steroid receptor and estradiol [E2] is the physiological ligand for vertebrate ERs, the identity of the ancestral ligand(s) for the ER remains unknown. Here, using an analysis of crystal structures of human ER[alpha] with E2 and other chemicals and 3D models of human ER[alpha] with 27-hydroxycholesterol and 5-androsten-3[beta],17[beta]-diol, we propose that one or more [DELTA]5...
Tipo: Manuscript Palavras-chave: Cancer; Developmental Biology; Ecology; Genetics & Genomics; Pharmacology; Bioinformatics; Earth & Environment; Evolutionary Biology.
Ano: 2011 URL: http://precedings.nature.com/documents/5777/version/1
Imagem não selecionada

Imprime registro no formato completo
Motif analysis of amphioxus, lamprey and invertebrate estrogen receptors and amphioxus and human estrogen-related receptors: Towards a better understanding of estrogen receptor evolution Nature Precedings
Michael E. Baker; Charlie Chandsawangbhuwana.
*Background.* The origins of steroid-dependent regulation of the vertebrate estrogen receptor (ER) are poorly understood. Genes with statistically significant sequence similarity to vertebrate ERs have been found in lamprey, a basal vertebrate, and amphioxus, a basal chordate. Motif analysis of these sequences provides an opportunity to investigate early events in the evolution of the ER.
*Results.* We used artificial intelligence-based software to construct twelve motifs specific to the estrogen-binding domain of ER[alpha] and ER[beta] in land vertebrates and teleosts. We mapped these ER-specific motifs onto the sequences of lamprey, amphioxus, invertebrate and selected vertebrate ERs and amphioxus and human estrogen-related receptor...
Tipo: Manuscript Palavras-chave: Cancer; Developmental Biology; Ecology; Bioinformatics.
Ano: 2008 URL: http://precedings.nature.com/documents/1542/version/1
Imagem não selecionada

Imprime registro no formato completo
Motif analysis of amphioxus, lamprey and invertebrate estrogen receptors and amphioxus and human estrogen-related receptors: Towards a better understanding of estrogen receptor evolution Nature Precedings
Michael E. Baker; Charlie Chandsawangbhuwana.
*Background.* The origins of steroid-dependent regulation of the vertebrate estrogen receptor (ER) are poorly understood. Genes with statistically significant sequence similarity to vertebrate ERs have been found in lamprey, a basal vertebrate, and amphioxus, a basal chordate. Motif analysis of these sequences provides an opportunity to investigate early events in the evolution of the ER.
*Results.* We used artificial intelligence-based software to construct twelve motifs specific to the estrogen-binding domain of ER[alpha] and ER[beta] in land vertebrates and teleosts. We mapped these ER-specific motifs onto the sequences of lamprey, amphioxus, invertebrate and selected vertebrate ERs and amphioxus, Ciona and human estrogen-related...
Tipo: Manuscript Palavras-chave: Cancer; Developmental Biology; Ecology; Evolutionary Biology.
Ano: 2008 URL: http://precedings.nature.com/documents/1542/version/2
Imagem não selecionada

Imprime registro no formato completo
Origin and diversification of steroids: Co-evolution of enzymes and nuclear receptors Nature Precedings
Michael E. Baker.
Recent sequencing of amphioxus and sea urchin genomes has provided important data for understanding the origins of enzymes that synthesize adrenal and sex steroids and the receptors that mediate physiological response to these vertebrate steroids. Phylogenetic analyses reveal that CYP11A and CYP19, which are involved in the synthesis of adrenal and sex steroids, first appear in the common ancestor of amphioxus and vertebrates. This correlates with recent evidence for the first appearance in amphioxus of receptors with close similarity to vertebrate steroid receptors. Other CYP450 enzymes involved in steroid synthesis can be traced back to invertebrates, in which they have at least two functions: detoxifying xenobiotics and catalyzing the synthesis of...
Tipo: Manuscript Palavras-chave: Developmental Biology; Bioinformatics; Evolutionary Biology.
Ano: 2010 URL: http://precedings.nature.com/documents/4674/version/1
Imagem não selecionada

Imprime registro no formato completo
Trichoplax, the simplest known animal, contains an estrogen-related receptor but no estrogen receptor: Implications for estrogen receptor evolution Nature Precedings
Michael E. Baker.
Although, as their names imply, estrogen receptors [ERs] and estrogen-related receptors [ERRs] are related transcription factors, their evolutionary relationships to each other are not fully understood. To elucidate the origins and evolution of ERs and ERRs, we searched for their orthologs in the recently sequenced genome of _Trichoplax_, the simplest known animal, and in the genomes of three lophotrochozoans: _Capitella_, an annelid worm, _Helobdella robusta_, a leech, and _Lottia gigantea_, a snail. BLAST searches found an ERR in _Trichoplax_, but no ER. BLAST searches also found ERRs in all three lophotrochozoans and invertebrate-like ERs in _Capitella_ and _Lottia_, but not in _Helobdella_. Unexpectedly we find that the _Capitella_ ER sequence is...
Tipo: Manuscript Palavras-chave: Developmental Biology; Ecology; Evolutionary Biology.
Ano: 2008 URL: http://precedings.nature.com/documents/2170/version/1
Imagem não selecionada

Imprime registro no formato completo
Trichoplax, the simplest known animal, contains an estrogen-related receptor: Implications for the evolution of vertebrate and invertebrate estrogen receptors Nature Precedings
Michael E. Baker.
Although, as their names imply, vertebrate and invertebrate estrogen receptors [ERs] and estrogen-related receptors [ERRs] are related transcription factors, their evolutionary relationships to each other are not fully understood. We searched recently sequenced genome of _Trichoplax_, the simplest known animal, and genomes from three lophotrochozoans: _Capitella_, a worm, _Helobdella robusta_, a leech, and _Lottia gigantea_, a snail, to elucidate the origins and evolution of ERs and ERRs. BLAST found an ERR in _Trichoplax_, but no ER. BLAST searches of the lophotrochozaons found ERRs in all three and invertebrate ERs in _Capitella_ and _Lottia_, but not in _Helobdella_. These database searches and a phylogenetic analyses indicate that invertebrate ERs...
Tipo: Manuscript Palavras-chave: Developmental Biology; Ecology; Evolutionary Biology.
Ano: 2008 URL: http://precedings.nature.com/documents/1863/version/1
Registros recuperados: 15
Primeira ... 1 ... Última
 

Empresa Brasileira de Pesquisa Agropecuária - Embrapa
Todos os direitos reservados, conforme Lei n° 9.610
Política de Privacidade
Área restrita

Embrapa
Parque Estação Biológica - PqEB s/n°
Brasília, DF - Brasil - CEP 70770-901
Fone: (61) 3448-4433 - Fax: (61) 3448-4890 / 3448-4891 SAC: https://www.embrapa.br/fale-conosco

Valid HTML 4.01 Transitional