http://precedings.nature.com/tags/nuclear%20receptors Recently posted documents tagged with 'nuclear receptors' Nature Publishing Group en Nature Precedings http://precedings.nature.com/images/header_logo.gif http://precedings.nature.com http://precedings.nature.com/documents/3374/version/1 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 Bilaterian lineages, and that steroidogenic cytochrome P450 enzymes descended from those that detoxify xenobiotics. http://precedings.nature.com/documents/3374/version/1 Fri, 26 Jun 2009 15:22:07 UTC Independent elaboration of steroid hormone signaling pathways in Metazoans hdl:10101/npre.2009.3374.1 2009-06-26 Michael E. Baker Nature Precedings 2009-06-26T15:22:07Z Manuscript Cancer Developmental Biology Bioinformatics Earth & Environment Evolutionary Biology http://creativecommons.org/licenses/by/3.0/ http://precedings.nature.com/documents/3316/version/1 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 ERα are not conserved in the SR, which can explain the low affinity of estradiol for the SR. These differences between the SR and ERα in the steroid-binding domain are sufficient to suggest that another steroid is the physiological regulator of the SR. The 3D model predicts that mutation of Glu-346 to Gln will increase the affinity of testosterone for amphioxus SR and elucidate the evolution of steroid binding to nuclear receptors. http://precedings.nature.com/documents/3316/version/1 Fri, 05 Jun 2009 20:00:44 UTC 3D model of amphioxus steroid receptor complexed with estradiol hdl:10101/npre.2009.3316.1 2009-06-05 Michael E. Baker Nature Precedings 2009-06-05T20:00:44Z Manuscript Cancer Developmental Biology Bioinformatics Evolutionary Biology http://creativecommons.org/licenses/by/3.0/ http://precedings.nature.com/documents/2170/version/1 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 closest to ERβ, unlike the other invertebrate ER sequences, which are closest to ERα. Our database searches and phylogenetic analysis indicate that invertebrate ERs evolved in a lophotrochozoan and steroid-binding ERs evolved in a deuterostome. http://precedings.nature.com/documents/2170/version/1 Wed, 13 Aug 2008 09:09:40 UTC Trichoplax, the simplest known animal, contains an estrogen-related receptor but no estrogen receptor: Implications for estrogen receptor evolution hdl:10101/npre.2008.2170.1 2008-08-13 Michael E. Baker Nature Precedings 2008-08-13T09:09:40Z Manuscript Developmental Biology Ecology Evolutionary Biology http://creativecommons.org/licenses/by/3.0/ http://precedings.nature.com/documents/1863/version/1 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 arose in a protostome, and vertebrate ERs arose later in deuterostome. http://precedings.nature.com/documents/1863/version/1 Tue, 06 May 2008 22:32:29 UTC Trichoplax, the simplest known animal, contains an estrogen-related receptor: Implications for the evolution of vertebrate and invertebrate estrogen receptors hdl:10101/npre.2008.1863.1 2008-05-06 Michael E. Baker Nature Precedings 2008-05-06T22:32:29Z Manuscript Developmental Biology Ecology Evolutionary Biology http://creativecommons.org/licenses/by/3.0/