http://precedings.nature.com/tags/estrogen%20receptor Recently posted documents tagged with 'estrogen receptor' Nature Publishing Group en Nature Precedings http://precedings.nature.com/images/header_logo.gif http://precedings.nature.com http://precedings.nature.com/documents/2834/version/1 Breast cancer is known to be a hormone-dependent disease, and estrogens through an interaction with estrogen receptor (ER) enhance the proliferative and metastatic activity of breast tumor cells. Here we show a critical role of transactivation of BIG3, brefeldin A-inhibited guanine nucleotide-exchange protein 3, in activation of the estrogen/ER signaling in breast cancer cells. Knocking-down of BIG3 expression with small-interfering RNA (siRNA) drastically suppressed the growth of breast cancer cells. Subsequent co-immunoprecipitation and immunoblotting assays revealed an interaction of BIG3 with prohibitin 2/repressor of estrogen receptor activity (PHB2/REA). When BIG3 was absent, stimulation of estradiol caused the translocation of PHB2/REA to the nucleus, enhanced the interaction of PHB2/REA and ERα, and resulted in suppression of the ERα; transcriptional activity. On the other hand, when BIG3 was present, BIG3 trapped PHB2/REA in cytoplasm and inhibited its nuclear translocation, and caused enhancement of ERα; transcriptional activity. Our results imply that BIG3 overexpression is one of the important mechanisms causing the activation of the estrogen/ERα; signaling pathway in the hormone-related growth of breast cancer cells. http://precedings.nature.com/documents/2834/version/1 Fri, 30 Jan 2009 17:42:31 UTC Activation of an Estrogen/ Estrogen Receptor Signaling by BIG3 Through Its Inhibitory Effect on Nuclear Transport of PHB2/REA in Breast Cancer hdl:10101/npre.2009.2834.1 2009-01-30 Toyomasa Katagiri Nature Precedings 2009-01-30T17:42:31Z Manuscript Cancer Genetics & Genomics 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/