Forster resonance energy transfer (FRET) detection of protein interaction in living cells is commonly measured following the expression of interacting proteins genetically fused to the cyan (CFP) and yellow (YFP) derivatives of the Aequorea victoria fluorescent protein (FP). These FPs can dimerize at mM concentrations, which may introduce artifacts into the measurement of interaction between proteins that are fused with the FPs. Here, FRET analysis of the interaction between estrogen receptors (alpha isoform, ERalpha) labeled with "wild-type" CFP and YFP is compared with that of ERalpha labeled with "monomeric" A206K mutants of CFP and YFP. The intracellular equilibrium dissociation constant for the hormone-induced ERalpha-ERalpha interaction is similar for ERalpha labeled with wild-type or monomeric FPs. However, the measurement of energy transfer measured for ERalpha-ERalpha interaction in each cell is less consistent with the monomeric FPs. Thus, dimerization of the FPs does not affect the kinetics of ERalpha-ERalpha interaction but, when brought close together via ERalpha-ERalpha interaction, FP dimerization modestly improves FRET measurement.
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http://dx.doi.org/10.1117/1.2940366 | DOI Listing |
Front Oncol
May 2020
Department of Breast Surgery, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, China.
Dysregulation of ESR1 accounts for endocrine therapy resistance and metastasis of ERα positive breast cancer. However, the underlying molecular mechanism of ESR1 in ERα positive breast cancer remains insufficiency. Notably, to date, a comprehensive miRNA-mRNA regulatory network involved in modulation of ESR1 in development and progression of ERα positive breast cancer is still not established.
View Article and Find Full Text PDFInt J Cancer
October 2019
Instituto de Biología y Medicina Experimental, IByME-CONICET, Buenos Aires, Argentina.
Progression to hormone-independent growth leading to endocrine therapy resistance occurs in a high proportion of patients with estrogen receptor alpha (ERα) and progesterone receptors (PR) positive breast cancer. We and others have previously shown that estrogen- and progestin-induced tumor growth requires ERα and PR interaction at their target genes. Here, we show that fibroblast growth factor 2 (FGF2)-induces cell proliferation and tumor growth through hormone-independent ERα and PR activation and their interaction at the MYC enhancer and proximal promoter.
View Article and Find Full Text PDFEndocrinology
June 2016
INSERM Unité 1048 (A.V., M.C.V., M.B., M.A., M.G., F.L., J.F.A., C.F.), I2MC, University of Toulouse 3, F-31432 Toulouse, France; Unité Mixte de Recherche 1132 (E.H., M.C.-S.), Bone and Cartilage Biology, University of Paris 7, F-75006 Paris, France; and Centre for Bone and Arthritis Research (C.O.), Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, SE-413 45 Gothenburg, Sweden.
Estrogen receptor-α (ERα) acts primarily in the nucleus as a transcription factor involving two activation functions, AF1 and AF2, but it can also induce membrane-initiated steroid signaling (MISS) through the modulation of various kinase activities and/or secondary messenger levels. Previous work has demonstrated that nuclear ERα is required for the protective effect of the estrogen 17β-estradiol (E2), whereas the selective activation of ERαMISS is sufficient to confer protection in cortical but not cancellous bone. The aim of this study was to define whether ERαMISS is necessary for the beneficial actions of chronic E2 exposure on bone.
View Article and Find Full Text PDFMol Cell Endocrinol
March 2015
Program in Reproductive and Adult Endocrinology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, 10 CRC, Room 1E-3140, 10 Center Drive, MSC 1109, Bethesda, MD 20892-1109, USA. Electronic address:
17β-estradiol (E2), a key participant on the initiation of the LH surge, exerts both positive and negative feedback on GnRH neurons. We sought to investigate potential interactions between estrogen receptors alpha (ERα) and beta (ERβ) and gonadotropin releasing hormone receptor (GnRH-R) in GT1-7 cells. Radioligand binding studies demonstrated a significant decrease in saturation E2 binding in cells treated with GnRH agonist.
View Article and Find Full Text PDFEndocrinology
December 2013
Department of Comparative Biosciences, 2015 Linden Drive, University of Wisconsin-Madison, Madison, WI 53706.
Resistance of estrogen receptor positive (ERα+) breast cancers to antiestrogens is a major factor in the mortality of this disease. Although activation of ERα in the absence of ligand is hypothesized to contribute to this resistance, the potency of this mechanism in vivo is not clear. Epidemiologic studies have strongly linked prolactin (PRL) to both development of ERα+ breast cancer and resistance to endocrine therapies.
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