Mechanistic analysis of estrogen receptor action using dominant negative mutants
type: CreativeWork
description: We have generated and characterized dominant negative mutants of human estrogen receptor, which are mutant forms of ER that are capable of suppressing the activity of wild-type receptor when they are co-expressed in the same cells. These mutants can be divided into two different categories: (1) The non-hormone binding mutants, NHB1 and NHB7, in which the hormone binding region has been mutated making them unable to bind estrogen; (2) the transactivation mutants S554Fs, L540Q and ER1-530, in which amino acids directly involved in ligand-dependent transcriptional activation have been mutated or deleted. Although they are still able to bind estrogen, these ER mutants are no longer able to activate gene transcription. While the non-hormone binding mutants NHB1 and NHB7 are less effective than the transactivation domain mutants in inhibiting the ability of wild-type ER to activate transcription, studies of these mutants have led us to a better understanding of the role of hormone binding in estrogen receptor action. These mutants are able to dimerize and to bind to estrogen response element DNA both in vitro and in vivo, indicating that hormone binding is not a prerequisite for receptor dimerization or DNA binding. We propose that the primary function of the hormone is to convert the receptor to a state in which it is able to activate gene transcription. The three transactivation mutants, S554Fs, L540Q and ER1-530, are the most powerful dominant negative mutants that we have generated. Characterization of these mutants revealed that dimerization with the wild-type ER may play an important role in their ability to act as dominant negative mutants. We demonstrated that all three mutants are able to form heterodimers with the wild-type ER when they are co-expressed in COS cells. Consequently, these heterodimers may be transcriptionally inactive. When the powerful dominant negative mutant, S554Fs, is coexpressed with the wild-type ER, it is able to inhibit the binding of wil…
abstract: We have generated and characterized dominant negative mutants of human estrogen receptor, which are mutant forms of ER that are capable of suppressing the activity of wild-type receptor when they are co-expressed in the same cells. These mutants can be divided into two different categories: (1) The non-hormone binding mutants, NHB1 and NHB7, in which the hormone binding region has been mutated making them unable to bind estrogen; (2) the transactivation mutants S554Fs, L540Q and ER1-530, in which amino acids directly involved in ligand-dependent transcriptional activation have been mutated or deleted. Although they are still able to bind estrogen, these ER mutants are no longer able to activate gene transcription. While the non-hormone binding mutants NHB1 and NHB7 are less effective than the transactivation domain mutants in inhibiting the ability of wild-type ER to activate transcription, studies of these mutants have led us to a better understanding of the role of hormone binding in estrogen receptor action. These mutants are able to dimerize and to bind to estrogen response element DNA both in vitro and in vivo, indicating that hormone binding is not a prerequisite for receptor dimerization or DNA binding. We propose that the primary function of the hormone is to convert the receptor to a state in which it is able to activate gene transcription. The three transactivation mutants, S554Fs, L540Q and ER1-530, are the most powerful dominant negative mutants that we have generated. Characterization of these mutants revealed that dimerization with the wild-type ER may play an important role in their ability to act as dominant negative mutants. We demonstrated that all three mutants are able to form heterodimers with the wild-type ER when they are co-expressed in COS cells. Consequently, these heterodimers may be transcriptionally inactive. When the powerful dominant negative mutant, S554Fs, is coexpressed with the wild-type ER, it is able to inhibit the binding of wil…
author: Zhuang, Yao
language: eng
keywords: Biology, Molecular, Biology, Cell, Chemistry, Biochemistry
date published: 2011-05-07T11:56:30Z
date modified: 2026-07-22T22:25:12Z
provider: University of Illinois - Urbana-Champaign
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: University of Illinois at Urbana-Champaign

PropertyValue
property ID: Handle
value: http://hdl.handle.net/2142/19086