Open AccessUse of Suppressor Mutants To Probe the Function of Estrogen Receptor-p160 Coactivator Interactions
Author(s) -
Ho Yi Mak,
Malcolm G. Parker
Publication year - 2001
Publication title -
molecular and cellular biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.14
H-Index - 327
eISSN - 1067-8824
pISSN - 0270-7306
DOI - 10.1128/mcb.21.13.4379-4390.2001
Subject(s) - coactivator , nuclear receptor coactivator 1 , biology , nuclear receptor coactivator 2 , nuclear receptor , nuclear receptor coactivator 3 , estrogen receptor , transcription factor , estrogen receptor alpha , microbiology and biotechnology , estrogen related receptor gamma , estrogen related receptor alpha , genetics , gene , cancer , breast cancer
Estrogen-dependent recruitment of coactivators by estrogen receptor alpha (ERalpha) represents a crucial step in the transcriptional activation of target genes. However, studies of the function of individual coactivators has been hindered by the presence of endogenous coactivators, many of which are potentially recruited in the presence of agonist via a common mechanism. To circumvent this problem, we have generated second-site suppressor mutations in the nuclear receptor interaction domain of p160 coactivators which rescue their binding to a transcriptionally defective ERalpha that is refractory to wild-type coactivators. Analysis of these altered-specificity receptor-coactivator combinations, in the absence of interference from endogenous coregulators, indicated that estrogen-dependent transcription from reporter genes is critically dependent on direct recruitment of a p160 coactivator in mammalian cells and that the three p160 family members serve functionally redundant roles. Furthermore, our results suggest that such a change-of-specificity mutation may act as a transposable protein-protein interaction module which provides a novel tool with which to dissect the functional roles of other nuclear receptor coregulators at the cellular level.