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Metamorphic T 3 ‐response genes have specific co‐regulator requirements
Author(s) -
Havis Emmanuelle,
Sachs Laurent M,
Demeneix Barbara A
Publication year - 2003
Publication title -
embo reports
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 4.584
H-Index - 184
eISSN - 1469-3178
pISSN - 1469-221X
DOI - 10.1038/sj.embor.embor908
Subject(s) - biology , regulator , yy1 , coactivator , transcriptional regulation , repressor , thyroid hormone receptor , gene , promoter , transcription factor , regulation of gene expression , nuclear receptor , histone , chromatin , microbiology and biotechnology , genetics , gene expression
Thyroid hormone receptors (TRs) have several regulatory functions in vertebrates. In the absence of thyroid hormone (T 3 ; triiodothyronine), apo‐TRs associate with co‐repressors to repress transcription, whereas in the presence of T 3 , holo‐TRs engage transcriptional coactivators. Although many studies have addressed the molecular mechanisms of T 3 action, it is not known how specific physiological responses arise. We used T 3 ‐dependent amphibian metamorphosis to analyse how TRs interact with particular co‐regulators to differentially regulate gene expression during development. Using chromatin immunoprecipitation to study tissue from pre‐metamorphic tad‐poles, we found that TRs are physically associated with T 3 ‐responsive promoters, whether or not T 3 is present. Addition of T 3 results in histone H4 acetylation specifically on T 3 ‐response genes. Most importantly, we show that individual T 3 ‐response genes have distinct co‐regulator requirements, the T 3 ‐dependent co‐repressor‐to‐coactivator switch being gene‐specific for both co‐regulator categories.