An. Hollenberg et al., FUNCTION OF NUCLEAR CO-REPRESSOR PROTEIN ON THYROID-HORMONE RESPONSE ELEMENTS IS REGULATED BY THE RECEPTOR A B DOMAIN/, The Journal of biological chemistry, 271(45), 1996, pp. 28516-28520
Recently, a family of nuclear co-repressor proteins (TRACs) have been
identified that interact with thyroid hormone (TR) and retinoic acid r
eceptors to mediate Ligand-independent repression of gene transcriptio
n. In this report, we have cloned and characterized a human TRAC, whic
h when expressed as a truncated protein lacking its repressing domains
, can abolish endogenous cellular TRAC activity. Use of this inhibitor
has uncovered a differential function of TRACs on negative versus pos
itive thyroid hormone response elements and has demonstrated the impor
tance of the TR A/B domain in modulating TRAC function. Thus, isoform-
specific functions of the TR may be mediated by their functional inter
action with co-repressor proteins.