Interaction of the human androgen receptor transactivation function with the general transcription factor TFIIF

Interaction of the human androgen receptor transactivation function with the general transcription factor TFIIF

Iain J. McEwan* and
Jan-Åke Gustafsson

Department of Biosciences, Novum, Karolinska Institute, S-141 57 Huddinge, Sweden

Abstract

The human androgen receptor (AR) is a ligand-activated transcription factor that regulates genes important for male sexual differentiation and development. To better understand the role of the receptor as a transcription factor we have studied the mechanism of action of the N-terminal transactivation function. In a protein–protein interaction assay the AR N terminus (amino acids 142–485) selectively bound to the basal transcription factors TFIIF and the TATA-box-binding protein (TBP). Reconstitution of the transactivation activity in vitro revealed that AR_142–485 fused to the LexA protein DNA-binding domain was competent to activate a reporter gene in the presence of a competing DNA template lacking LexA binding sites. Furthermore, consistent with direct interaction with basal transcription factors, addition of recombinant TFIIF relieved squelching of basal transcription by AR_142–485. Taken together these results suggest that one mechanism of transcriptional activation by the AR involves binding to TFIIF and recruitment of the transcriptional machinery.

Footnotes

↵ * To whom reprint requests should be addressed at present address: Department of Molecular and Cell Biology, University of Aberdeen, Institute of Medical Sciences, Foresterhill, Aberdeen AB25 2ZD, Scotland, United Kingdom. e-mail: iain.mcewan{at}abdn.ac.uk.
Elwood V. Jensen, University of Hamburg, Hamburg, Germany
ABBREVIATIONS:

AR,

androgen receptor;

AR142–485,

AR residues 142–485;

LexADBD,

LexA DNA-binding domain (residues 1–87);

TBP,

TATA-box-binding protein;

SRF,

serum response factor