The androgen receptor interacts with multiple regions of the large subunit of general transcription factor TFIIF.
The androgen receptor (AR) is a ligand-activated transcription factor that regulates genes important for male development and reproductive function. The main determinants for the transactivation function lie within the structurally distinct amino-terminal domain. Previously we identified an interaction between the AR-transactivation domain (amino acids 142-485) and the general transcription factor TFIIF (McEwan, I. J., and Gustafsson, J.-A. (1997) Proc. Natl. Acad. Sci. U. S. A. 94, 8485-8490). We have now mapped the binding sites for the AR-transactivation domain within the RAP74 subunit of TFIIF. Both the amino-terminal 136 amino acids and the carboxyl-terminal 155 amino acids of RAP74 interacted with the AR-transactivation domain and were able to rescue basal transcription after squelching by the AR polypeptide. Competition experiments demonstrated that the AR could interact with the holo-TFIIF protein and that the carboxyl terminus of RAP74 represented the principal receptor-binding site. Point mutations within AR-transactivation domain distinguished the binding sites for RAP74 and the p160 coactivator SRC-1a and identified a single copy of a six amino acid repeat motif as being important for RAP74 binding. These data indicate that the AR-transactivation domain can potentially make multiple protein-protein interactions with coactivators and components of the general transcriptional machinery in order to regulate target gene expression.
Department of Molecular and Cell Biology, Institute of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen AB25 2ZD, Scotland, UK.
James
J
Reid
Ian
I
Murray
Kate
K
Watt
Russell
R
Betney
Iain J
IJ
McEwan
D001483:Base Sequence; D001665:Binding Sites; D017931:DNA Primers; D016297:Mutagenesis, Site-Directed; D011944:Receptors, Androgen / Q000235:genetics / Q000378:metabolism*; D019473:Transcription Factors, TFII / Q000737:chemistry / Q000378:metabolism*
D017931:DNA Primers; D011944:Receptors, Androgen; D019473:Transcription Factors, TFII; C056604:transcription factor TFIIF