In vitro regulation of reporter gene transcription by the androgen receptor AF1 domain.
The androgen receptor (AR) is a ligand-activated transcription factor that regulates gene expression in response to the steroids testosterone and dihydrotestosterone. AR-dependent gene expression is likely to play an important role in a number of receptor-associated disorders, such as prostate cancer, spinal bulbar muscular atrophy, male type baldness and hirsutism. The AR contains two transactivation domains, termed AF1 (activation function 1) located in the N-terminus and AF2 (activation function 2) in the C-terminal ligand-binding domain. AF2 exhibits weak transcriptional activity, whereas AF1 is a strong regulator of transcription. Transcriptional regulation by AF1 is thought to be modulated by a number of proteins that interact with this region, and by post-translational modifications. Our focus is on the N-terminal-interacting proteins and their regulation of transcription via interaction with the receptor. To better understand the mechanism of AR-AF1 action, we have reconstituted AR activity in HeLa nuclear extracts using a unique dual reporter gene assay. Multiple LexA-binding sites in the promoter allow transcription to be driven by a recombinant AR-AF1-Lex fusion protein. The findings from initial experiments suggest an increase in transcription initiation and elongation rates by AR-AF1-Lex. The role of protein-protein interactions involving co-activators and basal transcription factors and AR-AF1 activity are discussed.
Choudhry
M A
MA
School of Medical Sciences, IMS Building, University of Aberdeen, Foresterhill, Aberdeen AB25 2ZD, Scotland, UK. m.a.choudhry@abdn.ac.uk
McEwan
I J
IJ
D001483:Base Sequence; D001665:Binding Sites; D002474:Cell-Free System; D005786:Gene Expression Regulation; D006801:Humans; D008969:Molecular Sequence Data; D011944:Receptors, Androgen / Q000737:chemistry / Q000502:physiology*; D019473:Transcription Factors, TFII / Q000378:metabolism; D014158:Transcription, Genetic
D011944:Receptors, Androgen; D019473:Transcription Factors, TFII; C056604:transcription factor TFIIF