Role of conserved hydrophobic amino acids in androgen receptor AF-1 function

Russell Betney, Iain Joseph McEwan

Research output: Contribution to journalArticle

26 Citations (Scopus)

Abstract

The intracellular androgen receptor (AR) is a ligand-activated transcription factor. Upon binding the steroids testosterone or dihydrotestosterone, the activated receptor translocates to the nucleus, binds to specific DNA response elements and interacts with the transcription machinery in order to regulate gene transcription. In the present study, we have described a highly conserved region (amino acids 224-258) within the AR AF-1 domain and have investigated the role of conserved bulky hydrophobic residues in gene regulation. Mutating pairs of residues (I229A/L236A; V240A/V242A; L251A/L254A) reduced transactivation activity by 25-40%. Mutating residues M244, L246 and V248 to alanines had a more dramatic affect on receptor activity, disrupting activity by at least 60%. The latter mutations also disrupted binding to the RNA polymerase-associated protein 74 subunit of the general transcription factor TFIIF The protein conformation and stability of the mutant polypeptide in vitro was not significantly different from the wild type. None of the mutations tested disrupted binding of the AF-1 domain with the coactivator protein steroid receptor coactivator-la. Thus we have concluded that conserved hydrophobic residues are important for receptor-dependent gene transcription and that M244, L246 and V248 are part of the binding interface for TFIIF.

Original languageEnglish
Pages (from-to)427-439
Number of pages12
JournalJournal of Molecular Endocrinology
Volume31
Issue number3
DOIs
Publication statusPublished - 2003

Keywords

  • TRANSCRIPTIONAL ACTIVATION DOMAIN
  • HUMAN GLUCOCORTICOID-RECEPTOR
  • CRITICAL STRUCTURAL ELEMENTS
  • PROTEIN-PROTEIN INTERACTIONS
  • N-TERMINAL DOMAIN
  • TRANSACTIVATION DOMAIN
  • ESTROGEN-RECEPTOR
  • BINDING PROTEIN
  • DISTINCT REGIONS
  • FACTOR TFIIF

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