Transcription activator-coactivator interactions and the genome-wide role of coactivator TFIID.

  • Datum: 10.10.2017
  • Uhrzeit: 13:00 - 14:00
  • Vortragende(r): Steven Hahn
  • Fred Hutchinson Cancer Research Center, Seattle
  • Ort: Max-Planck-Institut für biophysikalische Chemie (MPIBPC)
  • Raum: Tower IV, Seminar Room, 2nd Floor
  • Gastgeber: Dr. Johannes Söding
  • Kontakt: soeding@mpibpc.mpg.de
Abstract:
Efficient transcription activation by yeast Gcn4 requires Gcn4’s tandem activation domains (ADs) and multiple activator-binding domains (ABDs) on Med15, a Mediator subunit. Here, we investigated whether this large Gcn4-Med15 complex locks into a unique orientation with a specific protein-protein interface. In contrast to this model, we find that Gcn4 binds Med15 in a dynamic fuzzy “free-for-all” where each Gcn4 AD interacts with each of four Med5 ABDs. This fuzzy complex seems designed to work with the unique properties of the eukaryotic transcription system to regulate gene expression.
Also discussed will be genome-wide studies to examine the requirements for the coactivators TFIID and SAGA. We find that both complexes significantly contribute to transcription of nearly all yeast genes, in contrast to earlier predictions. Our findings suggest that differences in promoter function previously attributed to different coactivator requirements are due to other promoter properties.
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