Repression domain of the yeast global repressor Tup1 interacts directly with histones H3 and H4.

  1. D G Edmondson,
  2. M M Smith, and
  3. S Y Roth
  1. Department of Biochemistry and Molecular Biology, University of Texas M.D. Anderson Cancer Center, Houston 77030, USA.

Abstract

Repression of yeast a cell-specific genes by the global repressor Ssn6/Tup1 has been linked to a specific organization of chromatin. We report here that Tup1 directly interacts with the amino-terminal tails of histones H3 and H4, providing a molecular basis for this connection. This interaction appears to be required for Tup1 function because amino-terminal mutations in H3 and H4 that weaken interactions with Tup1 cause derepression of both a cell-specific and DNA damage-inducible genes. Moreover, the Tup1 histone-binding domain coincides with the previously defined Tup1 repression domain. Tup1/histone interactions are negatively influenced by high levels of histone acetylation, suggesting a mechanism whereby the organization of chromatin may be modulated in response to changing environmental signals.

Footnotes

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