The Regulation of Gene Activity by Histones and the Histone Deacetylase RPD3 (original) (raw)

1. N. SUKA,
2. A.A. CARMEN,
3. S.E. RUNDLETT, and
4. M. GRUNSTEIN
5. Department of Biological Chemistry, UCLA School of Medicine and the Molecular Biology Institute, University of California, Los Angeles, California 90095

Excerpt

In yeast, upstream activator sequences (UASs) are usually in nuclease-hypersensitive regions believed to be devoid of nucleosomes even prior to the binding of the activator proteins. This may result from the constitutivebinding of factors that exclude core particles. This exclusion positions adjacent nucleosomes that repress nearbyTATA elements and basal transcription. The mechanismby which repression occurs and is alleviated has recentlyreceived considerable attention and involves, in certaincases, the deacetylation and acetylation of the histoneamino termini. This undoubtedly results in a structuralchange in chromatin that enables gene regulation. However, genes are differentially sensitive to regulation by histones. It is probable that certain genes utilize proteinsthat function independently of histones to mediate repression and activation, whereas others use histone modification as the dominant form of regulation...