Chromosomal gradient of histone acetylation established by Sas2p and Sir2p functions as a shield against gene silencing.
Genes located in chromosomal regions near telomeres are transcriptionally silent, whereas those located in regions away from telomeres are not. Here we show that there is a gradient of acetylation of histone H4 at lysine 16 (H4-Lys16) along a yeast chromosome; this gradient ranges from a hypoacetylated state in regions near the telomere to a hyperacetylated state in more distant regions. The hyperacetylation is regulated by Sas2p, a member of the MYST-type family of histone acetylases, whereas hypoacetylation is under the control of Sir2p, a histone deacetylase. Loss of hyperacetylation is accompanied by an increase in localization of the telomere protein Sir3p and the inactivation of gene expression in telomere-distal regions. Thus, the Sas2p and Sir2p function in concert to regulate transcription in yeast, by acetylating and deacetylating H4-Lys16 in a mechanism that may be common to all eukaryotes.[1]References
- Chromosomal gradient of histone acetylation established by Sas2p and Sir2p functions as a shield against gene silencing. Kimura, A., Umehara, T., Horikoshi, M. Nat. Genet. (2002) [Pubmed]
Annotations and hyperlinks in this abstract are from individual authors of WikiGenes or automatically generated by the WikiGenes Data Mining Engine. The abstract is from MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.About WikiGenesOpen Access LicencePrivacy PolicyTerms of Useapsburg
