A Tale of Histone's Tails

Abstract

The DNA of all eukaryotes is packaged into chromatin, which is composed largely of histone proteins. Covalent modifications of the tails of these proteins play an important role in both chromosome organization and the specific regulation of individual genes (see the Review by Jenuwein and Allis ). Noma et al. show that methylation of Lys 4 in the amino-terminal tail of histone H3 is specific to euchromatic domains (where genes are generally active) and methylation of H3 Lys 9 is specific to heterochromatic domains of chromatin (where genes are generally inactive). Inverted repeats flanking the heterochromatin act as boundary elements and prevent its spread into the surrounding euchromatic regions. At the level of individual genes, Lo et al. show that phosphorylation of Ser 10 on histone H3 by Snf1 kinase facilitates acetylation of Lys 14 by Gcn5 (but not vice versa), and that both are needed for the activation of the INO1 gene in vivo. T. Jenuwein, C. D. Allis, Translating the histone code. Science 293 , 1074-1080 (2001). [Abstract] [Full Text] K-i. Noma, C. D. Allis, S. I. S. Grewal, Transitions in distinct histone H3 methylation patterns at the heterochromatin domain boundaries. Science 293 , 1150-1155 (2001). [Abstract] [Full Text] W.-S. Lo, L. Duggan, N. C. T. Emre, R. Belotserkovskya, W. S. Lane, R. Shiekhattar, S. L. Berger, Snf1--A histone kinase that works in concert with the histone acetyltransferase Gcn5 to regulate transcription. Science 293 , 1142-1146 (2001). [Abstract] [Full Text]