A Histone Mutant Reproduces the Phenotype Caused by Loss of Histone-Modifying Factor Polycomb

Abstract

Genetic Epigenetics Posttranslational modifications of histone proteins have been implicated in the regulation of gene transcription in organisms ranging from yeast to humans. However, epigenetic regulators can modify multiple proteins. By mutating specific histone sites in Drosophila , Pengelly et al. (p. 698 ) demonstrate that mutation of lysine 27 of histone H3 causes the same transcriptional defects as those observed in mutants lacking the methyltransferase PRC2 that modifies this H3 residue. These results demonstrate the functional importance of H3-K27 methylation in Polycomb repression. Furthermore, this genetic approach may be applied to investigating numerous other metazoan-specific histone modifications.