Carbohydrates induce mono-ubiquitination of H2B in yeast

Histone modifications have emerged to be a major regulatory mechanism for gene expression ( 1 - 4). However, it is not clear how histone modifications are physiologically regulated. Here, we show that mono-ubiquitinated H2B at lysine 123 (uH2B) in the yeast ( Saccharomyces cerevisiae) is present in exponential phase and absent in stationary phase. A wide array of carbohydrates or sugars, including glucose, fructose, mannose, and sucrose, are capable of inducing uH2B in stationary phase yeast. In contrast, non-metabolic glucose analogs are defective in inducing uH2B. Furthermore, uH2B induction is inhibited by iodoacetate, an inhibitor of glyceraldehyde-3- phosphate dehydrogenase in glycolysis. Moreover, uH2B induction is markedly impaired in yeast mutants, in which glycolytic genes are deleted. These data indicate that glycolysis is required for the carbohydrate-induced mono-ubiquitination of H2B at lysine 123. Therefore, our study reveals a novel paradigm of metabolic regulation of histone modifications.