Histone demethylation and androgen-dependent transcription.

Covalent modifications of histones play important roles in the regulation of chromatin dynamics and gene activity. Until recently, it was believed that methyl groups could not be removed from histones; as such, the discovery of the first demethylases opens a novel era in understanding how chromatin dynamic is regulated and shows that active demethylation is linked to both transcriptional repression and activation. During androgen-dependent gene activation, specific demethylases are involved in the control of gene expression. These new findings represent a milestone in elucidating the function of demethylases in gene expression. Furthermore, they show that active demethylation of repressive histone marks is a hallmark in the control of specific gene expression.