A protein previously implicated in mental retardation has now been shown to influence gene expression by modifying histones. The finding, appearing in a paper published online by Nature, may shed light on a molecular mechanism behind neurological disorders.
Histones are the major proteins that package DNA into chromatin to form chromosomes. Enzymes can add or remove modifications such as methyl groups to these histones and in turn influence DNA-based events such as gene transcription. Yujiang Shi and colleagues have shown that a protein called SMCX (or JARID1C) acts as a demethylating enzyme. The molecule removes tri-methyl groups from histone H3 at lysine residue 4 and can repress transcription of certain neuronal genes.
The gene encoding SMCX is frequently mutated in X-linked mental retardation, in which defects in genes on the X chromosome are inherited. Mutations in SMCX might contribute to disease by impairing regulation of neuronal genes.
Yujiang Shi (Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA)
Jessica Podlaski (Media Relations Coordinator, Brigham and Women's Hospital, Boston, MA, USA)
Abstract available online.
(C) Nature press release.
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