The response of eukaryotic cells to double-strand breaks in genomic DNA includes the sequestration of many factors into nuclear foci. Recently it has been reported that a member of the histone H2A family, H2AX, becomes extensively phosphorylated within 1-3 minutes of DNA damage and forms foci at break sites.
Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892-0540, USA.
