Just five years ago, Rett Syndrome was tracked to mutations in a gene on the X chromosome, MECP2. But how this gene, not previously associated with the brain or nervous system, could cause a neurological developmental disorder remained a puzzle.
Now, a team of scientists with the U.S. Department of Energy's Lawrence Berkeley National Laboratory has developed new methods and overturned mistaken assumptions to discover how the product of this gene, the protein MeCP2, can remodel chromatin, the material that makes up chromosomes. For the first time a human disease -- Rett Syndrome, the first identified epigenetic disease -- has been linked to specific defects in the three-dimensional folding of chromatin.
The research was supervised by Terumi Kohwi-Shigematsu, a biochemist with Berkeley Lab's Life Sciences Division; it reveals how mutated MeCP2 protein represses genes, and identifies some of the most important of those genes. Kohwi-Shigematsu and her colleagues, Shin-ichi Horike, Shutao Cai, Masaru Miyano, and Jan-Fang Chen, report their results in advanced online publication of the January issue of Nature Genetics. [See http://origin.www.nature.com/cgi-taf/DynaPage.taf?file=/ng/journal/vaop/ncurrent/index.html]
How MECP2 works
So-called CpG "islands" are found at the promoter regions of many housekeeping genes, which code for proteins essential to cell function. They contain high densities of cytosin
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Contact: Paul Preuss
paul_preuss@lbl.gov
510-486-6249
DOE/Lawrence Berkeley National Laboratory
19-Dec-2004