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DNA methylation specifies chromosomal localization of MeCP2
1Institute of Cell and Molecular Biology, University of Edinburgh, United Kingdom.
Molecular and Cellular Biology
|January 1, 1996
Summary
Methyl-CpG-binding protein 2 (MeCP2) localizes to heterochromatin, a function dependent on DNA methylation. This protein acts as a key mediator for DNA methylation
Area of Science:
- Molecular Biology
- Epigenetics
- Genetics
Background:
- Methyl-CpG-binding protein 2 (MeCP2) is a chromosomal protein found in mouse cell centromeric heterochromatin.
- In vitro studies show MeCP2 binds preferentially to DNA with symmetrically methylated CpG sites.
Purpose of the Study:
- To determine if the heterochromatic localization of MeCP2 is dependent on DNA methylation.
- To investigate the role of the methyl-CpG binding domain in MeCP2 localization.
Main Methods:
- Transient expression of MeCP2-LacZ fusion proteins in cultured cells.
- Comparison of MeCP2 localization in wild-type and mutant cells with varying DNA methylation levels.
- Analysis of MeCP2 deletions to identify functional domains for heterochromatin targeting.
Main Results:
- MeCP2 was efficiently targeted to heterochromatin in wild-type cells.
- MeCP2 localization was inefficient in mutant cells with low genomic DNA methylation.
- The 85-amino-acid methyl-CpG binding domain was essential for heterochromatin localization, while other parts of the protein were not required.
Conclusions:
- MeCP2 functions as a methyl-CpG-binding protein in vivo.
- MeCP2's heterochromatic localization is dependent on DNA methylation.
- MeCP2 is likely a major mediator of the downstream effects of DNA methylation.