Editing of Imprinting Defects by targeted methylation
The aim of this project is to correct the aberrant DNA methylation in imprinting diseases. For this purpose, so called DNA methyltransferases are used, enzymes which transfer methyl groups to the DNA. These will be targeted by Zincfinger proteins to the DNA sites in the genome where the DNA methylation must be corrected. Zinc finger proteins can be used for this purpose, because their DNA binding specificity can be artificially designed. We will produce zinc finger proteins that bind specifically to the Prader/Willi and Angelman syndrome locus. The binding will be preferentially targeted to the DNA sequences in which the DNA methylation defects occur in patients with imprinting disorders. If targeting to the Prader / Willi and Angelman syndrome locus is not successful, we will also work with the Beckwith / Wiedemann and Silver / Russel syndrome locus. The binding of the zinc finger proteins to the target regions will be verified. For this, a method called chromatin immunoprecipitation will be used, which allows to investigate the binding of proteins to DNA in a genome-wide scale. Afterwards, these zinc finger proteins will be fused with DNA methyltransferases to methylate the target regions and, thereby, correct the methylation defect. Various methods will be tested in order to introduce the Zincfinger DNA - Methyltransferase constructs into cells. Then, the allele specific changes in the DNA methylation will be examined using the resources of the consortium. Upon successful methylation of target regions, allele-specific gene expression of the corresponding imprinted genes will be analyzed.
The project is part of the consortium „Diseases caused by imprinting defects: clinical spectrum and pathogenetic mechanisms“ and it will be supported by the BMBF in the funding program und wird vom BMBF in der Fördermaßnahme „Translationally oriented cooperation projects in the field of rare diseases “.