Abstract kindly supplied by Hediye Isik
Authors : Tremblay Jacques P, Chapdelaine Pierre, Coulombe Zoé, Rousseau Joël,
Publication Date : 2012/5/16
Pubmed ID :22587705
Genes coding for Tal effector (TALE) proteins may be engineered to target specific DNA sequences. TALEs are fused with a transcription activator can be used to specifically induce the expression of a gene. This could lead to completely new therapies for several diseases. We have applied this potential therapeutic approach to Friedreich ataxia (FRDA) as an example. FRDA is due to a reduced expression of frataxin following an elongation of a trinucleotide (GAA) repeat in intron 1. Aim: To develop a potential treatment for FRDA by increasing the expression of the frataxin gene.
Results: We have engineered 12 TALE genes (TALEFrat) coding for TALEFrat proteins each specifically targeting different 14 bp DNA sequences within the proximal region of the human frataxin promoter. When the genes of these TALEFrat were fused with a transcription activator, i.e., four VP16 peptides (i.e., VP64), the resulting TALEFrat-VP64 proteins induced the expression of a mCherry reporter gene fused to a mini-CMV promoter able to be activated by the insertion of the frataxin proximal promoter upstream to the mini promoter. These TALEFrat-VP64 also increased by 2 to 3 folds the frataxin gene expression (detected by qRT-PCR) in the cells. Conclusion: TALEFrat proteins targeting the frataxin promoter are thus a method to increase the expression of frataxin mRNA and potentially could alleviate the symptoms of Friedreich ataxia. This new methodology of TALE effector opens a new field, which could be used to develop TALE proteins to treat other diseases by inducing the expression of specific genes.