title: Transcription activator-like effector proteins induce the expression of the frataxin gene.
abstract: Genes encoding transcription activator-like effector (TALE) proteins may be engineered to target specific DNA sequences. TALEs 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 reduced expression of frataxin because of elongation of a trinucleotide (GAA) repeat in intron 1. Our aim was to develop a potential treatment for FRDA by increasing the expression of the frataxin gene. We engineered 12 TALE genes (TALE(Frat)) encoding TALE(Frat) proteins, each specifically targeting different 14-bp DNA sequences within the proximal region of the human frataxin promoter. When the genes encoding these TALE(Frat) proteins were fused with a transcription activator, that is, four VP16 peptides (i.e., VP64), the resulting TALE(Frat)-VP64 proteins induced the expression of an mCherry reporter gene fused to a mini-cytomegalovirus promoter able to be activated by the insertion of the frataxin proximal promoter upstream to the minipromoter. These TALE(Frat)-VP64 proteins also increased, by 2- to 3-fold, frataxin gene expression (detected by qRT-PCR) in the cells. We conclude that TALE(Frat) proteins targeting the frataxin promoter may be used to increase the expression of frataxin mRNA and potentially could alleviate the symptoms of Friedreich ataxia. TALE methodology opens a new field of research, which could be used to develop TALE proteins to treat other diseases by inducing the expression of specific genes.
authors.affiliation: Department of Molecular Medicine, Laval University, and Centre de Recherche du Centre Hospitalier Universitaire de, 2705 boul. Laurier Québec, PQ G1V4G2, Canada. jacques-p.tremblay@crchul.ulaval.ca
authors.forename: Jacques P
authors.initials: JP
authors.lastname: Tremblay
authors.forename: Pierre
authors.initials: P
authors.lastname: Chapdelaine
authors.forename: Zoé
authors.initials: Z
authors.lastname: Coulombe
authors.forename: Joel
authors.initials: J
authors.lastname: Rousseau
mesh_terms: D001483:Base Sequence; D002460:Cell Line; D005621:Friedreich Ataxia / Q000235:genetics / Q000628:therapy; D015870:Gene Expression; D017930:Genes, Reporter; D017405:Herpes Simplex Virus Protein Vmw65 / Q000235:genetics; D006801:Humans; D007438:Introns; D033862:Iron-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D008164:Luminescent Proteins / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D010957:Plasmids; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism; D019680:Trinucleotide Repeat Expansion; D000096923:Frataxin; D000097573:Red Fluorescent Protein
chemical_list: D017405:Herpes Simplex Virus Protein Vmw65; D033862:Iron-Binding Proteins; D008164:Luminescent Proteins; D012333:RNA, Messenger; D014157:Transcription Factors; D000096923:Frataxin; D000097573:Red Fluorescent Protein