Ataluren (PTC124) is a novel, orally administered drug that targets nonsense mutations. Ataluren is approved for use by the European Medicines Agency to treat Duchenne Muscular Dystrophy in patients aged 5 years and older who are able to walk.

0.01-3 μM PTC124 promoted dose-dependent through-reading of all three nonsense codons in HEK293 cells containing the LUC-190 nonsense allele, with the highest readings at UGA, followed by UAG, and then UAA, but it did not inhibit multiple proximal nonsense codons. 17 μM PTC124 was consistent with the experimental assay reported for the stable cell line, and the results of PTC124 (17 PTC124 (17 μM) promotes significant production of myotrophic proteins in primary myoblasts from patients with Duchenne-type muscular dystrophy (DMD) or MDXMDX mice expressing the nonsense allele of myotrophic dystrophic protease.PTC124 selectively promotes the readthrough of ribosomal premature termination codons, but not normal termination codons, even at concentrations substantially higher than those required to achieve maximal activity. PTC124 is a more potent nonsense inhibitor than gentamicin, which is active only at higher concentrations, and shows a 4- to 15-fold stimulation of read-through relative to the control.PTC124, similar to gentamicin, is most active at pyrimidines (especially cytosine, C) following nonsense codons.

0.01-3 μM PTC124 promoted dose-dependent through-reading of all three nonsense codons in HEK293 cells containing the LUC-190 nonsense allele, with the highest readings at UGA, followed by UAG, and then UAA, but it did not inhibit multiple proximal nonsense codons. 17 μM PTC124 was consistent with the experimental assay reported for the stable cell line, and the results of PTC124 (17 PTC124 (17 μM) promotes significant production of myotrophic proteins in primary myoblasts from patients with Duchenne-type muscular dystrophy (DMD) or MDXMDX mice expressing the nonsense allele of myotrophic dystrophic protease.PTC124 selectively promotes the readthrough of ribosomal premature termination codons, but not normal termination codons, even at concentrations substantially higher than those required to achieve maximal activity. PTC124 is a more potent nonsense inhibitor than gentamicin, which is active only at higher concentrations, and shows a 4- to 15-fold stimulation of read-through relative to the control.PTC124, similar to gentamicin, is most active at pyrimidines (especially cytosine, C) following nonsense codons.

PTC124 (Ataluren) is prepared in DMSO and stored, and then diluted with appropriate medium (DMSO 1%) before use[2]. Duplicate samples of HEK293 cells harbouring LUC-190 (UGA) are incubated in the presence of 5?μM PTC124 (treated) or 1% DMSO (untreated) for 20?h. The cells are collected, washed twice in phosphate buffered saline (PBS), resuspended in sample buffer (Bio-Rad) and shipped on dry ice to Kendrick Laboratories for two-dimensional electrophoretic analysis Isoelectric focusing (pH?3.5-10) is carried out in glass tubes for 20,000 V-hours. One?μg of a tropomyosin internal standard is added to each sample. Second dimension SDS slab gel electrophoresis is carried out for approximately 6?h at 25?mA per gel. After electrophoresis, gels are transferred to PVDF paper. Computerized analysis of spot mobility used Phoretix software[2].