anticodon and Muscular-Dystrophies

The appearance of the premature translation termination codons (PTCs) in the transcript is the major cause of human genetic diseases. PTC-containing transcripts are rapidly degraded through nonsense-mediated decay (NMD) pathway. If such mRNA transcripts were translated in frame like normal transcripts, it would afford not only restoration of the level of full-length protein but also prevention of mRNA degradation by the NMD pathway. Here we describe a novel approach to read through PTC-containing mRNAs using suppressor tRNA that is introduced to cells by transfection. Luciferase reporter gene assay showed that nonsense and four-base codons were suppressed by the corresponding suppressor tRNAs derived from human tRNA(Ser). We also demonstrated that transfection of the suppressor tRNA to Ullrich disease fibroblasts, possessing a frameshift mutation in the collagen VI alpha2 gene, induced the upregulation of the collagen VI alpha2 mRNA and accumulation of the collagen VI protein. PTC suppression potentially provides a novel therapeutic means to rescue various PTC-related diseases.

Topics: Anticodon; Codon, Nonsense; Collagen Type VI; Frameshift Mutation; Genes, Reporter; Humans; Muscular Dystrophies; Peptide Chain Termination, Translational; RNA, Messenger; RNA, Transfer; RNA, Transfer, Ser; Suppression, Genetic