Genomics Inform.  2009 Dec;7(4):181-186.

RNA Mapping of Mutant Myotonic Dystrophy Protein Kinase 3'-Untranslated Region Transcripts

• Song MS
• Lee SW

Abstract

Myotonic dystrophy type 1 (DM1), which is a dominantly inherited neurodegenerative disorder, results from a CTG trinucleotide repeat expansion in the 3'-untranslated region (3'-UTR) of the myotonic dystrophy protein kinase (DMPK) gene. Retention of mutant DMPK (mDMPK) transcripts in the nuclei of affected cells has been known to be the main cause of pathogenesis of the disease. Thus, reducing the RNA toxicity through elimination of the mutant RNA has been suggested as one therapeutic strategy against DM1. In this study, we suggested RNA replacement with a trans -splicing ribozyme as an alternate genetic therapeutic approach for amelioration of DM1. To this end, we identified the regions of mDMPK 3'-UTR RNA that were accessible to ribozymes by using an RNA mapping strategy based on a trans - splicing ribozyme library. We found that particularly accessible sites were present not only upstream but also downstream of the expanded repeat sequence. Repair or replacement of the mDMPK transcript with the specific ribozyme will be useful for DM1 treatment through reduction of toxic mutant transcripts and simultaneously restore wild-type DMPK or release nucleus-entrapped mDMPK transcripts to the cytoplasm.

Keyword

group I intron; myotonic dystrophy protein kinase; RNA mapping; RNA replacement; trans-splicing ribozyme; trinucleotide repeat expansion

MeSH Terms

Cytoplasm
Myotonic Dystrophy
Neurodegenerative Diseases
Protein Kinases
Protein-Serine-Threonine Kinases
Retention (Psychology)
RNA
RNA, Catalytic
Trinucleotide Repeat Expansion
Protein Kinases
Protein-Serine-Threonine Kinases
RNA
RNA, Catalytic