title: RNA Foci, CUGBP1, and ZNF9 are the primary targets of the mutant CUG and CCUG repeats expanded in myotonic dystrophies type 1 and type 2.
abstract: Expansions of noncoding CUG and CCUG repeats in myotonic dystrophies type 1 (DM1) and DM2 cause complex molecular pathology, the features of which include accumulation of RNA aggregates and misregulation of the RNA-binding proteins muscleblind-like 1 (MBNL1) and CUG-binding protein 1 (CUGBP1). CCUG repeats also decrease amounts of the nucleic acid binding protein ZNF9. Using tetracycline (Tet)-regulated monoclonal cell models that express CUG and CCUG repeats, we found that low levels of long CUG and CCUG repeats result in nuclear and cytoplasmic RNA aggregation with a simultaneous increase of CUGBP1 and a reduction of ZNF9. Elevation of CUGBP1 and reduction of ZNF9 were also observed before strong aggregation of the mutant CUG/CCUG repeats. Degradation of CUG and CCUG repeats normalizes ZNF9 and CUGBP1 levels. Comparison of short and long CUG and CCUG RNAs showed that great expression of short repeats form foci and alter CUGBP1 and ZNF9; however, long CUG/CCUG repeats misregulate CUGBP1 and ZNF9 much faster than high levels of the short repeats. These data suggest that correction of DM1 and DM2 might be achieved by complete and efficient degradation of CUG and CCUG repeats or by a simultaneous disruption of CUG/CCUG foci and correction of CUGBP1 and ZNF9.
authors: Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, Texas, USA.
authors: Karlie
authors: K
authors: Jones
authors: Bingwen
authors: B
authors: Jin
authors: Polina
authors: P
authors: Iakova
authors: Claudia
authors: C
authors: Huichalaf
authors: Partha
authors: P
authors: Sarkar
authors: Christiane
authors: C
authors: Schneider-Gold
authors: Benedikt
authors: B
authors: Schoser
authors: Giovanni
authors: G
authors: Meola
authors: Ann-Bin
authors: AB
authors: Shyu
authors: Nikolai
authors: N
authors: Timchenko
authors: Lubov
authors: L
authors: Timchenko
mesh_terms: D000067879:CELF1 Protein; D002460:Cell Line; D004318:Doxycycline / Q000494:pharmacology; D006801:Humans; D009154:Mutation / Q000235:genetics*; D020967:Myotonic Disorders / Q000235:genetics*; D009223:Myotonic Dystrophy / Q000235:genetics*; D012313:RNA / Q000378:metabolism*; D016601:RNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic / Q000187:drug effects
chemical_list: D000067879:CELF1 Protein; C102843:CELF1 protein, human; C433227:CNBP protein, human; D016601:RNA-Binding Proteins; D012313:RNA; D004318:Doxycycline