RNA CLIP-seq for Cugbp1, Mbnl1 and Ptbp1 in mouse C2C12 myoblasts. RNA CLIP-seq for Cugbp1, Mbnl1 and Ptbp1 in mouse C2C12 myoblasts

CUG-binding protein 1 (CUGBP1) and muscleblind-like 1 (MBNL1) are developmentally regulated RNA-binding proteins that are causally associated with myotonic dystrophy type 1. We extensively determined RNA-binding sites of CUGBP1 and MBNL1 to investigate their roles in RNA processing. We also analyzed polypyrimidine tract-binding protein (PTB) as a control. CUGBP1 and MBNL1 preferentially bind to alternatively spliced introns and exons, respectively, and regulate alternative splicing events. Moreover, CUGBP1 and MBNL1 are preferentially bound to the 3' untranslated regions (UTRs), in particular of genes for RNA-binding proteins, and facilitate decay of the bound mRNAs. In addition, CUGBP1 and MBNL1 mutually destabilize mRNA. Precise temporal regulation of CUGBP1 and MBNL1 are likely to be essential for accurate control of destabilization of a broad spectrum of genes as well as of alternative splicing events in cell differentiation and tissue development.