Recombinant full-length human MBNL3 protein was used as the immunogen for the MBNL3 antibody.
Pre-mRNA splicing is a critical step in the posttranscriptional regulation of gene expression. Several protein complexes are involved in proper mRNA splicing and transport. The muscleblind proteins, MBNL1, MBNL2 and MBNL3, promote inclusion or exclusion of specific exons on different pre-mRNAs by antagonizing the activity of CUG-BP and ETR-3-like factors bound to distinct intronic sites. MBNL1 and 2, which associate with expanded CUG repeats in vitro, localize to the nuclear foci in both DM1 and DM2 (myotonic dystrophy types 1 and 2), suggesting that the nuclear accumulation of mutant RNA is pathogenic in DM1, therefore implicating MBNL1 and 2 in the pathogenesis of both disorders. MBNL3, a 354 amino acid protein, inhibits expression of muscle differentiation, opposite to the function of MBNL1, which functions as a promoter of muscle differentiation. MBNL3 shows strong expression in placenta.
