Proteins binding in vitro to normal and mutant FMR1 5'UTR mRNA

Expanded CGG repeats in the 5’UTR of fragile X messenger ribonucleoprotein 1 (FMR1) gene are translated to mutant protein containing polyglycine stretches (FMRpolyG), which evoke development of neurodegenerative disorder the fragile X-associated tremor/ataxia syndrome (FXTAS). However, little is known about the regulation of noncanonical translation of mutant FMR1 mRNA. Here, we show that insulin growth factor 2 binding proteins (IGF2BPs) directly bind to 5’UTR of FMR1 mRNA to selectively enhance biosynthesis of FMRpolyG.