The protein product of the fragile X gene, FMR1, has characteristics of an RNA-binding protein

Haruhiko Siomi, Mikiko C. Siomi, Robert L. Nussbaum, Gideon Dreyfuss

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Fragile X syndrome is one of the most common human genetic diseases and the most common cause of hereditary mental retardation. The gene that causes fragile X syndrome, FMR1, was recently identified and sequenced and found to encode a putative protein of unknown function. Here we report that FMR1 contains two types of sequence motifs recently found in RNA-binding proteins: an RGG box and two heterogeneous nuclear RNP K homology domains. We also demonstrate that FMR1 binds RNA in vitro. Using antibodies to FMR1, we detect its expression in divergent organisms and in cells of unaffected humans, but fragile X-affected patients express little or no FMR1. These findings demonstrate that FMR1 expression is directly correlated with the fragile X syndrome and suggest that anti-FMR1 antibodies will be important for diagnosis of fragile X syndrome. Furthermore, the RNA binding activity of FMR1 opens the way to understanding the function of FMR1.

Original languageEnglish
Pages (from-to)291-298
Number of pages8
Issue number2
Publication statusPublished - 1993 Jul 30
Externally publishedYes


ASJC Scopus subject areas

  • Biochemistry, Genetics and Molecular Biology(all)

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