The FMR-1 protein is cytoplasmic, most abundant in neurons and appears normal in carriers of a fragile X premutation.
Fragile X mental retardation syndrome is caused by the unstable expansion of a CGG repeat in the FMR-1 gene. In patients with a full mutation, abnormal methylation results in suppression of FMR-1 transcription. FMR-1 is expressed in many tissues but its function is unknown. We have raised monoclonal antibodies specific for the FMR-1 protein. They detect 4-5 protein bands which appear identical in cells of normal males and of males carrying a premutation, but are absent in affected males with a full mutation. Immunohistochemistry shows a cytoplasmic localization of FMR-1. The highest levels were observed in neurons, while glial cells contain very low levels. In epithelial tissues, levels of FMR-1 were higher in dividing layers. In adult testis, FMR-1 was detected only in spermatogonia. FMR-1 was not detected in dermis and cardiac muscle except under pathological conditions.
Devys
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Laboratoire de Génétique Moléculaire des Eucaryotes du CNRS, Unité 184 de l'INSERM, Faculté de Médecine, Strasbourg, France.
Lutz
Y
Y
Rouyer
N
N
Bellocq
J P
JP
Mandel
J L
JL
D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal; D001483:Base Sequence; D002460:Cell Line; D003001:Cloning, Molecular; D004247:DNA / Q000235:genetics / Q000378:metabolism; D005091:Exons; D051860:Fragile X Messenger Ribonucleoprotein 1; D005600:Fragile X Syndrome / Q000235:genetics* / Q000378:metabolism; D006580:Genetic Carrier Screening; D006801:Humans; D008297:Male; D008745:Methylation; D008969:Molecular Sequence Data; D009154:Mutation; D009419:Nerve Tissue Proteins / Q000096:biosynthesis / Q000235:genetics* / Q000378:metabolism*; D009474:Neurons / Q000378:metabolism*; D009838:Oligodeoxyribonucleotides; D009928:Organ Specificity; D016601:RNA-Binding Proteins; D011993:Recombinant Fusion Proteins / Q000032:analysis / Q000096:biosynthesis; D012091:Repetitive Sequences, Nucleic Acid; D014162:Transfection
D000911:Antibodies, Monoclonal; D004247:DNA; D051860:Fragile X Messenger Ribonucleoprotein 1; D009419:Nerve Tissue Proteins; D009838:Oligodeoxyribonucleotides; D016601:RNA-Binding Proteins; D011993:Recombinant Fusion Proteins; C497683:FMR1 protein, human