The chicken FMR1 gene is highly conserved with a CCT 5'-untranslated repeat and encodes an RNA-binding protein

• Published in: Genomics (San Diego, Calif.) Vol. 31; no. 1; pp. 3 - 12
• Main Authors: Price, D.K. (Carolinas Medical Center, Charlotte, NC.), Zhang, F.P, Ashley, C.T. Jr, Warren, S.T
• Format: Journal Article
• Language: English
• Published: San Diego, CA Elsevier 01.01.1996
• Subjects: ADN; AMINO ACID SEQUENCES; Animals; ARN; BINDING PROTEINS; Biological and medical sciences; BRAIN; CEREBRO; CHEMICAL COMPOSITION; CHICKENS; Chickens - genetics; CLONACION; CLONAGE; CLONING; COMPLEMENTARY DNA; COMPOSICION QUIMICA; COMPOSITION CHIMIQUE; Conserved Sequence; DNA; DNA - chemistry; DNA - genetics; ENCEPHALE; Fragile X Mental Retardation Protein; Fragile X Syndrome - genetics; Fundamental and applied biological sciences. Psychology; GENE; GENES; Genes. Genome; Humans; Intellectual Disability - genetics; Mice; Molecular and cellular biology; Molecular genetics; Molecular Sequence Data; Nerve Tissue Proteins - genetics; Nerve Tissue Proteins - metabolism; Nucleic Acid Conformation; NUCLEOTIDE SEQUENCE; POLLO; POULET; PROTEINAS AGLUTINANTES; PROTEINE DE LIAISON; REPETITIVE DNA; RNA; RNA-Binding Proteins - genetics; RNA-Binding Proteins - metabolism; SECUENCIA NUCLEICA; SEQUENCE NUCLEIQUE; STRUCTURAL GENES; Trinucleotide Repeats; tripartile repetitive element; Animal model; Nucleotide sequence; 3' terminal-Sequence; RNA binding protein; Homology; Molecular interaction; Secondary structure; Vertebrata; Complementary DNA; Gene; Microsatellite DNA; Chicken; Fragile X syndrome; Aves
• ISSN: 0888-7543; 1089-8646
• DOI: 10.1006/geno.1996.0002

The transcriptional silencing of the human gene, fragile X mental retardation 1 (FMR1), is due to abnormal methylation in response to an expanded 5'-untranslated CGG trinucleotide repeat and accounts for most cases of fragile X syndrome, a frequent inherited form of mental retardation. Although the encoded fragile X mental retardation protein (FMRP) is known to have properties of a RNA-binding protein, the precise function of FMRP remains to be elucidated. We report the cloning of the chicken homolog of FMR1 and show strong evolutionary conservation, with nucleotide and amino acid identities of 85 and 92%, respectively, between chicken and human. In place of the mammalian CGG trinucleotide repeat, a 99-nt tripartite repetitive element containing a CCT trinucleotide repeat flanked on both sides by dinucleotide repeats was identified. Blocks of highly conserved 3'-untranslated sequence were also found. Within the coding region, two copies each of the highly conserved K homology motif and the Arg-Gly-Gly (RGG) box motif, both ribonucleotide particle family domains implicated in RNA binding, were identified. Chicken FMRP was found to bind RNA in vitro, and this activity correlated with the presence of the carboxy-terminal portion of the protein that includes the RGG motifs.