Fragile X mental retardation protein interacts with TDG

Fragiie X syndrome is the most common form of inherited mental retardation disease, resulting from absent of expression of its disease gene FMR1. To study the function of the fragiie X mental retardation protein (FMRP) through protein/protein interaction, a mouse embryo cDNA library was screened by the yeast two-hybrid system. A clone was found to interact specifically with FMRP. The cDNA of this clone ( Genbank accession number af102875 ) encoded a protein highly homologous to human G/T mismatch-specific DNA thymine glycosylase ( hTDG ). Interactions between various alternatively spliced FMRP isoforms and a series of mTDG deletion proteins were further studied in the yeast two-hybrid system and their interaction amino acid regions were determined. interaction between FMRP and TDG existed inside exon 13 of FMRP ( amino acid residue 397-425 ) and around amino acid residue 122-346 of TDG. These results will be helpful to the study of the biological role of FMRP.