The fragile X mental retardation protein interacts with U-rich RNAs in a yeast three-hybrid system.
We recently identified several ESTs that bind to the fragile X mental retardation protein (FMRP) in vitro. To determine whether they interacted in vivo we performed three-hybrid screens in a Saccharomyces cerevisiae histidine auxotroph. We demonstrate that two of the ESTs support growth on histidine and transduce beta-galactosidase activity when co-expressed with FMRP under selective growth conditions. In contrast, the iron response element (IRE) RNA does not. Likewise, the ESTs do not support growth or transduce beta-galactosidase activity when co-expressed with the iron response element binding protein (IRP). Each EST is relatively small and has 40% identity with a sequence in FMR1 mRNA harboring FMRP binding determinants. Interestingly, while neither the ESTs contain a G-quartet structural motif they do contain U-rich sequences that are found in mRNA with demonstrated in vitro binding and in vivo association with FMRP. This indicates that U-rich elements comprise another motif recognized by FMRP.
Biochemical Molecular Neurobiology Laboratory, Department of Molecular Biology, New York State Institute for Basic Research in Developmental Disabilities, 1050 Forest Hill Road, Staten Island, NY 10314, USA.
Natalia
N
Dolzhanskaya
Ying Ju
YJ
Sung
James
J
Conti
Julia R
JR
Currie
Robert B
RB
Denman
D019677:Artificial Gene Fusion; D001483:Base Sequence; D001665:Binding Sites; D001921:Brain / Q000378:metabolism; D020224:Expressed Sequence Tags; D051860:Fragile X Messenger Ribonucleoprotein 1; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000737:chemistry* / Q000378:metabolism*; D016601:RNA-Binding Proteins; D012441:Saccharomyces cerevisiae / Q000235:genetics*; D012689:Sequence Homology, Nucleic Acid; D020798:Two-Hybrid System Techniques
D051860:Fragile X Messenger Ribonucleoprotein 1; D009419:Nerve Tissue Proteins; D012333:RNA, Messenger; D016601:RNA-Binding Proteins