Identification of FMRP-associated mRNAs using yeast three-hybrid system.
Fragile X syndrome, one of the most common forms of inherited mental retardation, results from the absence of the fragile X mental retardation protein (FMRP), which is encoded by the fragile X mental retardation gene 1 (FMR1). FMRP is an RNA-binding protein involved in translational regulation of targeted mRNAs. Identification of targeted mRNAs associated with FMRP is important to understand the function of FMRP and the pathogenic basis of the fragile X syndrome. Employing a yeast three-hybrid system and a human fetal hippocampus cDNA library, we identified 22 candidate target mRNAs, and 18 of them were confirmed to be associated with FMRP in vitro by gel retardation. Some of these mRNAs code for structural proteins, enzymes or proteins involved in cellular processes, especially in the development and function of neural system. To further investigate the role of FMRP in regulating targeted gene expression, we analyzed the expression profile of TXNRD1, one of the candidate mRNAs, after knocking down the expression of endogenous FMRP by siRNA. The results showed that endogenous TXNRD1 translation increased along with depletion of FMRP, which suggested FMRP negatively regulates TXNRD1 translation.
Zou
Ke
K
National Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, Tsinghua University, Beijing, People's Republic of China.
Liu
Jian
J
Zhu
Ning
N
Lin
Jianhong
J
Liang
Qi
Q
Brown
W Ted
WT
Shen
Yan
Y
Zhong
Nanbert
N
D000818:Animals; D002478:Cells, Cultured; D051860:Fragile X Messenger Ribonucleoprotein 1 / Q000235:genetics / Q000378:metabolism*; D005786:Gene Expression Regulation; D015723:Gene Library; D006367:HeLa Cells; D006624:Hippocampus / Q000737:chemistry / Q000378:metabolism; D006801:Humans; D008297:Male; D051379:Mice; D018345:Mice, Knockout; D014176:Protein Biosynthesis / Q000235:genetics; D012333:RNA, Messenger / Q000302:isolation & purification* / Q000378:metabolism; D054481:Thioredoxin Reductase 1 / Q000235:genetics / Q000378:metabolism; D020798:Two-Hybrid System Techniques
D051860:Fragile X Messenger Ribonucleoprotein 1; D012333:RNA, Messenger; D054481:Thioredoxin Reductase 1; C497683:FMR1 protein, human; C516124:TXNRD1 protein, human