The RNA-binding protein Mex3b has a fine-tuning system for mRNA regulation in early Xenopus development.
Post-transcriptional control by RNA-binding proteins is a precise way to assure appropriate levels of gene expression. Here, we identify a novel mRNA regulatory system involving Mex3b (RKHD3) and demonstrate its role in FGF signaling. mex3b mRNA has a 3' long conserved UTR, named 3'LCU, which contains multiple elements for both mRNA destabilization and translational enhancement. Notably, Mex3b promotes destabilization of its own mRNA by binding to the 3'LCU, thereby forming a negative autoregulatory loop. The combination of positive regulation and negative autoregulation constitutes a fine-tuning system for post-transcriptional control. In early embryogenesis, Mex3b is involved in anteroposterior patterning of the neural plate. Consistent with this, Mex3b can attenuate FGF signaling and destabilize mRNAs for the FGF signaling components Syndecan 2 and Ets1b through their 3' UTRs. These data suggest that the 3'LCU-mediated fine-tuning system determines the appropriate level of mex3b expression, which in turn contributes to neural patterning through regulating FGF signaling.
Takada
Hitomi
H
Department of Biological Sciences, Graduate School of Science, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
Kawana
Takahiro
T
Ito
Yuzuru
Y
Kikuno
Reiko F
RF
Mamada
Hiroshi
H
Araki
Toshiyuki
T
Koga
Hisashi
H
Asashima
Makoto
M
Taira
Masanori
M
D020413:3' Untranslated Regions; D000595:Amino Acid Sequence; D000818:Animals; D030801:Animals, Genetically Modified; D001483:Base Sequence; D019521:Body Patterning; D017931:DNA Primers / Q000235:genetics; D005346:Fibroblast Growth Factors / Q000235:genetics / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D008954:Models, Biological; D008969:Molecular Sequence Data; D054258:Neural Plate / Q000196:embryology / Q000378:metabolism; D050784:Proto-Oncogene Protein c-ets-1 / Q000235:genetics / Q000378:metabolism; D012323:RNA Processing, Post-Transcriptional; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid; D015398:Signal Transduction; D053669:Syndecan-2 / Q000235:genetics / Q000378:metabolism; D014981:Xenopus / Q000196:embryology* / Q000235:genetics / Q000378:metabolism*; D029867:Xenopus Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*
D020413:3' Untranslated Regions; D017931:DNA Primers; C543673:Mex3b protein, Xenopus; D050784:Proto-Oncogene Protein c-ets-1; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; D029867:Xenopus Proteins; C508248:sdc2 protein, Xenopus; D053669:Syndecan-2; D005346:Fibroblast Growth Factors