Xenopus furry contributes to release of microRNA gene silencing.
A transcriptional corepressor, Xenopus furry (Xfurry), is expressed in the chordamesodermal region and induces secondary dorsal axes when overexpressed on the ventral side of the embryo. The N-terminal furry domain functions as a repressor, and the C-terminal leucine zipper (LZ) motifs /coiled-coil structure, found only in vertebrate homologs, contributes to the nuclear localization. The engrailed repressor (enR)+LZ repressor construct, which has properties similar to Xfurry, induced several chordamesodermal genes. In contrast, an antisense morpholino oligonucleotide, Xfurry-MO, and the activating construct, herpes simplex virus protein (VP16)+LZ, had effects opposite those of Xfurry overexpression. Because blocking protein synthesis with cycloheximide superinduced several Xfurry transcriptional targets, and because expression of enR+LZ induced such genes under cycloheximide treatment, we analyzed the role of an Xfurry transcriptional target, microRNA miR-15. Cycloheximide reduced the expression of primary miR-15 (pri-miR-15), whereas miR-15 reduced the expression of genes superinduced by cycloheximide treatment. These results show that Xfurry regulates chordamesodermal genes by contributing to repression of pretranscriptional gene silencing by miR-15.
Goto
Toshiyasu
T
Department of Life Sciences (Biology), Graduate School of Arts and Sciences, University of Tokyo, Meguro-ku, Tokyo 153-8902, Japan.
Fukui
Akimasa
A
Shibuya
Hiroshi
H
Keller
Ray
R
Asashima
Makoto
M
D021581:Active Transport, Cell Nucleus; D000818:Animals; D003513:Cycloheximide / Q000494:pharmacology; D005786:Gene Expression Regulation; D020868:Gene Silencing; D035683:MicroRNAs / Q000235:genetics*; D009672:Notochord; D012097:Repressor Proteins / Q000235:genetics*; D029867:Xenopus Proteins / Q000235:genetics* / Q000502:physiology; D014982:Xenopus laevis / Q000235:genetics*
C554339:FRY protein, Xenopus; D035683:MicroRNAs; D012097:Repressor Proteins; D029867:Xenopus Proteins; D003513:Cycloheximide