Regulation of miRNA abundance by RNA binding protein TOUGH in Arabidopsis

Guodong Ren, University of Nebraska-Lincoln
Meng Xie, University of Nebraska-Lincoln
Yongchao Dou, University of Nebraska-Lincoln
Shuxin Zhang, University of Nebraska-Lincoln
Chi Zhang, University of Nebraska-Lincoln
Bin Yu, University of Nebraska-Lincoln

Document Type Article

Copyright © 2012 NAS. Used by permission.

Abstract

MicroRNAs (miRNAs) are regulators of gene expression in plants and animals. The biogenesis of miRNAs is precisely controlled to secure normal development of organisms. Here we report that TOUGH (TGH) is a component of the DCL1–HYL1–SERRATE complex that processes primary transcripts of miRNAs [i.e., primary miRNAs (pri-miRNAs)] into miRNAs in Arabidopsis. Lack of TGH impairs multiple DCL activities in vitro and reduces the accumulation of miRNAs and siRNAs in vivo. TGH is an RNA-binding protein, binds pri-miRNAs and precursor miRNAs in vivo, and contributes to pri-miRNA–HYL1 interaction. These results indicate that TGH might regulate abundance of miRNAs through promoting DCL1 cleavage efficiency and/or recruitment of pri-miRNAs.