title: Arabidopsis Argonaute10 specifically sequesters miR166/165 to regulate shoot apical meristem development.
abstract: The shoot apical meristem (SAM) comprises a group of undifferentiated cells that divide to maintain the plant meristem and also give rise to all shoot organs. SAM fate is specified by class III HOMEODOMAIN-LEUCINE ZIPPER (HD-ZIP III) transcription factors, which are targets of miR166/165. In Arabidopsis, AGO10 is a critical regulator of SAM maintenance, and here we demonstrate that AGO10 specifically interacts with miR166/165. The association is determined by a distinct structure of the miR166/165 duplex. Deficient loading of miR166 into AGO10 results in a defective SAM. Notably, the miRNA-binding ability of AGO10, but not its catalytic activity, is required for SAM development, and AGO10 has a higher binding affinity for miR166 than does AGO1, a principal contributor to miRNA-mediated silencing. We propose that AGO10 functions as a decoy for miR166/165 to maintain the SAM, preventing their incorporation into AGO1 complexes and the subsequent repression of HD-ZIP III gene expression.
authors.affiliation: Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX 77843, USA.
authors.forename: Hongliang
authors.initials: H
authors.lastname: Zhu
authors.forename: Fuqu
authors.initials: F
authors.lastname: Hu
authors.forename: Ronghui
authors.initials: R
authors.lastname: Wang
authors.forename: Xin
authors.initials: X
authors.lastname: Zhou
authors.forename: Sing-Hoi
authors.initials: SH
authors.lastname: Sze
authors.forename: Lisa Wen
authors.initials: LW
authors.lastname: Liou
authors.forename: Ashley
authors.initials: A
authors.lastname: Barefoot
authors.forename: Martin
authors.initials: M
authors.lastname: Dickman
authors.forename: Xiuren
authors.initials: X
authors.lastname: Zhang
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000378:metabolism*; D060565:Argonaute Proteins; D018506:Gene Expression Regulation, Plant; D018519:Meristem / Q000254:growth & development*; D035683:MicroRNAs / Q000235:genetics*; D018520:Plant Shoots; D018749:RNA, Plant / Q000235:genetics*
chemical_list: D029681:Arabidopsis Proteins; D060565:Argonaute Proteins; D035683:MicroRNAs; D018749:RNA, Plant; C529694:AT5G43810 protein, Arabidopsis