title: Target protectors reveal dampening and balancing of Nodal agonist and antagonist by miR-430.
abstract: MicroRNAs (miRNAs) repress hundreds of target messenger RNAs (mRNAs), but the physiological roles of specific miRNA-mRNA interactions remain largely elusive. We report that zebrafish microRNA-430 (miR-430) dampens and balances the expression of the transforming growth factor-beta (TGF-beta) Nodal agonist squint and the TGF-beta Nodal antagonist lefty. To disrupt the interaction of specific miRNA-mRNA pairs, we developed target protector morpholinos complementary to miRNA binding sites in target mRNAs. Protection of squint or lefty mRNAs from miR-430 resulted in enhanced or reduced Nodal signaling, respectively. Simultaneous protection of squint and lefty or absence of miR-430 caused an imbalance and reduction in Nodal signaling. These findings establish an approach to analyze the in vivo roles of specific miRNA-mRNA pairs and reveal a requirement for miRNAs in dampening and balancing agonist/antagonist pairs.
authors.affiliation: Department of Molecular and Cellular Biology, Harvard University, 16 Divinity Avenue, Cambridge, MA 02138, USA.
authors.forename: Wen-Yee
authors.initials: WY
authors.lastname: Choi
authors.forename: Antonio J
authors.initials: AJ
authors.lastname: Giraldez
authors.forename: Alexander F
authors.initials: AF
authors.lastname: Schier
mesh_terms: D020413:3' Untranslated Regions; D000818:Animals; D004625:Embryo, Nonmammalian / Q000502:physiology; D047108:Embryonic Development; D005786:Gene Expression Regulation; D055458:Left-Right Determination Factors; D035683:MicroRNAs / Q000378:metabolism*; D009154:Mutation; D055457:Nodal Protein; D055456:Nodal Signaling Ligands; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism*; D016212:Transforming Growth Factor beta / Q000819:agonists / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000378:metabolism*; D015027:Zebrafish / Q000196:embryology / Q000235:genetics* / Q000378:metabolism; D029961:Zebrafish Proteins / Q000235:genetics*
chemical_list: D020413:3' Untranslated Regions; D055458:Left-Right Determination Factors; D035683:MicroRNAs; D055457:Nodal Protein; D055456:Nodal Signaling Ligands; D012333:RNA, Messenger; D016212:Transforming Growth Factor beta; D029961:Zebrafish Proteins; C117508:lft1 protein, zebrafish; C485171:ndr1 protein, zebrafish