title: miR-191 regulates mouse erythroblast enucleation by down-regulating Riok3 and Mxi1.
abstract: Using RNA-seq technology, we found that the majority of microRNAs (miRNAs) present in CFU-E erythroid progenitors are down-regulated during terminal erythroid differentiation. Of the developmentally down-regulated miRNAs, ectopic overexpression of miR-191 blocks erythroid enucleation but has minor effects on proliferation and differentiation. We identified two erythroid-enriched and developmentally up-regulated genes, Riok3 and Mxi1, as direct targets of miR-191. Knockdown of either Riok3 or Mxi1 blocks enucleation, and either physiological overexpression of miR-191 or knockdown of Riok3 or Mxi1 blocks chromatin condensation. Thus, down-regulation of miR-191 is essential for erythroid chromatin condensation and enucleation by allowing up-regulation of Riok3 and Mxi1.
authors.affiliation: Whitehead Institute for Biomedical Research, Cambridge, Massachusetts 02142, USA.
authors.forename: Lingbo
authors.initials: L
authors.lastname: Zhang
authors.forename: Johan
authors.initials: J
authors.lastname: Flygare
authors.forename: Piu
authors.initials: P
authors.lastname: Wong
authors.forename: Bing
authors.initials: B
authors.lastname: Lim
authors.forename: Harvey F
authors.initials: HF
authors.lastname: Lodish
mesh_terms: D000818:Animals; D051792:Basic Helix-Loop-Helix Proteins / Q000235:genetics / Q000378:metabolism*; D002454:Cell Differentiation; D002460:Cell Line; D002467:Cell Nucleus / Q000378:metabolism; D002478:Cells, Cultured; D015536:Down-Regulation; D004900:Erythroblasts / Q000166:cytology* / Q000378:metabolism; D055785:Gene Knockdown Techniques; D051379:Mice; D035683:MicroRNAs / Q000378:metabolism*; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D025521:Tumor Suppressor Proteins / Q000235:genetics / Q000378:metabolism*; D015854:Up-Regulation
chemical_list: D051792:Basic Helix-Loop-Helix Proteins; D035683:MicroRNAs; D017346:Protein Serine-Threonine Kinases; D025521:Tumor Suppressor Proteins; C555937:MIRN191 microRNA, mouse; C512788:Mxi1 protein, mouse