title: ROD1 is a seedless target gene of hypoxia-induced miR-210.
abstract: Most metazoan microRNA (miRNA) target sites have perfect pairing to the "seed" sequence, a highly conserved region centering on miRNA nucleotides 2-7. Thus, complementarity to this region is a necessary requirement for target prediction algorithms. However, also non-canonical miRNA binding can confer target regulation. Here, we identified a seedless target of miR-210, a master miRNA of the hypoxic response. We analyzed 20 genes that were inversely correlated to miR-210 expression and did not display any complementarity with miR-210 seed sequence. We validated ROD1 (Regulator of Differentiation 1, also named PTBP3, Polypyrimidine Tract Binding protein 3) as a miR-210 seedless transcript enriched in miR-210-containing RNA-induced silencing complexes. ROD1 was not indirectly targeted by a miR-210-induced miRNA. Conversely, we identified a "centered" miR-210 binding site in ROD1 involving 10 consecutive bases in the central portion of miR-210. Reporter assays showed that miR-210 inhibited ROD1 by the direct binding to this sequence, demonstrating that ROD1 is a bona fide seedless target of miR-210. As expected, both ROD1 mRNA and protein were down-modulated upon hypoxia in a miR-210 dependent manner. ROD1 targeting by miR-210 was biologically significant: the rescue of ROD1 inhibition significantly increased hypoxia-induced cell death. These data highlight the importance of ROD1 regulation by miR-210 for cell homeostasis.
authors.affiliation: Istituto Dermopatico dell'Immacolata IRCCS, Roma, Italy.
authors.forename: Pasquale
authors.initials: P
authors.lastname: Fasanaro
authors.forename: Sveva
authors.initials: S
authors.lastname: Romani
authors.forename: Christine
authors.initials: C
authors.lastname: Voellenkle
authors.forename: Biagina
authors.initials: B
authors.lastname: Maimone
authors.forename: Maurizio C
authors.initials: MC
authors.lastname: Capogrossi
authors.forename: Fabio
authors.initials: F
authors.lastname: Martelli
mesh_terms: D017209:Apoptosis; D020029:Base Pairing; D001483:Base Sequence; D001665:Binding Sites; D002470:Cell Survival / Q000235:genetics; D005786:Gene Expression Regulation; D057809:HEK293 Cells; D006801:Humans; D000860:Hypoxia; D035683:MicroRNAs / Q000737:chemistry / Q000235:genetics*; D038941:Polypyrimidine Tract-Binding Protein / Q000737:chemistry / Q000235:genetics*; D034622:RNA Interference; D015203:Reproducibility of Results; D014158:Transcription, Genetic
chemical_list: C543800:MIRN210 microRNA, human; D035683:MicroRNAs; C118823:PTBP3 protein, human; D038941:Polypyrimidine Tract-Binding Protein