title: Drosophila genome-wide RNAi screen identifies multiple regulators of HIF-dependent transcription in hypoxia.
abstract: Hypoxia-inducible factors (HIFs) are a family of evolutionary conserved alpha-beta heterodimeric transcription factors that induce a wide range of genes in response to low oxygen tension. Molecular mechanisms that mediate oxygen-dependent HIF regulation operate at the level of the alpha subunit, controlling protein stability, subcellular localization, and transcriptional coactivator recruitment. We have conducted an unbiased genome-wide RNA interference (RNAi) screen in Drosophila cells aimed to the identification of genes required for HIF activity. After 3 rounds of selection, 30 genes emerged as critical HIF regulators in hypoxia, most of which had not been previously associated with HIF biology. The list of genes includes components of chromatin remodeling complexes, transcription elongation factors, and translational regulators. One remarkable hit was the argonaute 1 (ago1) gene, a central element of the microRNA (miRNA) translational silencing machinery. Further studies confirmed the physiological role of the miRNA machinery in HIF-dependent transcription. This study reveals the occurrence of novel mechanisms of HIF regulation, which might contribute to developing novel strategies for therapeutic intervention of HIF-related pathologies, including heart attack, cancer, and stroke.
authors.affiliation: Instituto Leloir, Universidad de Buenos Aires, Buenos Aires, Argentina.
authors.forename: Andrés
authors.initials: A
authors.lastname: Dekanty
authors.forename: Nuria M
authors.initials: NM
authors.lastname: Romero
authors.forename: Agustina P
authors.initials: AP
authors.lastname: Bertolin
authors.forename: María G
authors.initials: MG
authors.lastname: Thomas
authors.forename: Claudia C
authors.initials: CC
authors.lastname: Leishman
authors.forename: Joel I
authors.initials: JI
authors.lastname: Perez-Perri
authors.forename: Graciela L
authors.initials: GL
authors.lastname: Boccaccio
authors.forename: Pablo
authors.initials: P
authors.lastname: Wappner
mesh_terms: D000818:Animals; D060565:Argonaute Proteins; D051792:Basic Helix-Loop-Helix Proteins / Q000378:metabolism*; D002460:Cell Line; D029721:Drosophila Proteins / Q000235:genetics; D004331:Drosophila melanogaster / Q000235:genetics* / Q000378:metabolism; D039642:Eukaryotic Initiation Factors / Q000235:genetics; D055106:Genome-Wide Association Study; D000860:Hypoxia / Q000235:genetics* / Q000378:metabolism; D034622:RNA Interference; D014158:Transcription, Genetic
chemical_list: D060565:Argonaute Proteins; D051792:Basic Helix-Loop-Helix Proteins; D029721:Drosophila Proteins; D039642:Eukaryotic Initiation Factors; C489654:AGO1 protein, Drosophila