Genetic analysis of the role of the asparaginyl hydroxylase factor inhibiting hypoxia-inducible factor (HIF) in regulating HIF transcriptional target genes

摘要: Hypoxia-inducible factor (HIF) is a heterodimeric transcription that directs broad range of cellular responses to hypoxia. Recent studies have defined set 2-oxoglutarate and Fe(II)-dependent dioxygenases modify HIF-alpha subunits by prolyl asparaginyl hydroxylation. These processes potentially provide dual system control, down-regulating both stability transcriptional activity. Although genetic analyses in primitive organisms mammalian cells demonstrated critical role for the hydroxylase pathway regulation HIF, analogous not been performed on HIF pathway, its directing expression endogenous targets has yet clearly defined. Here we demonstrate, using small interfering RNA-mediated FIH suppression controlled overexpression doxycycline-inducible system, alterations directions reciprocal effects target genes. were observed normoxic severely hypoxic but anoxic cells. Evidence activity contrasted with results PHD2, suggesting these enzymes display different oxygen dependence vivo, PHD2 requiring higher levels biological Our demonstrate an important physiological regulating HIF-dependent genes over wide tensions indicate inhibition potential augment gene even severe