title: The role of nitric oxide (NO) in stability regulation of hypoxia inducible factor-1alpha (HIF-1alpha).
abstract: Hypoxia inducible factor-1 (HIF-1) is a master regulator under conditions of decreased oxygen availability. As a hypoxia inducible transcription factor HIF-1 is a heterodimer composed of the helix-loop-helix-Per-Arnt-Sim (bHLH-PAS) proteins HIF-1alpha and the aryl hydrocarbon nuclear translocator (ARNT) also known as HIF-1beta. The HIF-1 transcriptional system senses decreased oxygen availability and transmits this signal into patho-physiological responses such as angiogenesis, erythropoiesis, vasomotor control, an altered energy metabolism, as well as cell survival decisions. Among recent advances are the discoveries that reactive nitrogen species (RNS), oxygen species (ROS), cytokines, and growth factors participate in stability regulation of HIF-1alpha and HIF-1 transactivation during normoxia. Here we summarize current knowledge and existing concepts that help to understand how NO affects protein accumulation of HIF-1alpha. Considering the fundamental role of radicals, especially NO, as signaling molecules makes HIF-1alpha an attractive target under conditions of NO formation that may be attributed to both, physiology and pathology. Although initial observations showed that NO inhibits hypoxia-induced HIF-1alpha stabilization and HIF-1 transcriptional activation, later studies indicated that exposure of various cells to chemically diverse NO donors or conditions of endogenous NO formation under normoxic conditions induced HIF-1alpha accumulation, HIF-1-DNA binding, and activation of downstream target gene expression. These contrasting situations evoked by NO provide insights into basic chemical reactions, biochemical signal transduction pathways with broad implications for medicine.
authors.affiliation: Department of Cell Biology, Faculty of Biology, University of Kaiserslautern, Kaiserslautern, Germany. BRUENE@rhrk.uni-kl.de
authors.forename: Bernhard
authors.initials: B
authors.lastname: Brüne
authors.forename: Jie
authors.initials: J
authors.lastname: Zhou
mesh_terms: D004268:DNA-Binding Proteins / Q000502:physiology*; D000860:Hypoxia / Q000378:metabolism*; D051793:Hypoxia-Inducible Factor 1; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D009569:Nitric Oxide / Q000378:metabolism*; D019001:Nitric Oxide Synthase / Q000378:metabolism / Q000502:physiology; D052247:Nitric Oxide Synthase Type II; D009687:Nuclear Proteins / Q000502:physiology*; D010100:Oxygen / Q000502:physiology*; D014157:Transcription Factors / Q000378:metabolism*
chemical_list: D004268:DNA-Binding Proteins; D051793:Hypoxia-Inducible Factor 1; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D009687:Nuclear Proteins; D014157:Transcription Factors; D009569:Nitric Oxide; D019001:Nitric Oxide Synthase; D052247:Nitric Oxide Synthase Type II; D010100:Oxygen