Monitoring of cellular responses to hypoxia.
Oxygen is essential for survival of aerobic organisms. Sensing changes in the environmental oxygen concentration and appropriate adaptation to such changes are essential for organisms to survive. Hypoxia inducible factor 1 (HIF-1) is the key transcription factor in controlling the expression of oxygen-dependent genes required for this adaptation. HIF-1 is a heterodimer of an oxygen dependent alpha-subunit and constitutive beta-subunit. Abundance and activity of HIF-1 is controlled by post-translational hydroxylation. Microscopic analysis of the assembly and activation process of HIF-1 has become an important tool to better understand HIF-1 regulation. Confocal laser microscopy provides exact images of HIF-1alpha that is translocated into the nucleus under hypoxia and its disappearance upon reoxygenation. To exactly follow the protein-protein interaction during the assembly process of HIF-1, both subunits were labeled by fusing them to fluorescent proteins. Fluorescence resonance energy transfer (FRET) was used to determine the interaction of both subunits in living cells by confocal microscopy.
Wotzlaw
Christoph
C
Institut für Physiologie, Universität Duisburg-Essen, Essen, Germany.
Fandrey
Joachim
J
D000818:Animals; D002417:Cattle; D015687:Cell Hypoxia; D045744:Cell Line, Tumor; D002467:Cell Nucleus / Q000378:metabolism; D002470:Cell Survival; D031541:Fluorescence Resonance Energy Transfer; D005455:Fluorescent Antibody Technique; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000737:chemistry / Q000378:metabolism; D051379:Mice; D018613:Microscopy, Confocal; D055503:Protein Multimerization; D020836:Protein Structure, Quaternary
D051795:Hypoxia-Inducible Factor 1, alpha Subunit