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Hypoxia-inducible factor 1 proteomics and diving adaptations in ringed seal
Peter Johnson1, Robert Elsner, Tania Zenteno-Savín
1Department of Biomedical Sciences, Ohio University, Athens, OH 45701, USA.
Free Radical Biology & Medicine
|June 21, 2005
Summary
Ringed seal (Phoca hispida) hypoxia-inducible factor 1alpha (HIF-1alpha) protein is present at high levels and may protect against diving oxidative stress. Its function is not due to pVHL absence but likely involves transcriptional activation.
Area of Science:
- Marine Mammal Physiology
- Molecular Biology
- Biochemistry
Background:
- Hypoxia-inducible factor 1alpha (HIF-1alpha) plays a crucial role in cellular oxygen homeostasis.
- Ringed seals (Phoca hispida) exhibit high HIF-1alpha levels, prompting investigation into its function, particularly concerning diving adaptations and oxidative stress.
Purpose of the Study:
- To investigate the amino acid sequence of ringed seal HIF-1alpha.
- To understand the reasons for high HIF-1alpha levels in seal tissues.
- To explore the potential role of HIF-1alpha in protecting against diving-related oxidative damage.
Main Methods:
- DNA sequence analysis of the single-copy HIF-1alpha gene.
- Comparison of functional domains (bHLH/PAS, TAD, ODD) with terrestrial mammals.
- Assessment of protein-protein interactions (HIF-1beta, DNA, coactivators, pVHL).
Main Results:
- Seal HIF-1alpha shares similarities with terrestrial mammals but has sequence differences in the ODD domain.
- Seal HIF-1alpha can bind to HIF-1beta, DNA, transcriptional coactivators, and von Hippel-Lindau protein (pVHL).
- High HIF-1alpha levels in seal tissues are not due to the absence of pVHL, which is present in all examined tissues.
Conclusions:
- Seal HIF-1alpha likely functions as a transcriptional activator.
- Its presence is probably not caused by an inability to interact with pVHL.
- Seal HIF-1alpha may protect against ischemia/reperfusion oxidative stress and aid lung reinflation post-diving.