Hypoxia inducible factor
Hypoxia Inducible Factor (HIF) is a heterodimeric transcription factor which responds to the relative lowering of the oxygen concentration in a cell (hypoxia)[1].
Hypoxia can be defined as a lowering of oxygen levels compared to sea levels (~20.9%)
HIFs come in two flavours: HIF-α (HIF-1α, HIF-2α, HIF-3α) and HIF-1β.
Under normal oxygen levels, HIF-1α is constantly made and degraded via ubiquitination.
However, when oxygen levels are low (hypoxia) HIF-1α can escape this translational block so that it’s no longer degraded and is still being made in hypoxia.
As a result, HIF-1α is stabilsed and able to dimerise with HIF-1β to activate target gene expression via recruitment of co-factors[2].
Reference
- ↑ Jennifer E. Ziello, Y. (2017). Hypoxia-Inducible Factor (HIF)-1 Regulatory Pathway and its Potential for Therapeutic Intervention in Malignancy and Ischemia. [online] PubMed Central (PMC). Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2140184/ [Accessed 20 Oct. 2017]
- ↑ Kenneth , N.S, Rocha, S. Regulation of gene expression by hypoxia. Biochemical journal. 2008;141(1): 19-29.