HIF1B

HIF1B, or hypoxia-inducible factor 1-beta, is a gene located on the long arm of chromosome 19 (19p13.3) in humans. It encodes a subunit of the hypoxia-inducible factor 1 (HIF-1) transcription factor complex, which plays a critical role in cellular responses to low oxygen levels (hypoxia). HIF-1 is a heterodimeric protein composed of two subunits: HIF-1α and HIF-1β. While HIF-1α is regulated by oxygen availability, HIF-1β is constitutively expressed and serves as a stable partner for HIF-1α under both normoxic and hypoxic conditions.

The HIF-1 complex regulates the transcription of numerous genes involved in adaptive responses to hypoxia, including those related to angiogenesis (formation of new blood vessels), erythropoiesis (red blood cell production), glycolysis, and cellular survival. By activating these pathways, HIF-1 helps maintain tissue oxygenation and energy production under low-oxygen conditions.

Mutations or dysregulation of HIF1B have been implicated in various diseases, including cancer. For instance, certain genetic variations in HIF1B have been associated with an increased risk of colorectal cancer and other malignancies, though the precise mechanisms remain under investigation. Additionally, studies suggest a potential link between HIF1B and conditions such as obesity and metabolic disorders, though further research is needed to clarify these associations.

HIF1B is highly conserved across species, indicating its fundamental biological importance. Its expression is detected in nearly all tissues, with particularly high levels in the brain, heart, and kidneys. The gene spans approximately 10 kilobases and contains 12 exons, encoding a protein of 789 amino acids. Research into HIF1B continues to explore its role in physiology and pathology, offering potential insights for therapeutic interventions in hypoxia-related disorders.