Red blood cells adapt to low oxygen by reorganizing proteins

Researchers at the University of Colorado Anschutz have discovered that red blood cells are far more complex than previously understood. While traditionally viewed as passive sacs of hemoglobin, a new study published in the journal Sang reveals that these cells can rapidly reorganize their existing chemical machinery to adapt to fluctuating oxygen levels.

By identifying 3,775 proteins within ultra-pure human red blood cells, scientists mapped thousands of physical interactions that change when oxygen availability drops. Because red blood cells lack a nucleus, they cannot synthesize new proteins to respond to environmental changes. Instead, they utilize a reversible mechanism that acts like a switch to redistribute existing proteins.

A central component of this network is the Band 3 protein, located in the cell membrane. The study found that under low-oxygen conditions, the enzyme BLVRB stops associating with Band 3, altering its contacts with deoxyhemoglobin. This reorganization helps the cell adjust energy production through glycolysis and increases the synthesis of 2,3-bisphosphoglycerate, a molecule that facilitates oxygen release into tissues. These findings provide critical insights into how the body manages high altitudes, intense exercise, and pathological hypoxia.