Written by Talent KAS

Related Topics: Awards & Honours, Science & Technology


  • The Nobel Prize for Physiology or Medicine 2019 has been awarded to three scientists for discovery of how cells sense and adapt to oxygen availability.
  • The three scientists will share the Nobel Prize sum of nine million Swedish kronor or about 9 Lakh 14 thousand US dollars.

The Nobel Winners

  • William Kaelin of Harvard University
  • Peter Ratcliffe of Oxford University
  • Gregg Semenza of Johns Hopkins University

Award Winning Discovery

  • They have been jointly awarded the Nobel for their work of identifying molecular machinery that regulates the activity of genes in response to varying levels of oxygen.
  • The fundamental importance of oxygen has been understood for centuries, but how cells adapt to changes in oxygen levels has long been unknown.
  • The scientists discovered the molecular switch that controls how our cells respond to varying levels of oxygen in the surroundings.
  • Cells need oxygen to survive, but they don’t have a steady supply – levels vary at different altitudes, but also during exercise.
  • Oxygen supply is also disrupted when the blood supply is cut off in diseases like cancer and stroke.
  • To understand how cells respond to these variations, Gregg Semenza studied the gene for Erythropoietin (EPO), a hormone that produces more red blood cells when oxygen levels are running low.
  • Semenza found that the increase in EPO was due to a specific region of the gene and identified two proteins that essentially control how the gene works.
  • One of these was found to respond to oxygen levels – it is present when levels are low, but disappears when there is plenty of oxygen around.
  • Ratcliffe and Kaelins identified another protein, called VHL that is responsible for destroying that protein when oxygen levels are high.
  • Together, the work of the three scientists reveals a molecular switch for responding to oxygen levels.


  • The molecular switch is important in understanding and treating disorders like anaemia, which results in low oxygen levels, and diseases like stroke, heart attack and cancer, which can also shut off the blood oxygen supply to cells.
  • The discoveries made by the three scientists “have fundamental importance for physiology and have paved the way for promising new strategies to fight anemia, cancer and many other diseases.”
[Source: The Hindu, New Scientist]

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Talent KAS

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