Cystic fibrosis: yeast study may address root cause

29 Aug

Yeast is helping to tackle the root cause of cystic fibrosis – a disease that results

from faulty ion channels. A new study shows how a small molecule can take the place of a missing

protein in yeast cells with faulty ion channels, enabling them to work again.

mother and child with doctor
Most cases of cystic fibrosis are diagnosed by the age of 2.

The study, by researchers from the University of Illinois at Urbana-Champaign, is published in

the Journal of the American Chemical Society.

All organisms – from microbes to humans – rely on protein pumps and channels that transport ions

across the cell membrane. Faulty ion channels in cells underlie many currently incurable human


Cystic fibrosis is caused by a genetic mutation that affects some of the proteins that

make up ion channels, causing them to malfunction. The result is a thick build up of mucus in the

lungs and other organs, making breathing difficult.

While treatments for cystic fibrosis exist, they do not fix the underlying cause. Treatments

include inhalants, enzyme supplements and clearing the airways, which can usually only be done

with help.

Yeast is a useful organism for researching human health and disease because yeast cells are

very similar to human cells. On two occasions, yeast has featured in studies that have won Nobel

prizes (one in 2001, the other in 2009) for their work on human cells.

The new study describes how a small molecule can take the place of a missing protein

to restore the type of ion channel function that is missing in people with cystic fibrosis and

similar diseases. The molecule – amphotericin B – was originally extracted from bacteria and is used to

treat fungal infections.

The small molecule caused deficient yeast to grow nearly as well as normal yeast

The team tested the small molecule at low doses in a strain of yeast that cannot grow because

it has faulty ion channels.

Fast facts about cystic fibrosis

  • People with cystic fibrosis have inherited two copies of the defective CF gene
  • About 70,000 people worldwide are living with cystic fibrosis
  • Most cases are diagnosed by the age of 2.

Learn more about cystic fibrosis

When they added the molecule, the researchers found the yeast grew nearly as well as a normal

strain that they used as a control. They note:

“Here we report vigorous and sustainable restoration of yeast cell growth by

replacing missing protein ion transporters with imperfect small molecule


The authors say more research is needed to confirm whether the small molecule will work in

human diseases like cystic fibrosis. In the meantime, however, they conclude that their study provides a “framework for

pursuing such a therapeutic strategy.”

People with cystic fibrosis are at greater risk of lung infection because the thick, sticky

mucus that builds up in the lungs allows germs to thrive and multiply.

Earlier this year, Medical News Today reported how researchers are reaching a better

understanding of infections in cystic fibrosis. A small study

of children with the disease reveals that the microorganisms that infect people with cystic

fibrosis can survive on little to no oxygen.

Written by Catharine Paddock PhD

Copyright: Medical News Today

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