Ion transport defects cause cystic fibrosis

The plasma membrane is one of the most critically important structures in our body. The plasma membrane protects our cells, allows for intercellular communication and intracellular signaling, and maintains homeostasis by controlling transport in and out of the cell.

When transport is disrupted in the plasma membrane, serious medical complications can occur. Cystic fibrosis is an autosomal recessive genetic disorder that is found in 70,000 people worldwide. Cystic fibrosis is caused by a mutation in the protein cystic fibrosis transmembrane conductance regulator (CFTR) gene. CFTR regulates chloride transport in the epithelium, particularly in the lungs, but also the liver, intestine, and pancreas, and is important for creating mucus, sweat, and digestive tract fluids. In cystic fibrosis, CFTR’s regulation of these ions is abnormal, disrupting salt and water transport in and out of cells. This leads to a build-up of thick mucus in the lungs and digestive tract. People who have cystic fibrosis have trouble breathing and have frequent lung and sinus infections amongst other complications.