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Updated: Mar 2, 2026
Functional Reconstitution and Channel Activity Measurements of Purified Wildtype and Mutant CFTR Protein
Published on: March 9, 2015
CFTR structure and function: is there a role in the kidney?
J Souza-Menezes1, M M Morales2,3
1Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Macaé, Brazil.
Abstract:
Cystic fibrosis (CF) is a lethal autosomal recessive genetic disease caused by mutations in the CF transmembrane conductance regulator (CFTR). Mutations in the CFTR gene may result in a defective protein processing that leads to changes in function and regulation of this chloride channel. Despite of the expression of CFTR in the kidney, patients with CF do not present major renal dysfunction, but it is known that both the urinary excretion of proteins and renal capacity to concentrate and dilute urine are altered in these patients. CFTR mRNA is expressed in all nephron segments of rat and human, and this abundance is more prominent in renal cortex and outer medulla renal areas. CFTR protein was detected in apical surface of both proximal and distal tubules of rat kidney but not in the outer medullary collecting ducts. Studies have demonstrated that CFTR does not only transport Cl- but also ATP. ATP transport by CFTR could be involved in the control of other ion transporters such as Na+ (ENaC) and K+ (renal outer medullary potassium) channels, especially in TAL and CCD. In the kidney, CFTR also might be involved in the endocytosis of low-molecular-weight proteins by proximal tubules. This review is focused on the CFTR function and structure, its role in the renal physiology, and its modulation by hormones involved in the control of extracellular fluid volume.
Insights
Cystic fibrosis (CF) affects the kidney despite normal function, altering urine concentration and protein excretion. The CF transmembrane conductance regulator (CFTR) protein
Area of Science:
- Nephrology
- Genetics
- Molecular Biology
Background:
- Cystic fibrosis (CF) is a genetic disorder caused by CF transmembrane conductance regulator (CFTR) mutations.
- CFTR is expressed in the kidney, but major renal dysfunction is not typical in CF patients.
- However, altered urinary protein excretion and urine concentrating/diluting capacity are observed in CF.
Purpose of the Study:
- To review the structure and function of CFTR.
- To elucidate the role of CFTR in renal physiology.
- To explore CFTR modulation by hormones regulating extracellular fluid volume.
Main Methods:
- Review of existing literature on CFTR in renal physiology.
- Analysis of studies on CFTR expression and function in kidney tissues.
- Examination of CFTR's role in ion transport and protein handling in nephrons.
Main Results:
- CFTR mRNA is present in all nephron segments, with higher abundance in the renal cortex and outer medulla.
- CFTR protein is detected on the apical surface of proximal and distal tubules in rat kidneys.
- CFTR transports both Cl- and ATP, potentially influencing Na+ and K+ channels and protein endocytosis.
Conclusions:
- CFTR plays a significant role in renal physiology beyond chloride transport.
- Its function in ion transport and potential involvement in protein handling are critical for kidney function.
- Understanding CFTR's renal role is essential for managing CF patients and exploring therapeutic targets.
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