Imaging CFTR in its native environment.

Area of Science:

• Biophysics
• Cell Biology
• Molecular Medicine

Background:

• The cystic fibrosis transmembrane conductance regulator (CFTR) is vital for epithelial salt and water balance.
• Mutations in CFTR cause cystic fibrosis (CF), a common lethal genetic disorder.
• Studying CFTR at the single-molecule level in its native environment is crucial.

Purpose of the Study:

• To visualize and quantify CFTR distribution and organization in cell membranes using atomic force microscopy (AFM).
• To investigate CFTR dynamics and structure at the single-molecule level.
• To compare CFTR in healthy individuals, CF patients, and CFTR-expressing oocytes.

Main Methods:

• Application of atomic force microscopy (AFM) on isolated plasma membranes.
• High-resolution scans of immunogold-labeled CFTR.
• Studies on CFTR-expressing oocytes.

Main Results:

• Human red blood cells show CFTR distribution similar to epithelial cells.
• CF patients exhibit a significantly reduced number of CFTR proteins.
• Cyclic adenosine monophosphate (cAMP) induces CFTR insertion and formation of heteromeric structures.
• CFTR was identified as a tail-to-tail dimer with a central pore.

Conclusions:

• AFM on isolated plasma membranes enables quantification and localization of membrane proteins like CFTR.
• AFM provides insights into CFTR dynamics at the single-molecule level.
• This method aids in understanding CFTR in health and disease states.