1. Department of Cell and Developmental Biology and Cystic Fibrosis Research Center, University of North Carolina, Chapel Hill, NC 27599, USA
2. Department of Biochemistry and Molecular Biology, Mayo Clinic College of Medicine, Rochester, MN 55905, USA
3. Department of Biochemistry and Molecular Biology, Mayo Clinic College of Medicine, Scottsdale, AZ 85259, USA
4. Department of Biochemistry and Biophysics and Cystic Fibrosis Research Center, University of North Carolina, Chapel Hill, NC 27599, USA