Jonathan Allen Cohn, MD

Professor of Medicine
Associate Professor of Cell Biology
Professor in Pediatrics
Campus mail DUMC Box 3256, Durham, NC 27710
Phone (919) 684-6879
Email address jonathan.cohn@duke.edu

In many epithelial tissues, the protein mainly responsible for controlling transepithelial fluid movement is the the cystic fibrosis transmembrane conductance regulator (CFTR). CFTR was originally identified as the protein product of the gene causing cystic fibrosis (CF). CFTR functions as a chloride channel regulated by protein kinase A (PKA). This laboratory is studying the role and regulation of CFTR. One project focuses on how PKA acts on CFTR. In this project, recombinant peptide models are being used to model the cytoplasmic domains of CFTR responsible for activating the protein's chloride's chloride channel function. Site-directed mutagenesis is being used to produce modified peptides to study how different individual serine phosphoryation contribute to CFTR regulation. A second project concerns DF508, the most common mutation among patients with CF. This mutation affects CFTR function by preventing normal folding and intracellular trafficking of the newly synthesized mutant protein. This project is examining the mislocalization of DF508-CFTR in tissues and cell lines with the long term goal of developing strategies to prevent the mutant protein from mislocalizing. A third project concerns the role of CFTR in chronic pancreatitic diseases. Emerging data about the role of CFTR during normal pancreatic secretion suggests that dysfunction of this protein may lead to pancreatic diseases such as chronic pancreatitis and pancreatic cancer. Patients with these chronic pancreatic diseases are being tested for CFTR mutations and for evidence of defective CFTR function.

Education and Training

  • Fellow in Gastroenterology, Medicine, Yale University, 1981 - 1984
  • Medical Resident, Medicine, University of California San Francisco, School of Medicine, 1980 - 1981
  • Medical Resident, Medicine, University of Alabama Birmingham, 1978 - 1980
  • M.D., Cornell University, 1978

Publications

Torres, R. J., G. A. Altenberg, J. A. Cohn, and L. Reuss. “Polarized expression of cAMP-activated chloride channels in isolated epithelial cells.” American Journal of Physiology Cell Physiology 271, no. 5 (November 1, 1996): C1574–82.

Scholars@Duke

Stutts, M. J., C. M. Canessa, J. C. Olsen, M. Hamrick, J. A. Cohn, B. C. Rossier, and R. C. Boucher. “CFTR as a cAMP-dependent regulator of sodium channels.” Science 269, no. 5225 (August 11, 1995): 847–50. https://doi.org/10.1126/science.7543698.

PMID
7543698
Full Text

Chen, J., J. A. Cohn, and L. J. Mandel. “Dephosphorylation of ezrin as an early event in renal microvillar breakdown and anoxic injury.” Proc Natl Acad Sci U S A 92, no. 16 (August 1, 1995): 7495–99. https://doi.org/10.1073/pnas.92.16.7495.

PMID
7638219
Full Text

Borchardt, R. A., A. M. Kaz, J. Kole, and J. A. Cohn. “Protein kinase A and protein kinase C phosphorylate distinct serine residues in CFTR.” Gastroenterology 108, no. 4 (April 1995): A275–A275. https://doi.org/10.1016/0016-5085(95)23760-7.

Full Text

Smit, L. S., T. V. Strong, D. J. Wilkinson, M. Macek, M. K. Mansoura, D. L. Wood, J. L. Cole, G. R. Cutting, J. A. Cohn, and D. C. Dawson. “Missense mutation (G480C) in the CFTR gene associated with protein mislocalization but normal chloride channel activity.” Hum Mol Genet 4, no. 2 (February 1995): 269–73. https://doi.org/10.1093/hmg/4.2.269.

PMID
7757078
Full Text

ERNST, S. A., K. M. CRAWFORD, M. A. POST, and J. A. COHN. “SALT STRESS INCREASES ABUNDANCE AND GLYCOSYLATION OF CFTR LOCALIZED AT APICAL SURFACES OF SALT-GLAND SECRETORY-CELLS.” American Journal of Physiology Cell Physiology 267, no. 4 (October 1, 1994): C990–1001.

Scholars@Duke

Ernst, S. A., K. M. Crawford, M. A. Post, and J. A. Cohn. “Salt stress increases abundance and glycosylation of CFTR localized at apical surfaces of salt gland secretory cells.” Am J Physiol 267, no. 4 Pt 1 (October 1994): C990-1001. https://doi.org/10.1152/ajpcell.1994.267.4.C990.

PMID
7524345
Full Text

COHN, J. A., T. D. NGUYEN, A. M. KAZ, and J. KOLE. “THE CYSTIC-FIBROSIS TRANSMEMBRANE CONDUCTANCE REGULATOR IN RAT ENTEROCYTES.” In Gastroenterology, 106:A229–A229. W B SAUNDERS CO, 1994.

Scholars@Duke

Bradbury, N. A., J. A. Cohn, C. J. Venglarik, and R. J. Bridges. “Biochemical and biophysical identification of cystic fibrosis transmembrane conductance regulator chloride channels as components of endocytic clathrin-coated vesicles.” J Biol Chem 269, no. 11 (March 18, 1994): 8296–8302.

PMID
7510684
Scholars@Duke

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