Protein phosphatase 2C dephosphorylates and inactivates cystic fibrosis transmembrane conductance regulator.

ABSTRACT: cAMP-dependent phosphorylation activates the cystic fibrosis transmembrane conductance regulator (CFTR) in epithelia. However, the protein phosphatase (PP) that dephosphorylates and inactivates CFTR in airway and intestinal epithelia, two major sites of disease, is not certain. We found that in airway and colonic epithelia, neither okadaic acid nor FK506 prevented inactivation of CFTR when cAMP was removed. These results suggested that a phosphatase distinct from PP1, PP2A, and PP2B was responsible. Because PP2C is insensitive to these inhibitors, we tested the hypothesis that it regulates CFTR. We found that PP2Calpha is expressed in airway and T84 intestinal epithelia. To test its activity on CFTR, we generated recombinant human PP2Calpha and found that it dephosphorylated CFTR and an R

SUBMITTER: Travis SM 

PROVIDER: S-EPMC23594 | biostudies-literature | 1997 Sep

REPOSITORIES: biostudies-literature