Function of the second nucleotide-binding fold in the CFTR chloride channel

FEBS Lett. 1999 Oct 8;459(2):177-85. doi: 10.1016/s0014-5793(99)01230-2.

Abstract

To test the role of nucleotide-binding fold (NBF) 2 and its interaction with the regulatory (R) domain in the function of the cystic fibrosis transmembrane conductance regulator (CFTR) channel, we used three deletion mutants of CFTR: DeltaR(708-835), DeltaNBF2(1185-1349) and DeltaR-DeltaNBF2. In lipid bilayers, DeltaNBF2 channel activity is ATP- and cAMP-dependent protein kinase (PKA)-dependent, but unlike wild-type (wt) CFTR, it displays a reduced activity and insensitivity to 5'-adenylylimidodiphosphate (AMP-PNP). Both DeltaR and DeltaR-DeltaNBF2 channels are PKA-independent, but DeltaR activity is reduced whereas DeltaR-DeltaNBF2 activity is increased. Deletion of NBF2 from CFTR affects protein trafficking and channel gating kinetics. The data suggest that NBF2 could have inhibitory and stimulatory roles in CFTR activity by interaction with NBF1 directly or indirectly via the R domain.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adenosine Triphosphate / metabolism*
  • Cells, Cultured
  • Cystic Fibrosis Transmembrane Conductance Regulator / chemistry
  • Cystic Fibrosis Transmembrane Conductance Regulator / genetics
  • Cystic Fibrosis Transmembrane Conductance Regulator / metabolism*
  • Gene Deletion
  • Humans
  • Kinetics
  • Lipid Bilayers / metabolism
  • Protein Conformation
  • Protein Folding*
  • Subcellular Fractions / metabolism
  • Transfection

Substances

  • CFTR protein, human
  • Lipid Bilayers
  • Cystic Fibrosis Transmembrane Conductance Regulator
  • Adenosine Triphosphate