Multiple membrane-cytoplasmic domain contacts in the cystic fibrosis transmembrane conductance regulator (CFTR) mediate regulation of channel gating

Lihua He, Andrei A. Aleksandrov, Adrian W.R. Serohijos, Tamás Hegedus, Luba A. Aleksandrov, Liying Cui, Nikolay V. Dokholyan, John R. Riordan

Research output: Contribution to journalArticle

92 Citations (Scopus)

Abstract

The cystic fibrosis transmembrane conductance regulator (CFTR) is a unique ATP-binding cassette (ABC) ion channel mutated in patients with cystic fibrosis. The most common mutation, deletion of phenylalanine 508 (ΔF508) and many other disease-associated mutations occur in the nucleotide binding domains (NBD) and the cytoplasmic loops (CL) of the membrane-spanning domains (MSD). A recently constructed computational model of the CFTR three-dimensional structure, supported by experimental data (Serohijos, A. W., Hegedus, T., Aleksandrov, A. A., He, L., Cui, L., Dokholyan, N. V., and Riordan, J. R. (2008) Proc. Natl. Acad. Sci. U. S. A. 105, 3256-3261) revealed that several of these mutations including ΔF508 disrupted interfaces between these domains. Here we have used cysteine cross-linking experiments to verify all NBD/CL interfaces predicted by the structural model and observed that their cross-linking has a variety of different effects on channel gating. The interdomain contacts comprise aromatic clusters important for stabilization of the interfaces and also involve the Q-loops and X-loops that are in close proximity to the ATP binding sites. Cross-linking of all domain-swapping contacts between NBDs and MSD cytoplasmic loops in opposite halves of the protein rapidly and reversibly arrest single channel gating while those in the same halves have lesser impact. These results reinforce the idea that mediation of regulatory signals between cytoplasmic- and membrane-integrated domains of the CFTR channel apparently relies on an array of precise but highly dynamic interdomain structural joints.

Original languageEnglish
Pages (from-to)26383-26390
Number of pages8
JournalJournal of Biological Chemistry
Volume283
Issue number39
DOIs
Publication statusPublished - Sep 26 2008

ASJC Scopus subject areas

  • Biochemistry
  • Molecular Biology
  • Cell Biology

Fingerprint Dive into the research topics of 'Multiple membrane-cytoplasmic domain contacts in the cystic fibrosis transmembrane conductance regulator (CFTR) mediate regulation of channel gating'. Together they form a unique fingerprint.

  • Cite this