NMR evidence for differential phosphorylation-dependent interactions in WT and DF508 CFTR

Voula Kanelis, Rhea P. Hudson, Patrick H. Thibodeau, Philip J. Thomas, Julie D. Forman-Kay

Research output: Contribution to journalArticle

67 Scopus citations

Abstract

The most common cystic fibrosis (CF)-causing mutation in the cystic fibrosis transmembrane conductance regulator (CFTR) is deletion of Phe508 (DF508) in the first of two nucleotide-binding domains (NBDs). Nucleotide binding and hydrolysis at the NBDs and phosphorylation of the regulatory (R) region are required for gating of CFTR chloride channel activity. We report NMR studies of wild-type and DF508 murine CFTR NBD1 with the C-terminal regulatory extension (RE), which contains residues of the R region. Interactions of the wild-type NBD1 core with the phosphoregulatory regions, the regulatory insertion (RI) and RE, are disrupted upon phosphorylation, exposing a potential binding site for the first coupling helix of the N-terminal intracellular domain (ICD). Phosphorylation of DF508 NBD1 does not as effectively disrupt interactions with the phosphoregulatory regions, which, along with other structural differences, leads to decreased binding of the first coupling helix. These results provide a structural basis by which phosphorylation of CFTR may affect the channel gating of full-length CFTR and expand our understanding of the molecular basis of the DF508 defect.

Original languageEnglish (US)
Pages (from-to)263-277
Number of pages15
JournalEMBO Journal
Volume29
Issue number1
DOIs
StatePublished - Jan 6 2010

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Keywords

  • CFTR
  • Coupling helix 1
  • NBD1
  • NMR spectroscopy
  • Phosphorylation

ASJC Scopus subject areas

  • Neuroscience(all)
  • Molecular Biology
  • Biochemistry, Genetics and Molecular Biology(all)
  • Immunology and Microbiology(all)

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