Evidence for direct CFTR inhibition by CFTRinh-172 based on Arg347 mutagenesis

Emanuela Caci, Antonella Caputo, Alexandre Hinzpeter, Nicole Arous, Pascale Fanen, Nitin Sonawane, A. S. Verkman, Roberto Ravazzolo, Olga Zegarra-Moran, Luis J V Galietta

Research output: Contribution to journalArticlepeer-review

Abstract

CFTR (cystic fibrosis transmembrane conductance regulator) is an epithelial Cl- channel inhibited with high affinity and selectivity by the thiazolidinone compound CFTRinh-172. In the present study, we provide evidence that CFTRinh-172 acts directly on the CFTR. We introduced mutations in amino acid residues of the sixth transmembrane helix of the CFTR protein, a domain that has an important role in the formation of the channel pore. Basic and hydrophilic amino acids at positions 334-352 were replaced with alanine residues and the sensitivity to CFTRinh-172 was assessed using functional assays. We found that an arginine-to-alanine change at position 347 reduced the inhibitory potency of CFTRinh-172 by 20-30-fold. Mutagenesis of Arg347 to other amino acids also decreased the inhibitory potency, with aspartate producing near total loss of CFTR inh-172 activity. The results of the present study provide evidence that CFTRinh-172 interacts directly with CFTR, and that Arg 347 is important for the interaction.

Original languageEnglish
Pages (from-to)135-142
Number of pages8
JournalBiochemical Journal
Volume413
Issue number1
DOIs
Publication statusPublished - Jul 1 2008

Keywords

  • Channel blocker
  • Chloride channel
  • Cystic fibrosis
  • Cystic fibrosis transmembrane conductance regulator (CFTR)
  • Mutagenesis

ASJC Scopus subject areas

  • Biochemistry
  • Medicine(all)

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