Conformational change opening the CFTR chloride channel pore coupled to ATP-dependent gating

Wuyang Wang, Paul Linsdell

Producción científica: Contribución a una revistaArtículorevisión exhaustiva

18 Citas (Scopus)

Resumen

Opening and closing of the cystic fibrosis transmembrane conductance regulator (CFTR) chloride channel are controlled by ATP binding and hydrolysis by its nucleotide binding domains (NBDs). This is presumed to control opening of a single "gate" within the permeation pathway, however, the location of such a gate has not been described. We used patch clamp recording to monitor access of cytosolic cysteine reactive reagents to cysteines introduced into different transmembrane (TM) regions in a cysteine-less form of CFTR. The rate of modification of Q98C (TM1) and I344C (TM6) by both [2-sulfonatoethyl] methanethiosulfonate (MTSES) and permeant Au(CN) 2 - ions was reduced when ATP concentration was reduced from 1 mM to 10 μM, and modification by MTSES was accelerated when 2 mM pyrophosphate was applied to prevent channel closure. Modification of K95C (TM1) and V345C (TM6) was not affected by these manoeuvres. We also manipulated gating by introducing the mutations K464A (in NBD1) and E1371Q (in NBD2). The rate of modification of Q98C and I344C by both MTSES and Au(CN) 2 - was decreased by K464A and increased by E1371Q, whereas modification of K95C and V345C was not affected. These results suggest that access from the cytoplasm to K95 and V345 is similar in open and closed channels. In contrast, modifying ATP-dependent channel gating alters access to Q98 and I344, located further into the pore. We propose that ATP-dependent gating of CFTR is associated with the opening and closing of a gate within the permeation pathway at the level of these pore-lining amino acids.

Idioma originalEnglish
Páginas (desde-hasta)851-860
Número de páginas10
PublicaciónBiochimica et Biophysica Acta - Biomembranes
Volumen1818
N.º3
DOI
EstadoPublished - mar. 2012

Nota bibliográfica

Funding Information:
Supported by the Canadian Institutes of Health Research . W. Wang is a Cystic Fibrosis Canada Postdoctoral Fellow.

ASJC Scopus Subject Areas

  • Biophysics
  • Biochemistry
  • Cell Biology

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