Interaction of nucleotides with membrane-associated cystic fibrosis transmembrane conductance regulator

Sue M Travis; Mark R Carson; Dana R Ries; Michael J Welsh

doi:10.1016/S0021-9258(18)82259-1

Back

Interaction of nucleotides with membrane-associated cystic fibrosis transmembrane conductance regulator

Journal article

Open access

Peer reviewed

Interaction of nucleotides with membrane-associated cystic fibrosis transmembrane conductance regulator

Sue M Travis, Mark R Carson, Dana R Ries and Michael J Welsh

The Journal of biological chemistry, Vol.268(21), pp.15336-15339

07/25/1993

DOI: 10.1016/S0021-9258(18)82259-1

PMID: 7687995

Files and links (1)

url

https://doi.org/10.1016/S0021-9258(18)82259-1View

Published (Version of record) Open Access

Abstract

Cystic fibrosis transmembrane conductance regulator (CFTR) is a Cl- channel that is regulated by cytosolic nucleotides and by cAMP-dependent phosphorylation. In excised membrane patches, CFTR Cl- channel activity requires hydrolyzable nucleotides and Mg2+, and is inhibited by ADP. We examined the interactions between CFTR and nucleotides using 8-azidoadenosine 5'-triphosphate (8-N3-ATP), a photoactivatable ATP analog. Because CFTR functions as a membrane ion channel, we studied CFTR in membranes of Sf9 insect cells. We found that [alpha-32P]8-N3ATP specifically photolabeled CFTR, with half-maximal labeling at 10 microM 8-N3ATP in the presence of Mg2+ and 100 microM in the absence of Mg2+. The 8-N3ATP also substituted for ATP in activating CFTR Cl- channels, indicating that it interacts with the active site(s). Both ATP and GTP prevented photolabeling with half-maximal inhibition at 1 mM. ADP and adenyl-5'-yl imidodiphosphate (AMP-PNP) prevented photolabeling but at much higher concentrations, whereas AMP did not inhibit photolabeling at concentrations of up to 100 mM. Phosphorylation of CFTR was not a prerequisite for nucleotide binding. These results demonstrate that CFTR interacts directly with nucleotides at concentrations that regulate CFTR Cl- channel activity.

Phosphorylation

Affinity Labels

Protein Kinases - metabolism

Cystic Fibrosis - metabolism

Membrane Proteins - genetics

Humans

Cells, Cultured

Baculoviridae - genetics

Magnesium - metabolism

Moths

Adenosine Triphosphate - analogs & derivatives

Cystic Fibrosis Transmembrane Conductance Regulator

Azides

Animals

Chloride Channels

Adenine Nucleotides - metabolism

Cloning, Molecular

Membrane Proteins - metabolism

Binding Sites

Details

Title: Subtitle: Interaction of nucleotides with membrane-associated cystic fibrosis transmembrane conductance regulator
Creators: Sue M Travis - Howard Hughes Medical Institute, Department of Internal Medicine, University of Iowa, College of Medicine, Iowa City 52242
Mark R Carson
Dana R Ries
Michael J Welsh
Resource Type: Journal article
Publication Details: The Journal of biological chemistry, Vol.268(21), pp.15336-15339
DOI: 10.1016/S0021-9258(18)82259-1
PMID: 7687995
NLM abbreviation: J Biol Chem
ISSN: 0021-9258
eISSN: 1083-351X
Publisher: United States
Language: English
Date published: 07/25/1993
Academic Unit: Neurology; Molecular Physiology and Biophysics; Neurosurgery; Internal Medicine
Record Identifier: 9984020869502771

Metrics

11 Record Views

58 Times Cited - Web of Science