Click here to close
Hello! We notice that you are using Internet Explorer, which is not supported by Xenbase and may cause the site to display incorrectly.
We suggest using a current version of Chrome,
FireFox, or Safari.
A cluster of negative charges at the amino terminal tail of CFTR regulates ATP-dependent channel gating.
Fu J
,
Ji HL
,
Naren AP
,
Kirk KL
.
???displayArticle.abstract???
1. The cystic fibrosis transmembrane conductance regulator (CFTR) chloride channel is activated by protein kinase A (PKA) phosphorylation of its R domain and by ATP binding at its nucleotide-binding domains (NBDs). Here we investigated the functional role of a cluster of acidic residues in the amino terminal tail (N-tail) that also modulate CFTR channel gating by an unknown mechanism. 2. A disease-associated mutant that lacks one of these acidic residues (D58N CFTR) exhibited lower macroscopic currents in Xenopus oocytes and faster deactivation following washout of a cAMP -activating cocktail than wild-type CFTR. 3. In excised membrane patches D58N CFTR exhibited a two-fold reduction in single channel open probability due primarily to shortened open channel bursts. 4. Replacing this and two nearby acidic residues with alanines (D47A, E54A, D58A) also reduced channel activity, but had negligible effects on bulk PKA phosphorylation or on the ATP dependence of channel activation. 5. Conversely, the N-tail triple mutant exhibited a markedly inhibited response to AMP-PNP, a poorly hydrolysable ATP analogue that can nearly lock open the wild-type channel. The N-tail mutant had both a slower response to AMP-PNP (activation half-time of 140 +/- 20 s vs. 21 +/- 4 s for wild type) and a lower steady-state open probability following AMP-PNP addition (0.68 +/- 0.08 vs. 0.92 +/- 0.03 for wild type). 6. Introducing the N-tail mutations into K1250A CFTR, an NBD2 hydrolysis mutant that normally exhibits very long open channel bursts, destabilized the activity of this mutant as evidenced by decreased macroscopic currents and shortened open channel bursts. 7. We propose that this cluster of acidic residues modulates the stability of CFTR channel openings at a step that is downstream of ATP binding and upstream of ATP hydrolysis, probably at NBD2.
Abman,
Early bacteriologic, immunologic, and clinical courses of young infants with cystic fibrosis identified by neonatal screening.
1991, Pubmed
Abman,
Early bacteriologic, immunologic, and clinical courses of young infants with cystic fibrosis identified by neonatal screening.
1991,
Pubmed
Aleksandrov,
The non-hydrolytic pathway of cystic fibrosis transmembrane conductance regulator ion channel gating.
2000,
Pubmed
Anderson,
Nucleoside triphosphates are required to open the CFTR chloride channel.
1991,
Pubmed
Baukrowitz,
Coupling of CFTR Cl- channel gating to an ATP hydrolysis cycle.
1994,
Pubmed
Carson,
The two nucleotide-binding domains of cystic fibrosis transmembrane conductance regulator (CFTR) have distinct functions in controlling channel activity.
1995,
Pubmed
Chan,
Severed molecules functionally define the boundaries of the cystic fibrosis transmembrane conductance regulator's NH(2)-terminal nucleotide binding domain.
2000,
Pubmed
,
Xenbase
Cheng,
Defective intracellular transport and processing of CFTR is the molecular basis of most cystic fibrosis.
1990,
Pubmed
Cheng,
Phosphorylation of the R domain by cAMP-dependent protein kinase regulates the CFTR chloride channel.
1991,
Pubmed
Csanády,
Severed channels probe regulation of gating of cystic fibrosis transmembrane conductance regulator by its cytoplasmic domains.
2000,
Pubmed
,
Xenbase
De Braekeleer,
Mutations in the cystic fibrosis gene in men with congenital bilateral absence of the vas deferens.
1996,
Pubmed
Gabriel,
Cystic fibrosis heterozygote resistance to cholera toxin in the cystic fibrosis mouse model.
1994,
Pubmed
Gadsby,
Control of CFTR channel gating by phosphorylation and nucleotide hydrolysis.
1999,
Pubmed
Gunderson,
Conformational states of CFTR associated with channel gating: the role ATP binding and hydrolysis.
1995,
Pubmed
Hung,
Crystal structure of the ATP-binding subunit of an ABC transporter.
1998,
Pubmed
Hwang,
Regulation of the gating of cystic fibrosis transmembrane conductance regulator C1 channels by phosphorylation and ATP hydrolysis.
1994,
Pubmed
Hyde,
Structural model of ATP-binding proteins associated with cystic fibrosis, multidrug resistance and bacterial transport.
1990,
Pubmed
Ikuma,
Regulation of CFTR Cl- channel gating by ATP binding and hydrolysis.
2000,
Pubmed
Illek,
Defective function of the cystic fibrosis-causing missense mutation G551D is recovered by genistein.
1999,
Pubmed
Lu,
Cystic fibrosis transmembrane conductance regulator: the purified NBF1+R protein interacts with the purified NBF2 domain to form a stable NBF1+R/NBF2 complex while inducing a conformational change transmitted to the C-terminal region.
2000,
Pubmed
Mathews,
Dibasic protein kinase A sites regulate bursting rate and nucleotide sensitivity of the cystic fibrosis transmembrane conductance regulator chloride channel.
1998,
Pubmed
Mathews,
The CFTR chloride channel: nucleotide interactions and temperature-dependent gating.
1998,
Pubmed
Naren,
Syntaxin 1A is expressed in airway epithelial cells, where it modulates CFTR Cl(-) currents.
2000,
Pubmed
,
Xenbase
Naren,
Regulation of CFTR chloride channels by syntaxin and Munc18 isoforms.
1997,
Pubmed
,
Xenbase
Naren,
Syntaxin 1A inhibits CFTR chloride channels by means of domain-specific protein-protein interactions.
1998,
Pubmed
,
Xenbase
Naren,
CFTR chloride channel regulation by an interdomain interaction.
1999,
Pubmed
,
Xenbase
Neville,
Expression and characterization of the NBD1-R domain region of CFTR: evidence for subunit-subunit interactions.
1998,
Pubmed
Peters,
Syntaxin 1A inhibits regulated CFTR trafficking in xenopus oocytes.
1999,
Pubmed
,
Xenbase
Quinton,
Chloride impermeability in cystic fibrosis.
1983,
Pubmed
Ramjeesingh,
Walker mutations reveal loose relationship between catalytic and channel-gating activities of purified CFTR (cystic fibrosis transmembrane conductance regulator).
1999,
Pubmed
Riordan,
Identification of the cystic fibrosis gene: cloning and characterization of complementary DNA.
1989,
Pubmed
Sheppard,
Mutations in CFTR associated with mild-disease-form Cl- channels with altered pore properties.
1993,
Pubmed
Wilkinson,
CFTR: the nucleotide binding folds regulate the accessibility and stability of the activated state.
1996,
Pubmed
,
Xenbase
Wilkinson,
CFTR activation: additive effects of stimulatory and inhibitory phosphorylation sites in the R domain.
1997,
Pubmed
,
Xenbase
Winter,
Effect of ATP concentration on CFTR Cl- channels: a kinetic analysis of channel regulation.
1994,
Pubmed
Zielenski,
Cystic fibrosis: genotypic and phenotypic variations.
1995,
Pubmed
