CFTR activation: additive effects of stimulatory and inhibitory phosphorylation sites in the R domain

Wilkinson, Daniel J.; Strong, Theresa V.; Mansoura, Monique K.; Wood, Deborah L.; Smith, Stephen S.; Collins, Francis S.; Dawson, David C.

doi:10.1152/ajplung.1997.273.1.l127

Cited by 83 publications

(111 citation statements)

References 15 publications

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“…Fifteen sites must be eliminated to create CFTR channels that are completely PKA-insensitive (Seibert et al 1999;Hegedus et al 2009). Two PKA sites (S737 and S768) are argued to be inhibitory on the basis of the observation that their disruption increases channel activity (Wilkinson et al 1997;Csanády et al 2005). These sites also appear to be phosphorylated by AMP kinase which inhibits CFTR activity possibly under hypoxic conditions (King et al 2009).…”

Section: Cftr Regulation By Pka Phosphorylationmentioning

confidence: 99%

The CFTR Ion Channel: Gating, Regulation, and Anion Permeation

Hwang

Kirk

2013

Cold Spring Harbor Perspectives in Medicine

105

110

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Section: Cftr Regulation By Pka Phosphorylationmentioning

confidence: 99%

The CFTR Ion Channel: Gating, Regulation, and Anion Permeation

Hwang

Kirk

2013

Cold Spring Harbor Perspectives in Medicine

105

110

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“…The R region may be a similar rheostat, except that primarily its nonphosphorylated state binds. CFTR function is regulated by phosphorylation-dependent modulation of the structural properties of a large number of potential interacting segments, a mechanism that allows a graded CFTR response to PKA binding and phosphorylation 8,10,11 . Moderate channel activity is possible with low levels of phosphorylation, but additional phosphorylation increases CFTR activity 8 .…”

Section: Two Predominant Mechanismsmentioning

confidence: 99%

“…Moderate channel activity is possible with low levels of phosphorylation, but additional phosphorylation increases CFTR activity 8 . Phosphorylation of various sites in the R region has generally additive results, with no single phosphorylation site required for channel activity 8,9 and various impacts on channel activity from mutations at different sites 10,11 .…”

Section: Two Predominant Mechanismsmentioning

confidence: 99%

“…Missense Ser→Ala mutations in PKA consensus motifs, introduced singly or in combination, demonstrate various relative contributions of these positions to channel activity 10,11 . Whereas most phosphorylation sites stimulate channel activity, Ser737 and Ser768 are inhibitory sites.…”

mentioning

confidence: 99%

“…Whereas most phosphorylation sites stimulate channel activity, Ser737 and Ser768 are inhibitory sites. Substitutions at these residues result in increased channel conductance 10 , and removal of residues 760-783 or 817-838 produces active channels that open independently of phosphorylation 12,13 . Coexpression of CFTR and CFTR 837-1480 also produces low levels of constitutive Cl -channel activity, which is further stimulated with PKA 14 .…”

mentioning

confidence: 99%

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CFTR regulatory region interacts with NBD1 predominantly via multiple transient helices

Baker

Hudson

Kanelis

et al. 2007

Nat Struct Mol Biol

265

327

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The regulatory (R) region of the cystic fibrosis transmembrane conductance regulator (CFTR) is intrinsically disordered and must be phosphorylated at multiple sites for full CFTR channel activity, with no one specific phosphorylation site required. In addition, nucleotide binding and hydrolysis at the nucleotide-binding domains (NBDs) of CFTR are required for channel gating. We report NMR studies in the absence and presence of NBD1 that provide structural details for the isolated R region and its interaction with NBD1 at residue-level resolution. Several sites in the R region with measured fractional helical propensity mediate interactions with NBD1. Phosphorylation reduces the helicity of many R-region sites and reduces their NBD1 interactions. This evidence for a dynamic complex with NBD1 that transiently engages different sites of the R region suggests a structural explanation for the dependence of CFTR activity on multiple PKA phosphorylation sites.The CFTR chloride channel, the protein mutated in cystic fibrosis, is a member of the ATPbinding cassette (ABC) superfamily of proteins 1 . Like other members of the superfamily, CFTR has two membrane-spanning domains (MSD1 and MSD2) and two nucleotidebinding domains (NBD1 and NBD2). Intracellular regions between the transmembrane segments probably adopt helical structures that extend from the MSDs 2 . Unique to CFTR is the cytoplasmic intrinsically disordered 3,4 R region, of approximately 200 residues, which we refer to as a region rather than as a domain to reflect its lack of a stable, folded globular structure.

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Phenotype-optimized sequence ensembles substantially improve prediction of disease-causing mutation in cystic fibrosis

et al. 2012

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Cystic fibrosis transmembrane conductance regulator (CFTR) mutation is associated with a phenotypic spectrum that includes cystic fibrosis (CF). The disease liability of some common CFTR mutations is known, but rare mutations are seen in too few patients to categorize unequivocally, making genetic diagnosis difficult. Computational methods can predict the impact of mutation, but prediction specificity is often below that required for clinical utility. Here, we present a novel supervised learning approach for predicting CF from CFTR missense mutation. The algorithm begins by constructing custom multiple sequence alignments called phenotype-optimized sequence ensembles (POSEs). POSEs are constructed iteratively, by selecting sequences that optimize predictive performance on a training set of CFTR mutations of known clinical significance. Next, we predict CF disease liability from a different set of CFTR mutations (test-set mutations). This approach achieves improved prediction performance relative to popular methods recently assessed using the same test-set mutations. Of clinical significance, our method achieves 94% prediction specificity. Because databases such as HGMD and locus-specific mutation databases are growing rapidly, methods that automatically tailor their predictions for a specific phenotype may be of immediate utility. If the performance achieved here generalizes to other systems, the approach could be an excellent tool to help establish genetic diagnoses.

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CFTR activation: additive effects of stimulatory and inhibitory phosphorylation sites in the R domain

Cited by 83 publications

References 15 publications

The CFTR Ion Channel: Gating, Regulation, and Anion Permeation

The CFTR Ion Channel: Gating, Regulation, and Anion Permeation

CFTR regulatory region interacts with NBD1 predominantly via multiple transient helices

Phenotype-optimized sequence ensembles substantially improve prediction of disease-causing mutation in cystic fibrosis

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