Linked Life Data

17158866

Source:http://linkedlifedata.com/resource/pubmed/id/17158866

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
11
pubmed:dateCreated
2007-3-12
pubmed:abstractText
PDZ domains are ubiquitous peptide-binding modules that mediate protein-protein interactions in a wide variety of intracellular trafficking and localization processes. These include the pathways that regulate the membrane trafficking and endocytic recycling of the cystic fibrosis transmembrane conductance regulator (CFTR), an epithelial chloride channel mutated in patients with cystic fibrosis. Correspondingly, a number of PDZ proteins have now been identified that directly or indirectly interact with the C terminus of CFTR. One of these is CAL, whose overexpression in heterologous cells directs the lysosomal degradation of WT-CFTR in a dose-dependent fashion and reduces the amount of CFTR found at the cell surface. Here, we show that RNA interference targeting endogenous CAL specifically increases cell-surface expression of the disease-associated DeltaF508-CFTR mutant and thus enhances transepithelial chloride currents in a polarized human patient bronchial epithelial cell line. We have reconstituted the CAL-CFTR interaction in vitro from purified components, demonstrating for the first time that the binding is direct and allowing us to characterize its components biochemically and biophysically. To test the hypothesis that inhibition of the binding site could also reverse CAL-mediated suppression of CFTR, a three-dimensional homology model of the CAL.CFTR complex was constructed and used to generate a CAL mutant whose binding pocket is correctly folded but has lost its ability to bind CFTR. Although produced at the same levels as wild-type protein, the mutant does not affect CFTR expression levels. Taken together, our data establish CAL as a candidate therapeutic target for correction of post-maturational trafficking defects in cystic fibrosis.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
16
pubmed:volume
282
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
8099-109
pubmed:dateRevised
2007-12-3
pubmed:meshHeading
pubmed-meshheading:17158866-Amino Acid Sequence, pubmed-meshheading:17158866-Animals, pubmed-meshheading:17158866-COS Cells, pubmed-meshheading:17158866-Carrier Proteins, pubmed-meshheading:17158866-Cell Membrane, pubmed-meshheading:17158866-Cercopithecus aethiops, pubmed-meshheading:17158866-Cystic Fibrosis Transmembrane Conductance Regulator, pubmed-meshheading:17158866-Epithelial Cells, pubmed-meshheading:17158866-Humans, pubmed-meshheading:17158866-Membrane Proteins, pubmed-meshheading:17158866-Molecular Sequence Data, pubmed-meshheading:17158866-Mutagenesis, pubmed-meshheading:17158866-Mutagenesis, Site-Directed, pubmed-meshheading:17158866-Protein Conformation, pubmed-meshheading:17158866-RNA Interference, pubmed-meshheading:17158866-Sequence Homology, Amino Acid, pubmed-meshheading:17158866-Trans-Activators
pubmed:year
2007
pubmed:articleTitle
Targeting CAL as a negative regulator of DeltaF508-CFTR cell-surface expression: an RNA interference and structure-based mutagenetic approach.
pubmed:affiliation
Department of Biochemistry, Dartmouth Medical School, Hanover, New Hampshire 03755, USA.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't, Research Support, N.I.H., Extramural