Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
31
pubmed:dateCreated
1999-8-19
pubmed:abstractText
Defective cAMP-stimulated chloride conductance of the plasma membrane of epithelial cell is the hallmark of cystic fibrosis (CF) and results from mutations in the cystic fibrosis transmembrane conductance regulator, CFTR. In the majority of CF patients, mutations in the CFTR lead to its misfolding and premature degradation at the endoplasmic reticulum (ER). Other mutations impair the cAMP-dependent activation or the ion conductance of CFTR chloride channel. In the present work we identify a novel mechanism leading to reduced expression of CFTR at the cell surface, caused by C-terminal truncations. The phenotype of C-terminally truncated CFTR, representing naturally occurring premature termination and frameshift mutations, were examined in transient and stable heterologous expression systems. Whereas the biosynthesis, processing, and macroscopic chloride channel function of truncated CFTRs are essentially normal, the degradation rate of the mature, complex-glycosylated form is 5- to 6-fold faster than the wild type CFTR. These experiments suggest that the C terminus has a central role in maintaining the metabolic stability of the complex-glycosylated CFTR following its exit from the ER and provide a plausible explanation for the severe phenotype of CF patients harboring C-terminal truncations.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
30
pubmed:volume
274
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
21873-7
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed-meshheading:10419506-1-Methyl-3-isobutylxanthine, pubmed-meshheading:10419506-Animals, pubmed-meshheading:10419506-COS Cells, pubmed-meshheading:10419506-Cell Line, pubmed-meshheading:10419506-Cell Membrane, pubmed-meshheading:10419506-Codon, Terminator, pubmed-meshheading:10419506-Cricetinae, pubmed-meshheading:10419506-Cystic Fibrosis, pubmed-meshheading:10419506-Cystic Fibrosis Transmembrane Conductance Regulator, pubmed-meshheading:10419506-DNA Primers, pubmed-meshheading:10419506-Databases, Factual, pubmed-meshheading:10419506-Frameshift Mutation, pubmed-meshheading:10419506-Heterozygote, pubmed-meshheading:10419506-Humans, pubmed-meshheading:10419506-Membrane Potentials, pubmed-meshheading:10419506-Polymerase Chain Reaction, pubmed-meshheading:10419506-Protein Folding, pubmed-meshheading:10419506-Recombinant Proteins, pubmed-meshheading:10419506-Sequence Deletion, pubmed-meshheading:10419506-Transfection
pubmed:year
1999
pubmed:articleTitle
C-terminal truncations destabilize the cystic fibrosis transmembrane conductance regulator without impairing its biogenesis. A novel class of mutation.
pubmed:affiliation
Program in Cell Biology and Lung Gene Therapy, Hospital for Sick Children Research Institute, 555 University Avenue, Toronto, Ontario M5G 1X8, Canada.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't