Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
18
pubmed:dateCreated
1999-6-3
pubmed:abstractText
The function of the human cystic fibrosis transmembrane conductance regulator (CFTR) protein as a chloride channel or transport regulator involves cellular ATP binding and cleavage. Here we describe that human CFTR expressed in insect (Sf9) cell membranes shows specific, Mg2+-dependent nucleotide occlusion, detected by covalent labeling with 8-azido-[alpha-32P]ATP. Nucleotide occlusion in CFTR requires incubation at 37 degrees C, and the occluded nucleotide can not be removed by repeated washings of the membranes with cold MgATP-containing medium. By using limited tryptic digestion of the labeled CFTR protein we found that the adenine nucleotide occlusion preferentially occurred in the N-terminal nucleotide binding domain (NBD). Addition of the ATPase inhibitor vanadate, which stabilizes an open state of the CFTR chloride channel, produced an increased nucleotide occlusion and resulted in the labeling of both the N-terminal and C-terminal NBDs. Protein modification with N-ethylmaleimide prevented both vanadate-dependent and -independent nucleotide occlusion in CFTR. The pattern of nucleotide occlusion indicates significant differences in the ATP hydrolyzing activities of the two NBDs, which may explain their different roles in the CFTR channel regulation.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
30
pubmed:volume
274
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
12209-12
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1999
pubmed:articleTitle
Nucleotide occlusion in the human cystic fibrosis transmembrane conductance regulator. Different patterns in the two nucleotide binding domains.
pubmed:affiliation
National Institute of Haematology and Immunology, Membrane Research Group of the Hungarian Academy of Sciences, Hungarian Academy of Sciences, H-1113 Budapest, Hungary.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't