Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
Pt 8
pubmed:dateCreated
2009-4-2
pubmed:abstractText
ClC-4 is closely related to ClC-5, a member of the ClC family of transporters and channels. Unlike ClC-5, for which a role in the regulation of endosomal function was well established, the cellular function of ClC-4 was uncertain. In the present study, we tested for a specific role for ClC-4 in recycling endosomes by comparing transferrin (Tfn) receptor function in primary cell lines generated from ClC-4-null mice and their wild-type siblings. We found that endosomal pH is relatively alkaline and receptor-mediated uptake of Tfn is reduced in ClC-4-null fibroblasts. Surprisingly, this reduction in Tfn uptake occurs, despite a minor increase in the total surface expression of the Tfn receptor in ClC-4-null fibroblasts. As impaired Tfn uptake by ClC-4-null fibroblasts could be rescued to wild-type levels by addition of the iron chelator: desoxiferramine, the primary defect in these cells is related to the failure of iron to dissociate from Tfn, a pH-dependent event in endosomes that precedes the dissociation of Tfn from its receptor at the cell surface. Interestingly, ClC-4 depletion had no effect on epidermal growth factor receptor (EGFR) trafficking to lysosomes for degradation pointing to its specific role in recycling endosomes. These observations provide direct evidence supporting an essential role for ClC-4 in the modulation of Tfn receptor accessibility at the cell surface through its role in endosomal acidification.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0021-9533
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
122
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1229-37
pubmed:dateRevised
2011-11-17
pubmed:meshHeading
pubmed-meshheading:19339555-Animals, pubmed-meshheading:19339555-Cells, Cultured, pubmed-meshheading:19339555-Chloride Channels, pubmed-meshheading:19339555-Endocytosis, pubmed-meshheading:19339555-Endosomes, pubmed-meshheading:19339555-Fibroblasts, pubmed-meshheading:19339555-Hydrogen-Ion Concentration, pubmed-meshheading:19339555-Iron Chelating Agents, pubmed-meshheading:19339555-Mice, pubmed-meshheading:19339555-Mice, Inbred C57BL, pubmed-meshheading:19339555-Mice, Knockout, pubmed-meshheading:19339555-Protein Transport, pubmed-meshheading:19339555-RNA, Messenger, pubmed-meshheading:19339555-Receptor, Epidermal Growth Factor, pubmed-meshheading:19339555-Receptors, Transferrin, pubmed-meshheading:19339555-Time Factors, pubmed-meshheading:19339555-Transfection, pubmed-meshheading:19339555-Transferrin
pubmed:year
2009
pubmed:articleTitle
An essential role for ClC-4 in transferrin receptor function revealed in studies of fibroblasts derived from Clcn4-null mice.
pubmed:affiliation
Programme in Molecular Structure and Function, Hospital for Sick Children, Toronto, Canada.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't