Linked Life Data

3498714

Source:http://linkedlifedata.com/resource/pubmed/id/3498714

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
27
pubmed:dateCreated
1987-11-2
pubmed:abstractText
The transferrin receptor cycles rapidly between cell surface and endosomal membrane compartments. Treatment of cultured cells with epidermal growth factor (EGF) or insulin-like growth factor I (IGF-I) at 37 degrees C causes a rapid redistribution of transferrin receptors from an intracellular compartment to the cell surface. The effects of EGF and IGF-I on the kinetics of the cycling of the transferrin receptor in A431 human epidermoid carcinoma cells were compared. The primary site of EGF action was found to be an increase in the rate of transferrin receptor exocytosis. The exocytotic rate constant was measured to be 0.11 min-1 in control cells and 0.33 min-1 in EGF-treated cells. In contrast, IGF-I was found to increase the cell surface expression of transferrin receptors by causing a small increase in the rate of exocytosis (from 0.11 to 0.17 min-1) and a decrease in the rate of endocytosis (from 0.33 to 0.24 min-1). It is concluded that the mechanisms for EGF and IGF-I action to increase the cell surface expression of the transferrin receptor are distinct. A kinetic model of the cycling of the transferrin receptor based on experimentally determined rate constants is presented. The model predicts that a consequence of IGF-I action on transferrin receptor cycling is to decrease the apparent Km for the uptake of diferric transferrin by cells. This prediction is confirmed by direct measurement of the accumulation of 59Fe-labeled diferric transferrin by A431 cells. These data demonstrate that the accumulation of iron by cultured cells is a complex function of the rate of cycling of the transferrin receptor and that this process is under acute regulation by growth factors.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
25
pubmed:volume
262
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
13126-34
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1987
pubmed:articleTitle
Insulin-like growth factor I and epidermal growth factor regulate the expression of transferrin receptors at the cell surface by distinct mechanisms.
pubmed:affiliation
Department of Biochemistry, University of Massachusetts Medical School, Worcester 01605.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.