Linked Life Data

2436896

Source:http://linkedlifedata.com/resource/pubmed/id/2436896

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
1987-6-1
pubmed:abstractText
We have characterized the interaction of insulin-like growth factor II (IGF-II) with its plasma membrane receptor(s) on cultured rat chondrocytes. Our studies, paralleling those already reported for IGF-I, demonstrate that [125I]IGF-II binds to these receptors with a high degree of affinity and that this process is reversible, specific, and time, temperature, and concentration dependent. At 4 C, unlabeled IGF-II causes half-maximal displacement of the labeled ligand at a concentration of 22 ng/ml, whereas IGF-I is approximately 1/200th as potent, and insulin does not displace [125I]IGF-II even at a concentration of 10 micrograms/ml. Maximum binding to chondrocytes (44% of added radioactivity) occurred after 4-5 h of incubation at 15 C. Compared to [125I]IGF-I binding, this value is 7-fold higher and is consistent with an affinity constant (Ka = 3.8 X 10(8) M-1) approximately 1 order of magnitude greater. Photoaffinity labeling studies disclose that IGF-II binds primarily to the type II IGF receptor, which has an apparent mol wt of 220K when electrophoresed under nonreducing conditions and 270K under reducing conditions. Nanomolar concentrations of IGF-II stimulated the synthesis of DNA and RNA in a dose-related manner, and micromolar concentrations of insulin demonstrated an additive effect with respect to the incorporation of [3H]thymidine into DNA, but not [3H]uridine into RNA. Preincubation of rat chondrocytes with increasing concentrations of insulin caused a marked dose-related increase in [125I]IGF-II binding, a phenomenon previously reported in several other cell types. In addition to defining the binding characteristics of IGF-II, we used the lysosomotropic agents chloroquine and ammonium chloride to demonstrate that its ligand-receptor complex, like that of IGF-I, is internalized and degraded partially via the lysosomal pathway.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0013-7227
pubmed:author
pubmed:issnType
Print
pubmed:volume
120
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2108-16
pubmed:dateRevised
2011-11-17
pubmed:meshHeading
pubmed-meshheading:2436896-Affinity Labels, pubmed-meshheading:2436896-Ammonium Chloride, pubmed-meshheading:2436896-Animals, pubmed-meshheading:2436896-Binding, Competitive, pubmed-meshheading:2436896-Cartilage, pubmed-meshheading:2436896-Cell Membrane, pubmed-meshheading:2436896-Cells, Cultured, pubmed-meshheading:2436896-Chloroquine, pubmed-meshheading:2436896-DNA, pubmed-meshheading:2436896-Insulin, pubmed-meshheading:2436896-Insulin-Like Growth Factor II, pubmed-meshheading:2436896-Kinetics, pubmed-meshheading:2436896-Photochemistry, pubmed-meshheading:2436896-RNA, pubmed-meshheading:2436896-Rats, pubmed-meshheading:2436896-Rats, Inbred Strains, pubmed-meshheading:2436896-Receptor, Insulin, pubmed-meshheading:2436896-Receptors, Somatomedin, pubmed-meshheading:2436896-Somatomedins, pubmed-meshheading:2436896-Temperature
pubmed:year
1987
pubmed:articleTitle
Interaction of insulin-like growth factor II with rat chondrocytes: receptor binding, internalization, and degradation.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.