Linked Life Data

1910046

Source:http://linkedlifedata.com/resource/pubmed/id/1910046

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
26
pubmed:dateCreated
1991-10-21
pubmed:abstractText
Biologically active colloid-gold complexes were used to compare ligand-induced microaggregation, redistribution, and internalization of insulin receptors on Rat 1 fibroblasts expressing wild type (HIRc) or tyrosine kinase-defective (HIR A/K1018) human insulin receptors. Insulin-like growth factor I (IGF I) and alpha 2-macroglobulin receptors also were compared. On both cell types, all four unoccupied receptor types occurred predominantly as single receptors. Ligand binding caused receptor microaggregation. Microaggregation of wild type or kinase-defective insulin receptors or IGF I receptors was not different. alpha 2-Macroglobulin receptors formed larger microaggregates. Compared to wild type insulin or IGF I receptors, accumulation of kinase-defective insulin receptor microaggregates in endocytic structures was decreased, and the size of microaggregates in coated pits was significantly smaller. As a result, receptor-mediated internalization of gold-insulin by HIR A/K1018 cells was less than 6% of the cell-associated particles compared to approximately 60% of the particles in HIRc cells. On HIR A/K1018 cells, alpha 2-macroglobulin and IGF I were internalized via coated pits demonstrating that those structures were functional. These results suggest that: 1) ATP binding, receptor autophosphorylation, and activation of receptor kinase activity are not required for receptor microaggregation; 2) receptor microaggregation per se is not sufficient to cause ligand-induced receptor-mediated internalization or the biological effects of insulin; and 3) autophosphorylation of the beta-subunit or activation of the receptor kinase activity is required for the insulin-induced concentration of occupied receptors in coated pits.
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
15
pubmed:volume
266
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
17522-30
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed:year
1991
pubmed:articleTitle
Tyrosine kinase-defective insulin receptors undergo insulin-induced microaggregation but do not concentrate in coated pits.
pubmed:affiliation
Department of Pathology and Laboratory Medicine, University of Pennsylvania School of Medicine, Philadelphia 19104.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't