Linked Life Data

3078838

Source:http://linkedlifedata.com/resource/pubmed/id/3078838

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1990-6-7
pubmed:abstractText
The insulin receptor is an integral transmembrane glycoprotein comprised of two alpha-(approximately 135 kDa) and two beta-(approximately 95 kDa) subunits, which is synthesized as a single polypeptide chain precursor (alpha beta). The primary sequence of the human insulin receptor (hIR) protein, deduced from the nucleotide sequence of cloned human placental mRNAs, predicts two large domains (929 and 403 residues) on either side of a single membrane spanning domain (23 residues); each of these major domains has a distinct function (insulin binding and protein/tyrosine kinase activity, respectively). To experimentally test this deduced topology, and to explore the potential for independent domain function by the hIR extracellular domain, we have constructed an expression plasmid encoding an hIR deletion mutant which is truncated 8 residues from the beginning of the predicted transmembrane domain (i.e., 921 residues). This domain of the hIR is in fact processed into alpha- and truncated beta-subunits and secreted with high efficiency from transfected CHO cell lines which express this mutant hIR, and the protein accumulates as an (alpha beta)2 dimer in the medium. This molecule is recognized by a battery of 13 monoclonal antibodies to epitopes on the IR extracellular domain, four of which block insulin binding and two of which require the native conformation of the IR for recognition. Further, this domain binds insulin with an apparent dissociation constant comparable to that of the wild-type hIR. However, the secreted dimer displays a linear Scatchard plot, while that of the wild-type membrane-associated hIR is curvilinear.(ABSTRACT TRUNCATED AT 250 WORDS)
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0952-3499
pubmed:author
pubmed:issnType
Print
pubmed:volume
1
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
25-31
pubmed:dateRevised
2011-11-17
pubmed:meshHeading
pubmed:year
1988
pubmed:articleTitle
Truncation of the ectodomain of the human insulin receptor results in secretion of a soluble insulin binding protein from transfected CHO cells.
pubmed:affiliation
Howard Hughes Medical Institute, Dallas, TX.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't