Localization and synthesis of an insulin-binding region on human insulin receptor

1990 ◽  
Vol 9 (2) ◽  
pp. 229-233 ◽  
Author(s):  
Shigenori Nakamura ◽  
Shigeki Sakata ◽  
M. Zouhair Atassi
Keyword(s):  
Insulin Receptor ◽  
Human Insulin ◽  
Insulin Binding ◽  
Binding Region ◽  
Human Insulin Receptor

A Radioimmunoassay for Human Insulin Receptor Correlation Between Insulin Binding and Receptor Mass

1991 ◽  
Vol 23 (03) ◽  
pp. 117-121 ◽  
Author(s):  
G. Boden ◽  
F. Jadali ◽  
L. Tappy ◽  
Y. Fujita-Yamaguchi
Keyword(s):  
Insulin Receptor ◽  
Human Insulin ◽  
Insulin Binding ◽  
Human Insulin Receptor

scholarly journals Secretion of the extracellular domain of the human insulin receptor from insect cells by use of a baculovirus vector

1989 ◽  
Vol 261 (1) ◽  
pp. 119-126 ◽  
Author(s):  
J Sissom ◽  
L Ellis
Keyword(s):  
Insulin Receptor ◽  
Human Insulin ◽  
Mammalian Cells ◽  
Culture Medium ◽  
Insect Cells ◽  
Transmembrane Domain ◽  
Binding Protein ◽  
Insulin Binding ◽  
Cell System ◽  
Human Insulin Receptor

To explore the utility of the baculovirus/insect-cell system for the expression of a soluble secreted human insulin-receptor (hIR) extracellular ligand-binding domain, we have engineered a recombinant virus encoding an hIR deletion mutant which is truncated eight residues from the beginning of the predicted transmembrane domain (i.e. 921 residues). Within 24 h after infection of Sf9 cells with virus, insulin-binding activity begins to accumulate in the culture medium, and reaches a maximum between 48 and 72 h. The intracellular transit and processing of this secreted receptor, designated ‘AchIR01’, is quite slow. After 24 h in pulse-chase experiments approximately 50% of the metabolically labelled protein is still inside the cell. This protein accumulates as a non-cleaved hIR precursor which is glycosylated, but the carbohydrate is entirely endoglycosidase H (endoH)-sensitive (i.e. high mannose). Approximately one-half of the receptor in the culture medium (i.e. approximately 25% of the total) is in the form of non-cleaved precursor, and about one half of its carbohydrate chains are now endoH-resistant. The remainder of the protein is proteolytically processed hIR (alpha-plus truncated beta-subunits). None of these hIR species exhibit O-linked carbohydrate. Only the processed form of the receptor in the medium binds insulin. This insulin-binding protein is secreted as a dimer (alpha beta)2, and binds insulin with an affinity which is comparable with that of both the wild-type hIR as well as the secreted form of the hIR expressed in mammalian cells. Despite the rather inefficient processing and altered glycosylation of the AchIR01 protein in insect cells, this high-affinity insulin-binding protein accumulates in the medium at levels (mg/litre) of about 100 times that achieved in a mammalian-cell system.

scholarly journals Identification of the cysteine residues involved in the class I disulfide bonds of the human insulin receptor: properties of insulin receptor monomers.

1996 ◽  
Vol 7 (5) ◽  
pp. 679-691 ◽  
Author(s):  
K Lu ◽  
G Guidotti
Keyword(s):  
Insulin Receptor ◽  
Human Insulin ◽  
Disulfide Bonds ◽  
Insulin Binding ◽  
Site Directed Mutagenesis ◽  
Class I ◽  
Cysteine Residues ◽  
Human Insulin Receptor ◽  
Alpha Beta ◽  
Receptor Dimers

The cysteine residues involved in the class I disulfide bonds between the alpha subunits in the (alpha beta)2 dimer of the human insulin receptor have been identified by labeling with N-ethylmaleimide and by site-directed mutagenesis. Both cysteine 524 and cysteine 682 form interchain disulfide bonds; their conversion to serine residues results in the absence of receptor dimers and the presence of alpha beta monomers. The receptor monomers have a slightly lower affinity for insulin than the native receptor dimers. Insulin binding to the receptor monomers promotes their dimerization in the plasma membrane; at nanomolar concentrations of receptor, both unliganded and liganded receptors are monomers. Receptor monomers are stimulated by insulin to autophosphorylate and to phosphorylate exogenous subtrates with the same efficiency as the receptor dimers. The conclusion is that receptor dimerization is not required to activate the tyrosine kinase activity of the insulin receptor.

scholarly journals Insulin-like and insulin-inhibitory effects of monoclonal antibodies for different epitopes on the human insulin receptor

1987 ◽  
Vol 242 (1) ◽  
pp. 123-129 ◽  
Author(s):  
R Taylor ◽  
M A Soos ◽  
A Wells ◽  
M Argyraki ◽  
K Siddle
Keyword(s):  
Monoclonal Antibodies ◽  
Insulin Receptor ◽  
Human Insulin ◽  
Insulin Binding ◽  
Metabolic Effects ◽  
Alpha Subunit ◽  
Inhibitory Effects ◽  
Molar Basis ◽  
Human Insulin Receptor ◽  
Receptor Beta

Monoclonal antibodies previously shown to react with five distinct epitopes on the human insulin receptor were tested for their metabolic effects on isolated human adipocytes. Two antibodies which reacted with receptor alpha-subunit and completely inhibited 125I-insulin binding mimicked the actions of insulin to stimulate lipogenesis from [14C]glucose and to inhibit catecholamine-induced lipolysis. On a molar basis, these antibodies were comparable in potency with insulin itself. Two other antibodies which decreased insulin binding only slightly or not at all also mimicked these metabolic effects of insulin. One of these antibodies reacted with receptor beta-subunit. In contrast, a further antibody which reacted with alpha-subunit and inhibited insulin binding did not affect basal lipogenesis or catecholamine-induced lipolysis, but was able to antagonize the effects of insulin on these processes. The same antibody antagonized the insulin-like effect of another antibody with which it competed in binding to insulin receptor, but not the effect of an antibody which bound independently to the receptor. It is concluded that binding of ligand at or close to the insulin-binding site is neither necessary nor sufficient to trigger insulin-like metabolic effects, which may rather depend on some general property of antibodies, such as their ability to cross-link and aggregate receptor molecules.

scholarly journals Visualization of ligand-induced transmembrane signalling in the full-length human insulin receptor

2017 ◽  
Author(s):  
Theresia Gutmann ◽  
Kelly H. Kim ◽  
Michal Grzybek ◽  
Thomas Walz ◽  
Ünal Coskun
Keyword(s):  
Insulin Receptor ◽  
Human Insulin ◽  
Insulin Binding ◽  
Structural Rearrangement ◽  
Transmembrane Domains ◽  
Full Length ◽  
Transmembrane Signalling ◽  
Inactive Conformation ◽  
Human Insulin Receptor ◽  
Lipid Nanodiscs

ABSTRACTUsing glycosylated full-length human insulin receptor reconstituted into lipid nanodiscs, we show that insulin binding to the dimeric receptor converts its ectodomains from an inverted U-shaped to a T-shaped conformation. This unprecedented structural rearrangement of the ectodomains propagates to the transmembrane domains, which are well separated in the inactive conformation, but come together upon insulin binding, allowing autophosphorylation of the cytoplasmic kinase domains.

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