Kinetic Evidence for the Sequential Association of Insulin Binding Sites 1 and 2 to the Insulin Receptor and the Influence of Receptor Isoform,

Biochemistry ◽  
2010 ◽  
Vol 49 (29) ◽  
pp. 6234-6246 ◽  
Author(s):  
Karina Sinding Thorsøe ◽  
Morten Schlein ◽  
Dorte Bjerre Steensgaard ◽  
Jakob Brandt ◽  
Gerd Schluckebier ◽  
...  
Keyword(s):  
Insulin Receptor ◽  
Binding Sites ◽  
Insulin Binding

scholarly journals Cryo-EM structure of the complete and ligand-saturated insulin receptor ectodomain

2019 ◽  
Author(s):  
Theresia Gutmann ◽  
Ingmar Schäfer ◽  
Chetan Poojari ◽  
Beate Brankatschk ◽  
Ilpo Vattulainen ◽  
...  
Keyword(s):  
Insulin Receptor ◽  
Binding Sites ◽  
Structural Model ◽  
Receptor Site ◽  
Insulin Binding ◽  
Proximal Region ◽  
Dynamics Simulation ◽  
Structural Basis ◽  
Structure Based Drug Design ◽  
Receptor Interactions

AbstractGlucose homeostasis and growth essentially depend on the peptide hormone insulin engaging its receptor. Despite biochemical and structural advances, a fundamental contradiction has persisted in the current understanding of insulin ligand–receptor interactions. While biochemistry predicts two distinct insulin binding sites, 1 and 2, recent structural analyses have only resolved site 1. Using a combined approach of cryo-EM and atomistic molecular dynamics simulation, we determined the structure of the entire dimeric insulin receptor ectodomain saturated with four insulin molecules. Complementing the previously described insulin–site 1 interaction, we present the first view of insulin bound to the discrete insulin receptor site 2. Insulin binding stabilizes the receptor ectodomain in a T-shaped conformation wherein the membrane-proximal domains converge and contact each other. These findings expand the current models of insulin binding to its receptor and of its regulation. In summary, we provide the structural basis enabling a comprehensive description of ligand–receptor interactions that ultimately will inform new approaches to structure-based drug design.In briefA cryo-EM structure of the complete insulin receptor ectodomain saturated with four insulin ligands is reported. The structural model of the insulin–insulin receptor complex adopts a T-shaped conformation, reveals two additional insulin-binding sites potentially involved in the initial interaction of insulin with its receptor, and resolves the membrane proximal region.

scholarly journals Insulin-like growth factor binding to the atypical insulin receptors of a human lymphoid-derived cell line (IM-9)

1990 ◽  
Vol 266 (3) ◽  
pp. 737-742 ◽  
Author(s):  
H A Jonas ◽  
A J Cox
Keyword(s):  
Growth Factor ◽  
Affinity Chromatography ◽  
Insulin Receptor ◽  
Binding Sites ◽  
Insulin Binding ◽  
Type I ◽  
Insulin Like Growth Factor ◽  
Igf Receptors ◽  
Type I Igf Receptor ◽  
Igf I

The cells of the IM-9 human lymphocyte-derived line contain a sub-population of insulin-binding sites whose immunological and hormone-binding characteristics closely resemble those of the atypical insulin-binding sites of human placenta. These binding sites, which have moderately high affinity for multiplication-stimulating activity [MSA, the rat homologue of insulin-like growth factor (IGF) II] and IGF-I, are identified on IM-9 cells by 125I-MSA binding. They account for approximately 30% of the total insulin-receptor population, and do not react with a monoclonal antibody to the type I IGF receptor (alpha IR-3). The relative concentrations of unlabelled insulin, MSA and IGF-I required to displace 50% of 125I-MSA from these binding sites (1:4.7:29 respectively) are maintained for cells, particulate membranes, Triton-solubilized membranes precipitated either by poly(ethylene glycol) or a polyclonal antibody (B-10) to the insulin receptor, and receptors purified by insulin affinity chromatography. Because the atypical insulin/MSA-binding sites outnumber the type I IGF receptors in IM-9 cells by approximately 10-fold, they also compete with the latter receptors for 125I-IGF-I binding. Thus 125I-IGF-I binding to IM-9 cells is inhibited by moderately low concentrations of insulin (relative potency ratios for insulin compared with IGF-I are approx. 1/14 to 1/4) and is partially displaced (65-80%) by alpha IR-3. When type I IGF receptors are blocked by alpha IR-3 or removed by B-10 immunoprecipitation or insulin affinity chromatography, the hormone-displacement patterns for 125I-IGF-I binding resemble those of the atypical insulin/MSA-binding sites.

scholarly journals Cryo-EM structure of the complete and ligand-saturated insulin receptor ectodomain

2019 ◽  
Vol 219 (1) ◽  
Author(s):  
Theresia Gutmann ◽  
Ingmar B. Schäfer ◽  
Chetan Poojari ◽  
Beate Brankatschk ◽  
Ilpo Vattulainen ◽  
...  
Keyword(s):  
Insulin Receptor ◽  
Binding Sites ◽  
Receptor Site ◽  
Insulin Binding ◽  
Dynamics Simulation ◽  
Structural Basis ◽  
Combined Approach ◽  
Comprehensive Description ◽  
Structure Based Drug Design ◽  
Receptor Interactions

Glucose homeostasis and growth essentially depend on the hormone insulin engaging its receptor. Despite biochemical and structural advances, a fundamental contradiction has persisted in the current understanding of insulin ligand–receptor interactions. While biochemistry predicts two distinct insulin binding sites, 1 and 2, recent structural analyses have resolved only site 1. Using a combined approach of cryo-EM and atomistic molecular dynamics simulation, we present the structure of the entire dimeric insulin receptor ectodomain saturated with four insulin molecules. Complementing the previously described insulin–site 1 interaction, we present the first view of insulin bound to the discrete insulin receptor site 2. Insulin binding stabilizes the receptor ectodomain in a T-shaped conformation wherein the membrane-proximal domains converge and contact each other. These findings expand the current models of insulin binding to its receptor and of its regulation. In summary, we provide the structural basis for a comprehensive description of ligand–receptor interactions that ultimately will inform new approaches to structure-based drug design.

scholarly journals Increased levels of insulin and insulin-like growth factor-1 hybrid receptors and decreased glycosylation of the insulin receptor alpha- and beta-subunits in scrapie-infected neuroblastoma N2a cells

2004 ◽  
Vol 380 (2) ◽  
pp. 571-579 ◽  
Author(s):  
Daniel NIELSEN ◽  
Hanna GYLLBERG ◽  
Pernilla ÖSTLUND ◽  
Tomas BERGMAN ◽  
Katarina BEDECS
Keyword(s):  
Growth Factor ◽  
Insulin Receptor ◽  
Binding Sites ◽  
Cellular Localization ◽  
Fold Increase ◽  
Insulin Binding ◽  
Proteolytic Processing ◽  
Insulin Like Growth Factor ◽  
N2a Cells ◽  
Α And Β Subunits

We have previously shown that ScN2a cells (scrapie-infected neuroblastoma N2a cells) express 2-fold- and 4-fold-increased levels of IR (insulin receptor) and IGF-1R (insulin-like growth factor-1 receptor) respectively. In addition, the IR α- and β-subunits are aberrantly processed, with apparent molecular masses of 128 and 85 kDa respectively, as compared with 136 and 95 kDa in uninfected N2a cells. Despite the 2-fold increase in IR protein, the number of 125I-insulin-binding sites was slightly decreased in ScN2a cells [Östlund, Lindegren, Pettersson and Bedecs (2001) Brain Res. 97, 161–170]. In order to determine the cellular localization of IR in ScN2a cells, surface biotinylation was performed, showing a correct IR trafficking and localization to the cell surface. The present study shows for the first time that neuroblastoma N2a cells express significant levels of IR–IGF-1R hybrid receptors, and in ScN2a cells the number of hybrid receptors was 2-fold higher than that found in N2a cells, potentially explaining the apparent loss of insulin-binding sites due to a lower affinity for insulin compared with the homotypic IR. Furthermore, the decreased molecular mass of IR subunits in ScN2a cells is not caused by altered phosphorylation or proteolytic processing, but rather by altered glycosylation. Enzymic deglycosylation of immunoprecipitated IR from N2a and ScN2a cells with endoglycosidase H, peptide N-glycosidase F and neuraminidase all resulted in subunits with increased electrophoretic mobility; however, the 8–10 kDa shift remained. Combined enzymic or chemical deglycosylation using anhydrous trifluoromethane sulphonic acid treatment ultimately showed that the IR α- and β-subunits from ScN2a cells are aberrantly glycosylated. The increased formation of IR–IGF-1R hybrids in ScN2a cells may be part of a neuroprotective response to prion infection. The degree and functional significance of aberrantly glycosylated proteins in ScN2a cells remain to be determined.

Glucagon-like peptide-1 improves insulin and proinsulin binding on RINm5F cells and human monocytes

2000 ◽  
Vol 279 (1) ◽  
pp. E88-E94 ◽  
Author(s):  
Martin Ebinger ◽  
Daniela R. Jehle ◽  
Rolf D. Fussgaenger ◽  
Hans C. Fehmann ◽  
Peter M. Jehle
Keyword(s):  
Insulin Receptor ◽  
Receptor Binding ◽  
Binding Sites ◽  
High Capacity ◽  
Insulin Binding ◽  
Rinm5f Cells ◽  
Insulin Receptor Binding ◽  
Glucagon Like Peptide 1

Glucagon-like peptide-1-(7—36) amide (GLP-1) is a potent incretin hormone secreted from distal gut. It stimulates basal and glucose-induced insulin secretion and proinsulin gene expression. The present study tested the hypothesis that GLP-1 may modulate insulin receptor binding. RINm5F rat insulinoma cells were incubated with GLP-1 (0.01–100 nM) for different periods (1 min-24 h). Insulin receptor binding was assessed by competitive ligand binding studies. In addition, we investigated the effect of GLP-1 on insulin receptor binding on monocytes isolated from type 1 and type 2 diabetes patients and healthy volunteers. In RINm5F cells, GLP-1 increased the capacity and affinity of insulin binding in a time- and concentration-dependent manner. The GLP-1 receptor agonist exendin-4 showed similar effects, whereas the receptor antagonist exendin-(9—39) amide inhibited the GLP-1-induced increase in insulin receptor binding. The GLP-1 effect was potentiated by the adenylyl cyclase activator forskolin and the stable cAMP analog Sp-5,6-dichloro-1- β-d-ribofuranosyl-benzimidazole-3′,5′-monophosphorothioate but was antagonized by the intracellular Ca2+ chelator 1,2-bis(0-aminophenoxy)ethane- N,N,N′,N′-tetraacetic acid-AM. Glucagon, gastric inhibitory peptide (GIP), and GIP-(1—30) did not affect insulin binding. In isolated monocytes, 24 h incubation with 100 nM GLP-1 significantly ( P < 0.05) increased the diminished number of high-capacity/low-affinity insulin binding sites per cell in type 1 diabetics (9,000 ± 3,200 vs. 18,500 ± 3,600) and in type 2 diabetics (15,700 ± 2,100 vs. 28,900 ± 1,800) compared with nondiabetic control subjects (25,100 ± 2,700 vs. 26,200 ± 4,200). Based on our previous experiments in IEC-6 cells and IM-9 lymphoblasts indicating that the low-affinity/high-capacity insulin binding sites may be more specific for proinsulin (Jehle, PM, Fussgaenger RD, Angelus NK, Jungwirth RJ, Saile B, and Lutz MP. Am J Physiol Endocrinol Metab276: E262–E268, 1999 and Jehle, PM, Lutz MP, and Fussgaenger RD. Diabetologia 39: 421–432, 1996), we further investigated the effect of GLP-1 on proinsulin binding in RINm5F cells and monocytes. In both cell types, GLP-1 induced a significant increase in proinsulin binding. We conclude that, in RINm5F cells and in isolated human monocytes, GLP-1 specifically increases the number of high-capacity insulin binding sites that may be functional proinsulin receptors.

scholarly journals Localization of the insulin receptor binding sites for the SH2 domain proteins p85, Syp, and GAP.

1994 ◽  
Vol 269 (44) ◽  
pp. 27186-27192
Author(s):  
P A Staubs ◽  
D R Reichart ◽  
A R Saltiel ◽  
K L Milarski ◽  
H Maegawa ◽  
...  
Keyword(s):  
Insulin Receptor ◽  
Receptor Binding ◽  
Binding Sites ◽  
Sh2 Domain ◽  
Insulin Receptor Binding
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