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Jacobs S, Cuatrecasas P. Insulin receptors and insulin receptor antibodies: structure-function relationships. CIBA FOUNDATION SYMPOSIUM 2008:82-90. [PMID: 6923809 DOI: 10.1002/9780470720721.ch6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
The insulin receptor has been purified by affinity chromatography and studied by affinity-labelling techniques. It appears to be a disulphide-linked heterotetramer, (alpha beta)2, composed of two copies of a 135,000 Mr subunit (alpha), and two copies of a 90,000 Mr subunit (beta). Beta is readily proteolysed to generate a 45,000 Mr fragment (beta 1). Alpha, beta and beta 1 all contain sialic acid and are, therefore, probably all exposed on the external surface of the membrane. Although alpha is predominantly labelled in affinity-labelling studies, beta and beta 1 can also be labelled. Therefore, alpha, beta and beta 1 are all in proximity to the insulin-binding site and may contain part of the binding site. Antibodies have been prepared against the intact, purified receptor and against the isolated alpha subunit. Both antibodies directly interact with the insulin receptor as indicated by their ability to immunoprecipitate the receptor. Neither antibody, however, directly competes with insulin binding. Therefore, they are probably directed against regions of the receptor distinct from the insulin-binding site. In spite of this, these antibodies have a wide range of insulin-like activities.
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2
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Kahn CR, Kasuga M, King GL, Grunfeld C. Autoantibodies to insulin receptors in man: immunological determinants and mechanism of action. CIBA FOUNDATION SYMPOSIUM 2008:91-113. [PMID: 6183063 DOI: 10.1002/9780470720721.ch7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The insulin receptor is a membrane glycoprotein of high Mr which binds insulin with high affinity and specificity and transmits some intracellular signal(s) that initiate(s) insulin action. Antibodies to the receptor have been identified in patients with a syndrome characterized by severe resistance to endogenous and exogenous insulin, varying degrees of glucose intolerance, and the skin lesion acanthosis nigricans. The syndrome is most common in non-Caucasian, middle-aged women, but occurs in patients of all races, both sexes, and spanning the ages of 12-62. Most patients have evidence of other autoimmune disease with increased erythrocyte sedimentation rate and gamma globulins, anti-DNA and anti-nuclear antibodies, leucopenia, and other signs and symptoms of autoimmune disease. Antibodies to the insulin receptor are detected by their ability to inhibit 125I-insulin binding or to immunoprecipitate solubilized insulin receptors. In vitro these antibodies acutely mimic most of insulin's metabolic effects. This insulin-like activity depends on antibody bivalence; monovalent Fab fragments block insulin binding and action but lack intrinsic activity. With prolonged exposure of cells to anti-receptor antibody the insulin-like effect is lost and a state of insulin resistance ensues. This is due to both a blockage of insulin binding and a form of post-receptor desensitization. The possible causation of anti-receptor antibodies in this condition is discussed.
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3
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Cousin JL, del Vesco P, Samson M, Brandenburg D, Fehlmann M. Binding of antigen to Ia molecules on intact antigen presenting cells demonstrated by photoaffinity labeling. Mol Immunol 1989; 26:293-9. [PMID: 2649792 DOI: 10.1016/0161-5890(89)90083-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
We used a photoaffinity labeling technique to investigate whether a molecular interaction occurs between antigen and Ia molecules on antigen presenting cells (APC) in the absence of T lymphocytes. M.12.4.1 B lymphoma cells (Iad), which are able to present bovine insulin to Iad lymph node primed T cells, were given radioiodinated bovine insulin derivatized with the photoreactive group (2-nitro-4-azidophenylacetyl) at Lys 29 of the B chain of the insulin molecule. Processing of insulin was allowed by incubating the APC with antigen for increasing periods of time at 37 degrees C or 4 degrees C. The covalent coupling of the processed photoreactive antigen to any neighboring cellular protein was thereafter induced by u.v. irradiation. Immunoprecipitation of membrane proteins by monoclonal antibodies showed that under these conditions, the alpha and beta subunits of the Ia molecules were selectively photolabeled. Labeling was time- and temp-dependent as was the internalization of insulin. The apparent mol. wts of the antigen-Ia molecule complexes were not significantly different from that of native Ia molecules radioiodinated by surface labeling, indicating that only a small fragment of the antigen was covalently coupled to Ia molecules. Similar experiments performed with human B lymphoma cells (526 cells) gave similar results. These observations therefore indicate: (1) that Ia molecules expressed by intact APC are able to bind antigens in the absence of T lymphocyte antigen receptor; and (2) that this association, at least for insulin, requires uptake and a proteolytic fragmentation of the antigen by the APC.
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Affiliation(s)
- J L Cousin
- INSERM U210, Faculté de Médecine (Pasteur), Nice, France
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4
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Abstract
Promising progress in understanding the molecular basis of insulin action has been achieved by demonstrating that the insulin receptor is an insulin-sensitive tyrosine kinase. Here we discuss the structure of this receptor kinase and compare it with receptors for related growth factors. We review the known modes to regulate the receptor kinase activity, either through its autophosphorylation (on tyrosine residues) or through its phosphorylation by other kinases (on serine and threonine residues). We discuss the role of the receptor kinase activity in hormone signal transduction in light of results indicating a reduced kinase activity in insulin-resistant states. Finally, studies to identify natural substrates for the insulin receptor kinase are presented. The possible physiological role of these phosphorylated substrates in mediating insulin action is evaluated.
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Affiliation(s)
- Y Zick
- Department of Chemical Immunology, Weizmann Institute of Science, Rehovot, Israel
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5
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Mokoena L, Alberts M, Tyobeka E. Effects of gluconeogenic hormones on insulin binding in intact human red blood cells. Biochem Biophys Res Commun 1987; 147:158-67. [PMID: 3307773 DOI: 10.1016/s0006-291x(87)80101-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The effects of gluconeogenic hormones, adrenaline and cortisol, on insulin binding were studied in intact human red blood cells. Insulin binding was significantly decreased when red blood cells were preincubated with 1.0 microgram . ml-1 adrenaline or cortisol respectively. The Scatchard plot suggested that this was due to a decrease in surface receptor concentration. Furthermore, it showed that adrenaline also increased insulin receptor affinity. The negative co-operativity affinity profile demonstrated that adrenaline caused a rise in only the upper limit average affinity, Ki, of the insulin receptor.
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Karasik A, Kahn CR. Antibodies to the insulin receptor as tools in the study of receptor structure and function. Ann N Y Acad Sci 1987; 505:301-12. [PMID: 2446553 DOI: 10.1111/j.1749-6632.1987.tb51298.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- A Karasik
- Joslin Diabetes Center, Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts 02215
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Krämer H, Deger A, Koch R, Rapp R, Hinz M, Weber U. Generation of oligomeric insulin receptor forms by intramolecular sulfhydryl-disulfide exchange. Involvement of masked sulfhydryl groups. BIOLOGICAL CHEMISTRY HOPPE-SEYLER 1987; 368:471-9. [PMID: 3304334 DOI: 10.1515/bchm3.1987.368.1.471] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Insulin receptors from rat liver membranes were labelled with a 125I-labelled photoreactive insulin analogue or by iodination using lactoperoxidase and analysed by sodium dodecyl sulfate polyacrylamide gel electrophoresis. Under nonreducing conditions different receptor forms with Mr 400,000 (alpha 2 beta 2), 360,000 (alpha 2 beta beta'), 330,000 (alpha 2 beta' beta'), 320,000 (alpha 2 beta), 280,000 (alpha 2 beta'), 240,000 (alpha 2), 210,000 (alpha beta), 165,000 (alpha beta') and 115,000 (alpha) were detected. The subunit composition of these receptor forms was determined by two-dimensional sodium dodecyl sulfate polyacrylamide gel electrophoresis in the absence and presence of dithioerythritol. During denaturation in sodium dodecyl sulfate in the absence of reductants, the Mr 400,000 receptor form (alpha 2 beta 2) was converted into the Mr 320,000 (alpha 2 beta) and Mr 240,000 (alpha 2) receptor form. This conversion was prevented either by N-ethylmaleimide, oxidants, or low pH. In contrast, alkylation of the receptor with N-ethylmaleimide under non-denaturing conditions did not prevent the appearance of intermediate-sized receptor forms. Furthermore, the inhibition of receptor cleavage by N-ethylmaleimide during denaturation was also observed when the amount of free sulfhydryl groups was reconstituted by the addition of an unlabelled and non-alkylated receptor sample to the alkylated and photoaffinity-labelled receptor. These results suggest, that the generation of different oligomeric receptor forms detected by sodium dodecyl sulfate polyacrylamide gel electrophoresis is due at least in part to the cleavage of one or both beta-subunits from the insulin receptor.(ABSTRACT TRUNCATED AT 250 WORDS)
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Nagao M, Sakamoto C, Matozaki T, Baba S. Disulfide bonds within the alpha-subunit of insulin receptors in rat liver and brain membranes. FEBS Lett 1987; 214:107-10. [PMID: 3569509 DOI: 10.1016/0014-5793(87)80022-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
We have characterized inter- and intrasubunit disulfide bonds of insulin receptors using reductant-treated rat liver and brain membranes. In autoradiograms of 125I-insulin cross-linked to both membranes pretreated with dithiothreitol, the intensity of affinity-labeled bands of the alpha beta-heterodimer and alpha-subunit was increased. Interestingly, labeled 120 and 110 kDa bands considered to be the alpha-subunit in partially reduced liver and brain membranes moved to 130 and 120 kDa bands under further reduced conditions, respectively. Double electrophoresis of each partially reduced band in the presence of reductants clearly demonstrates that the alpha-subunit of insulin receptors contains intrasubunit disulfide bonds.
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9
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Cousin JL, Samson M, Pilch PF, Fehlmann M. Internalization of insulin receptors and HLA antigens in human hepatoma cells. Biochem J 1987; 242:403-10. [PMID: 3036089 PMCID: PMC1147719 DOI: 10.1042/bj2420403] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Human HepG2 hepatoma cells express a high number of insulin receptors. Growing cells exhibit 70% of their insulin receptors on the plasma membrane. Moreover, cell-surface insulin receptors form molecular complexes with class I major histocompatibility antigens, as determined by co-immunoprecipitation of the receptors by anti-class I monoclonal antibodies. On exposure to saturating concentrations of insulin, the hormone is rapidly internalized into a Pronase-resistant compartment. Internalization of insulin is accompanied by a rapid (t1/2 = 2-3 min) redistribution of insulin receptors from the cell surface to an intracellular compartment. On removal of insulin from the medium, functional receptors recycle back to the plasma membrane, where they can bind insulin again. With chronic exposure of HepG2 cells to insulin, the initial redistribution of receptors is followed by a slow (t1/2 = 9 h) down-regulation of the receptors. Finally, notwithstanding their interaction at the cell surface, insulin receptors and class I major histocompatibility antigens are internalized at different rates and with independent regulation.
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Lesniak MA, Hedo JA, Grunberger G, Marcus-Samuels B, Roth J, Gorden P. Receptors for insulin and growth hormone on lymphoid cells. Methods Enzymol 1987; 150:701-23. [PMID: 2828829 DOI: 10.1016/0076-6879(87)50116-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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Juul SM, Neffe J, Evans JL, Jones RH, Sönksen PH, Brandenburg D. Demonstration that the insulin receptor undergoes an early structural modification following insulin binding. BIOCHIMICA ET BIOPHYSICA ACTA 1986; 856:320-4. [PMID: 3513838 DOI: 10.1016/0005-2736(86)90042-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Processing of the insulin receptor by hepatocytes was studied using a 125I-labelled photoreactive insulin derivative which could be covalently attached to the receptor and facilitate the analysis of receptor structure in isolated subcellular fractions by SDS-polyacrylamide gel electrophoresis. Following binding at the cell surface, the label was rapidly internalised and located in a low-density subcellular fraction ('endosomes'). The intact receptor (350 000 molecular weight) and binding (alpha) subunit (135 000), produced by in vitro disulphide reduction of the samples, were found in the plasma membrane fraction but not in endosomes. In endosomes, the label was concentrated in a band at 140 000 (non-reduced) which on reduction generated species of 100 000 and 68 000 predominantly. The insulin receptor therefore undergoes an early structural change during endocytosis. This modification does not involve complete disulphide reduction and may be due to a proteolytic event.
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12
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Juul SM, Jones RH, Evans JL, Neffe J, Sönksen PH, Brandenburg D. Evidence for an early degradative event to the insulin molecule following binding to hepatocyte receptors. BIOCHIMICA ET BIOPHYSICA ACTA 1986; 856:310-9. [PMID: 3513837 DOI: 10.1016/0005-2736(86)90041-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
We have used photoreactive insulin analogues to investigate as related processes, early structural modification of the receptor-bound insulin molecule and internalisation of the insulin-receptor complex. In isolated rat hepatocytes an initial modification of bound insulin leads to the generation of a molecular species unchanged in molecular weight but with reduced receptor and antibody binding affinities and altered electrophoretic mobility. Using photoreactive insulin analogues and density gradient cell fractionation the insulin receptor complex has been shown to undergo internalisation from the plasma membrane to a low density vesicular fraction, the endosome. No labelled material was found in lysosomal fractions after up to 10 min incubation at 37 degrees C. The degree of labelling of the endosome fraction depended on the position of the photoreactive group within the insulin molecule. The data suggest that before or during endocytosis, a small peptide is proteolytically cleaved from the C terminus of the insulin B chain.
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Soos MA, Siddle K, Baron MD, Heward JM, Luzio JP, Bellatin J, Lennox ES. Monoclonal antibodies reacting with multiple epitopes on the human insulin receptor. Biochem J 1986; 235:199-208. [PMID: 2427071 PMCID: PMC1146668 DOI: 10.1042/bj2350199] [Citation(s) in RCA: 169] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Monoclonal antibodies for the human insulin receptor were produced following immunization of mice with IM-9 lymphocytes and/or purified placental receptor. Four separate fusions yielded 28 antibodies, all of which reacted with receptor from human placenta, liver and IM-9 cells. Some antibodies cross-reacted to varying degrees with receptor from rabbit, cow, pig and sheep, but none reacted with rat receptor. At least 10 distinct epitopes were recognized as indicated by species specificity and binding competition experiments. All of these epitopes appeared to be on extracellular domains of the receptor as shown by binding of antibodies to intact cells. In some cases the epitopes were further localized to alpha or beta subunits by immunoblotting. Several antibodies inhibited binding of 125I-insulin to the receptor, some had no effect on binding, and others enhanced the binding of 125I-insulin. It is concluded that these antibodies will be valuable probes of receptor structure and function.
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Schüttler A, Diaconescu C, Saunders DJ, Brandenburg D. Time-dependence of biological activity induced by covalent insulin-receptor complexes in rat adipocytes. Biochem J 1985; 232:49-53. [PMID: 3910030 PMCID: PMC1152837 DOI: 10.1042/bj2320049] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Lipogenesis in isolated adipocyte preparations is stimulated when photosensitive insulin derivatives are attached covalently to specific receptors. This response was compared quantitatively with that to reversibly associated insulin, and it was shown that both covalent and reversible insulin-receptor complexes behave very similarly. The extent of stimulation of lipogenesis was studied as a function of time. Cells were incubated in buffer for various times before addition to vials containing 0 (basal) or 10 ng of monocomponent insulin/ml (maximal) and [U-3H]glucose. After 60 min, the toluene-soluble [3H]lipids were measured. The maximal stimulation induced by reversibly bound insulin was virtually constant over a period of 4 h. In contrast, adipocytes to which N alpha B2-(2-nitro-4-azidophenylacetyl)-des-PheB1-insulin had been covalently attached at the start of the experiment showed a loss of stimulation with time when incubated at 37 degrees C. This loss was decreased in the presence of lysosomotropic agents such as chloroquine at concentrations (approx. 200 microM) that had very little or no effect on the basal and maximal lipogenesis rates. A simple method was used to transform the measured rate of loss of stimulation into a rate of loss of effective units. A half-time of 80 min was calculated for the effective covalent insulin-receptor units in adipocytes at 37 degrees C at pH 7.4. This is very close to values reported by others for the internalization of covalent complexes in these cells, suggesting that this may be the causative event for the deactivation of the insulin-receptor unit. The inhibitory effect of chloroquine on the deactivation may indicate that the insulin-receptor complex can function even after internalization.
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Fehlmann M, Chvatchko Y, Brandenburg D, Van Obberghen E, Brossette N. The subunit structure of the insulin receptor and molecular interactions with major histocompatibility complex antigens. Biochimie 1985; 67:1155-9. [PMID: 2416352 DOI: 10.1016/s0300-9084(85)80114-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Insulin receptors were labeled with 125I-photoreactive insulin (specifically labeling alpha-subunits) and by insulin-stimulated autophosphorylation (specifically labeling beta-subunits). The results show that the insulin receptor exists under different free and disulfide-linked combinations of alpha and beta subunits. Moreover, the insulin receptor is closely associated to class I antigens of the major histocompatibility complex to form a high molecular weight multi-molecular membrane complex.
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Peyron JF, Samson M, Van Obberghen E, Brandenburg D, Fehlmann M. Appearance of a functional insulin receptor during rabbit embryogenesis. Diabetologia 1985; 28:369-72. [PMID: 3899821 DOI: 10.1007/bf00283146] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The domain structure of the insulin receptor was investigated in liver and brown adipose tissue of developing rabbits. The structure of the binding domain (alpha-subunit) was analysed after covalent labelling with a 125I photo-reactive insulin analogue. The structure of the tyrosine kinase domain (beta-subunit) and the transmission of the hormonal signal from the alpha-to the beta-subunit were analysed by stimulating with insulin the autophosphorylation of the beta-subunit. Finally, the immunoreactivity of the receptor in developing tissues was assessed with anti-receptor antibodies. The results show that a functional insulin receptor can be detected at the early stages of fetal development in both tissues and is conserved throughout ontogenesis to adulthood.
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18
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Human insulin receptor and its relationship to the tyrosine kinase family of oncogenes. Nature 1985; 313:756-61. [PMID: 2983222 DOI: 10.1038/313756a0] [Citation(s) in RCA: 1613] [Impact Index Per Article: 41.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
We have deduced the entire 1,370-amino-acid sequence of the human insulin receptor precursor from a single complementary DNA clone. The precursor starts with a 27-amino-acid signal sequence, followed by the receptor alpha-subunit, a precursor processing enzyme cleavage site, then the beta-subunit containing a single 23-amino-acid transmembrane sequence. There are sequence homologies to human epidermal growth factor receptor and the members of the src family of oncogene products.
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Heidenreich KA, Yip CC, Frank BH, Olefsky JM. The preparation and characterization of mono-iodinated photoreactive analogs of insulin. Biochem Biophys Res Commun 1985; 126:1138-45. [PMID: 3884003 DOI: 10.1016/0006-291x(85)90304-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Photoreactive derivatives of insulin (B29-(p-azidobenzoyl-insulin) iodinated primarily in either the B26 or A14 tyrosine of insulin were prepared by lactoperoxidase catalyzed iodination followed by separation on reverse-phase high-performance liquid chromatography. The binding affinities and photoaffinity labeling characteristics of these derivatives were studied in isolated rat adipocytes. Under nonreducing conditions, three forms of the insulin receptor were labeled equally by the B26-derivative, the A14-derivative, and the mixture of the iodinated derivatives. When dithiothreitol was used to reduce the radiolabeled receptors, the radioactivity associated with the binding subunit was much less than that in the intact receptor and the magnitude of the decrease was proportional to the amount of iodine in the A chain of the photoderivatives. Use of the photoreactive derivative iodinated primarily in the B26 position resulted in greater labeling of insulin receptor subunits since most of the radioactivity (80%) remained associated with the receptor upon reduction.
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Abstract
The insulin receptor from rat skeletal muscle was characterized. Treatment of muscle membranes with the photoactive insulin analog, 125I[N-epsilonB29-monoazidobenzoyl]-insulin revealed a single protein band of 135,000 Da, the alpha subunit. Iodination of total membrane protein followed by Triton X-100 solubilization and immunoprecipitation demonstrated the presence of a protein band of 90,000 Da, the beta subunit, together with a protein band of 190,000 Da, which may be the receptor precursor. In partially purified receptor preparations, the beta subunit exhibited dose-dependent, insulin-stimulated phosphorylation with incorporation of phosphate solely into tyrosine residues, which was also observed in the 190,000-Da receptor precursor. Purified plasma membranes contained a large amount of insulin-degrading activity which had to be inactivated prior to performing insulin-binding studies. If degradation of insulin was not prevented, apparent enhanced binding in the presence of unlabeled insulin was observed.
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Horuk R, Olefsky JM. Post binding events in insulin action. DIABETES/METABOLISM REVIEWS 1985; 1:59-97. [PMID: 3915252 DOI: 10.1002/dmr.5610010105] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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Kahn CR, Crettaz M. Insulin receptors and the molecular mechanism of insulin action. DIABETES/METABOLISM REVIEWS 1985; 1:5-32. [PMID: 3013542 DOI: 10.1002/dmr.5610010103] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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Jones RH, Juul SM. The insulin receptor--its function and its fate (2). Diabet Med 1984; 1:257-62. [PMID: 6242813 DOI: 10.1111/j.1464-5491.1984.tb01969.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Affiliation(s)
- R H Jones
- Department of Medicine, St Thomas' Hospital Medical School, London, U.K
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Crettaz M, Jialal I, Kasuga M, Kahn CR. Insulin receptor regulation and desensitization in rat hepatoma cells. The loss of the oligomeric forms of the receptor correlates with the change in receptor affinity. J Biol Chem 1984. [DOI: 10.1016/s0021-9258(18)90896-3] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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26
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Internalization of insulin receptors in the isolated rat adipose cell. Demonstration of the vectorial disposition of receptor subunits. J Biol Chem 1984. [DOI: 10.1016/s0021-9258(18)90625-3] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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Direct comparison of the rates of internalization and degradation of covalent receptor-insulin complexes in 3T3-L1 adipocytes. Internalization of occupied receptors is not the rate-limiting step in receptor-hormone complex degradation. J Biol Chem 1984. [DOI: 10.1016/s0021-9258(17)39704-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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28
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Chvatchko Y, Gazzano H, Van Obberghen E, Fehlmann M. Subunit arrangement of insulin receptors in hepatoma cells. Mol Cell Endocrinol 1984; 36:59-65. [PMID: 6745484 DOI: 10.1016/0303-7207(84)90085-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Insulin receptors from rat hepatoma cells were studied by the three following methods. Firstly, the alpha subunit (Mr 130000) was labelled using a 125I-photoreactive insulin analogue and UV irradiation. Secondly, using phosphorylation of partially purified and immunoprecipitated receptors with [gamma-32P]ATP, the beta subunit (Mr 95000) was labelled. Thirdly, both alpha and beta subunits were labelled by surface iodination catalysed by lactoperoxidase followed by cell solubilization and immunoprecipitation of the receptor with anti-receptor antibodies. The results show that the native insulin receptor exists under different forms: free alpha and beta subunits and the following combinations of disulphide-linked oligomers: alpha beta, alpha 2, alpha 2 beta and alpha 2 beta 2. In addition, it appears that there is at least one insulin binding site per alpha subunit, and that the alpha and beta subunits may be in close physical association in the plasma membrane even when they are not linked by disulphide bonds. In intact cells, only the alpha subunit is sensitive to extracellular proteases that cleave preferentially the region of the alpha subunit bearing the sulphydryl groups responsible for the interchain binding.
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Wright DE, Horuk R, Rodbell M. Photoaffinity labeling of the glucagon receptor with a new glucagon analog. EUROPEAN JOURNAL OF BIOCHEMISTRY 1984; 141:63-7. [PMID: 6327311 DOI: 10.1111/j.1432-1033.1984.tb08157.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The preparation, purification and characterization of N epsilon-4- azidophenylamidinoglucagon are described. This photoreactive peptide was found to be 50% as potent as native glucagon in competing with 125I-labeled glucagon for binding to glucagon receptors on rat liver plasma membranes. Similarly, the analog was 50% as potent as native glucagon in its ability to stimulate adenylate cyclase. The photoreactive glucagon analog was radioiodinated to high specific activity with iodine-125 and was used to label rat liver plasma membrane proteins. Analysis of labeled membrane proteins by sodium dodecyl sulfate/polyacrylamide gel electrophoresis revealed covalent incorporation predominantly into a protein of relative molecular mass, Mr, of 50 000-60 000. Occasionally a protein of Mr 170 000-180 000 was also labeled. Irradiation of membranes in the presence of unlabeled glucagon or GTP selectively inhibited the labeling of the 50 000-60 000-Mr protein(s). As a result of these studies we suggest that the sodium-dodecyl-sulfate-dissociated glucagon receptor is a 50 000-60 000-Mr protein.
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31
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Ronnett GV, Knutson VP, Kohanski RA, Simpson TL, Lane MD. Role of glycosylation in the processing of newly translated insulin proreceptor in 3T3-L1 adipocytes. J Biol Chem 1984. [DOI: 10.1016/s0021-9258(17)43084-5] [Citation(s) in RCA: 109] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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Aiyer RA. Structural characterization of insulin receptors. I. Hydrodynamic properties of receptors from turkey erythrocytes. J Biol Chem 1983. [DOI: 10.1016/s0021-9258(17)43761-6] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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Hedo JA, Kahn CR, Hayashi M, Yamada KM, Kasuga M. Biosynthesis and glycosylation of the insulin receptor. Evidence for a single polypeptide precursor of the two major subunits. J Biol Chem 1983. [DOI: 10.1016/s0021-9258(17)44600-x] [Citation(s) in RCA: 95] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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Pessin JE, Gitomer W, Oka Y, Oppenheimer CL, Czech MP. beta-Adrenergic regulation of insulin and epidermal growth factor receptors in rat adipocytes. J Biol Chem 1983. [DOI: 10.1016/s0021-9258(18)32191-4] [Citation(s) in RCA: 114] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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Im JH, Meezan E, Rackley CE, Kim HD. Isolation and characterization of human erythrocyte insulin receptors. J Biol Chem 1983. [DOI: 10.1016/s0021-9258(18)32531-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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Reed BC. Metabolism of covalent receptor-insulin complexes by 3T3-L1 adipocytes. Synthesis and use of photosensitive insulin analogs to study insulin receptor metabolism in cell culture. J Biol Chem 1983. [DOI: 10.1016/s0021-9258(18)32640-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
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Van Obberghen E, Rossi B, Kowalski A, Gazzano H, Ponzio G. Receptor-mediated phosphorylation of the hepatic insulin receptor: evidence that the Mr 95,000 receptor subunit is its own kinase. Proc Natl Acad Sci U S A 1983; 80:945-9. [PMID: 6341991 PMCID: PMC393504 DOI: 10.1073/pnas.80.4.945] [Citation(s) in RCA: 174] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Insulin stimulates the phosphorylation of its own receptor. In the work reported here, the kinase activity responsible for the insulin-stimulated phosphorylation of the insulin receptor was localized. In a first approach, partially purified insulin receptors derived from normal rat hepatocytes were immunoprecipitated with antibodies specific for the insulin receptor; thereafter, the immunoprecipitates were incubated with [gamma-(32)P]-ATP in the absence or presence of insulin (1 muM). NaDodSO(4)/polyacrylamide gel electrophoretic analysis of the immunoprecipitates under reducing conditions revealed autophosphorylation of the beta subunit (M(r) 95,000) of the insulin receptor; the alpha subunit (M(r) 130,000) was not phosphorylated. Further, insulin specifically increased 3- to 4-fold the labeling of its own receptor beta subunit, indicating that anti-receptor antibodies precipitate a functional and insulin-stimulable protein kinase that appears to be independent of cyclic AMP and calcium. To localize more precisely the insulin receptor-related kinase activity, we searched for an ATP-binding site on solubilized insulin receptors. By using covalent labeling with oxidized [alpha-(32)P]ATP, a labeled polypeptide with precisely the same electrophoretic mobility as that of the beta subunit of the insulin receptor (M(r) 95,000) was specifically immunoprecipitated with anti-receptor antibodies. Further, its appearance was prevented when the immunoprecipitation was preceded by incubation with unlabeled insulin. In conclusion, we have shown that an insulin-stimulated phosphorylation site and an ATP-binding site coexist on the beta subunit of the insulin receptor. The simultaneous presence of these two sites on the same receptor subunit indicates that the insulin receptor acts as its own protein kinase.
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Goren HJ, Elliott C, Dudley RA. Adipocyte insulin-binding species: the size and subunit composition of the larger binding species. J Cell Biochem 1983; 21:161-77. [PMID: 6885935 DOI: 10.1002/jcb.240210207] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Several investigators have reported that there are both large and small insulin-binding proteins in plasma membranes; the larger protein demonstrates nonlinear Scatchard binding, and the smaller protein has linear binding. We now present evidence that the larger insulin-binding species consists of four proteins of different sizes. Rat epididymal adipocyte plasma membranes were prebound with 125I-insulin and then exposed to 1 mM disuccinimidyl suberate for 15 min at 2 degrees C. The membranes were solubilized in 0.1% Triton X-100 and applied to a Sepharose 6B column. Peaks of radioactivity from the column were dialyzed, lyophilized, and analyzed by dodecyl-sulphate gel electrophoresis (5%, 100/l; mono/bisacrylamide). Autoradiograms of the gels were scanned with a densitometer. The Sepharose chromatogram revealed four radioactive peaks: peak 1 at column void volume; peak 2, Kav = 0.27; peak 3, Kav = 0.77; and peak 4, Kav = 1.09. Dodecyl sulphate electrophoresis of fractions in peak 2 demonstrated four bands on autoradiography; peak 1 did not enter the gel and peaks 3 and 4 ran with the dye front. Molecular weight estimates of the four insulin-binding species in peak 2 were 600, 500, 420, and 350 K. On dithiothreitol reduction each insulin-binding species yielded subunits of Mr approximately equal to 135 and 18 K. The three largest binding species demonstrated an additional 45-K dalton protein on dithiothreitol reduction, and the 500-K and 420-K binding species also yielded a 49-K dalton protein. These results suggest that the large insulin-binding protein in rat epididymal adipocytes contains several insulin-binding species, and that these insulin-binding species differ in the number of and the type of subunits they contain. In addition, it may be postulated that the nonlinear Scatchard binding associated with the larger binding protein is a consequence of the heterogeneity of the insulin-binding species in this Sepharose peak.
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Harrison LC. Autoantibodies to hormone receptors. SPRINGER SEMINARS IN IMMUNOPATHOLOGY 1982; 5:447-62. [PMID: 6298962 DOI: 10.1007/bf01857430] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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Petruzzelli LM, Ganguly S, Smith CJ, Cobb MH, Rubin CS, Rosen OM. Insulin activates a tyrosine-specific protein kinase in extracts of 3T3-L1 adipocytes and human placenta. Proc Natl Acad Sci U S A 1982; 79:6792-6. [PMID: 6294652 PMCID: PMC347219 DOI: 10.1073/pnas.79.22.6792] [Citation(s) in RCA: 234] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Insulin activates a tyrosine-specific cAMP-independent protein kinase when added directly to detergent extracts of differentiated 3T3-L1 adipocytes and humal placental membranes. The kinase is also activated by antibody to the insulin receptor and, to a lesser extent, by proinsulin. It catalyzes the phosphorylation of the 92,000-dalton component of the insulin receptor, histone, and casein; in each case, tyrosine is the principal amino acid modified. Under the conditions used to activate the kinase, insulin does not affect the rate of dephosphorylation of the receptor or of histone. The insulin-activated kinase is copurified with the human placental insulin receptor until the final elution from insulin-Sepharose. It remains to be established whether the kinase and the insulin receptor are separate molecules.
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Baron MD, Sönksen PH. Characterization of two insulin-binding components of rat-liver plasma membranes. Biosci Rep 1982; 2:785-93. [PMID: 6756497 DOI: 10.1007/bf01114938] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
We have identified and isolated two forms of insulin receptor from rat-liver plasma membranes. The smaller (Mr = 90k) is a single polypeptide. The same polypeptide appears to be the insulin-binding site of the larger Mr = 280k). Only the larger, multisubunit, receptor shows high-affinity binding of insulin and negative cooperativity in its dissociation kinetics.
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Kasuga M, Hedo JA, Yamada KM, Kahn CR. The structure of insulin receptor and its subunits. Evidence for multiple nonreduced forms and a 210,000 possible proreceptor. J Biol Chem 1982. [DOI: 10.1016/s0021-9258(18)34032-8] [Citation(s) in RCA: 152] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
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Im JH, Frangakis CJ, Meezan E, DiBona DR, Kim HD. Partial characterization of insulin receptors from rat myocytes. J Biol Chem 1982. [DOI: 10.1016/s0021-9258(18)33942-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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Olefsky JM, Marshall S, Berhanu P, Saekow M, Heidenreich K, Green A. Internalization and intracellular processing of insulin and insulin receptors in adipocytes. Metabolism 1982; 31:670-90. [PMID: 7045573 DOI: 10.1016/0026-0495(82)90197-4] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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Berhanu P, Olefsky JM, Tsai P, Thamm P, Saunders D, Brandenburg D. Internalization and molecular processing of insulin receptors in isolated rat adipocytes. Proc Natl Acad Sci U S A 1982; 79:4069-73. [PMID: 7051001 PMCID: PMC346578 DOI: 10.1073/pnas.79.13.4069] [Citation(s) in RCA: 63] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
The cellular fate of insulin receptors in isolated rat adipocytes was studied by using a biologically active photosensitive insulin derivative, B2(2-nitro-4-azidophenylacetyl)-des-PheB1-insulin (NAPA-DP-insulin), to photoaffinity label the insulin receptors. Insulin receptors specifically labeled with 125I-labeled NAPA-DP-insulin were identified by NaDodSO4/polyacrylamide gel electrophoresis and autoradiography. Under nonreducing conditions, specific bands of Mr 330,000, 295,000, and 260,000 were identified; under disulfide reducing conditions, these were converted into Mr 125,000 and 90,000 subunits. When cells labeled at 16 degrees C were immediately trypsinized, all of the receptor bands were degraded into lower molecular weight fragments, indicating that the labeled receptors were all on the cell surface. However, when the labeled cells were incubated at 37 degrees C for 1 hr prior to trypsin exposure, approximately equal to 30% of the receptors were found to be trypsin insensitive, indicating that this fraction was translocated intracellularly. Processing of the insulin receptors appeared to occur; incubation at 37 degrees C (but not at 16 degrees C) resulted in generation of a Mr 115,000 component from the Mr 125,000 subunit as well as in the disappearance of the Mr 330,000 and 295,000 species. Inclusion of chloroquine during photoaffinity labeling at 16 degrees C and during the subsequent incubation at 37 degrees C showed that this agent (i) increased the trypsin-insensitive (intracellular) receptor pool, (ii) blocked conversion of the Mr 125,000 subunit into the Mr 115,000 component, and (iii) prevented the disappearance of the Mr 330,000 and 295,000 species. These studies show that insulin-receptor complexes are internalized and processed intracellularly at a chloroquine-sensitive site(s).
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Deutsch PJ, Rosen OM, Rubin CS. Identification and characterization of a latent pool of insulin receptors in 3T3-L1 adipocytes. J Biol Chem 1982. [DOI: 10.1016/s0021-9258(19)83783-3] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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Fehlmann M, Carpentier JL, Le Cam A, Thamm P, Saunders D, Brandenburg D, Orci L, Freychet P. Biochemical and morphological evidence that the insulin receptor is internalized with insulin in hepatocytes. J Cell Biol 1982; 93:82-7. [PMID: 7040416 PMCID: PMC2112115 DOI: 10.1083/jcb.93.1.82] [Citation(s) in RCA: 89] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
There is morphological and biochemical evidence that insulin is internalized in hepatocytes. The present study was designed to investigate the fate of the insulin receptor itself, subsequently to the initial binding step of the hormone to the hepatocyte plasma membrane. The insulin receptor was labeled with a 125I-photoreactive insulin analogue (B2[2-nitro,4-azidophenylacetyl]des-PheB1-insulin). This photoprobe was covalently coupled to the receptor by UV irradiation of hepatocytes after an initial binding step of 2-4 h at 15 degrees C. At this temperature, only limited (approximately 20%) internalization of the ligand occurred. In a second step, hepatocytes were resuspended in insulin-free buffer and further incubated for 2-4 h at 37 degrees C. After h at 37 degrees C, no significant radioactivity could be detected in non-UV-irradiated cells, whereas 12-15 % of the radioactivity initially bound remained associated to UV-irradiated cells. Morphological analysis after electron microscopy revealed that approximately 70% of this radioactivity was internalized and preferentially associated with lysosomal structures. SDS PAGE analysis under reducing conditions revealed that most of the radioactivity was associated with a 130,000-dalton band, previously identified as the major subunit of the insulin receptor in a variety of tissues. Internalization of the labeled insulin-receptor complex at the end of the 37 degrees C incubation was further demonstrated by its inaccessibility to trypsin. Conversely, at the end of the association step, the receptor (also characterized as a predominant 130,000-dalton species) was localized on the cell surface since it was cleaved by trypsin. We conclude that in hepatocytes the insulin receptor is internalized with insulin.
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