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Manganese Acts upon Insulin/IGF Receptors to Phosphorylate AKT and Increase Glucose Uptake in Huntington's Disease Cells. Mol Neurobiol 2019; 57:1570-1593. [PMID: 31797328 DOI: 10.1007/s12035-019-01824-1] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2019] [Accepted: 10/24/2019] [Indexed: 12/14/2022]
Abstract
Perturbations in insulin/IGF signaling and manganese (Mn2+) uptake and signaling have been separately reported in Huntington's disease (HD) models. Insulin/IGF supplementation ameliorates HD phenotypes via upregulation of AKT, a known Mn2+-responsive kinase. Limited evidence both in vivo and in purified biochemical systems suggest Mn2+ enhances insulin/IGF receptor (IR/IGFR), an upstream tyrosine kinase of AKT. Conversely, Mn2+ deficiency impairs insulin release and associated glucose tolerance in vivo. Here, we test the hypothesis that Mn2+-dependent AKT signaling is predominantly mediated by direct Mn2+ activation of the insulin/IGF receptors, and HD-related impairments in insulin/IGF signaling are due to HD genotype-associated deficits in Mn2+ bioavailability. We examined the combined effects of IGF-1 and/or Mn2+ treatments on AKT signaling in multiple HD cellular models. Mn2+ treatment potentiates p-IGFR/IR-dependent AKT phosphorylation under physiological (1 nM) or saturating (10 nM) concentrations of IGF-1 directly at the level of intracellular activation of IGFR/IR. Using a multi-pharmacological approach, we find that > 70-80% of Mn2+-associated AKT signaling across rodent and human neuronal cell models is specifically dependent on IR/IGFR, versus other signaling pathways upstream of AKT activation. Mn2+-induced p-IGFR and p-AKT were diminished in HD cell models, and, consistent with our hypothesis, were rescued by co-treatment of Mn2+ and IGF-1. Lastly, Mn2+-induced IGF signaling can modulate HD-relevant biological processes, as the reduced glucose uptake in HD STHdh cells was partially reversed by Mn2+ supplementation. Our data demonstrate that Mn2+ supplementation increases peak IGFR/IR-induced p-AKT likely via direct effects on IGFR/IR, consistent with its role as a cofactor, and suggests reduced Mn2+ bioavailability contributes to impaired IGF signaling and glucose uptake in HD models.
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2
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Bryan MR, Bowman AB. Manganese and the Insulin-IGF Signaling Network in Huntington's Disease and Other Neurodegenerative Disorders. ADVANCES IN NEUROBIOLOGY 2017; 18:113-142. [PMID: 28889265 PMCID: PMC6559248 DOI: 10.1007/978-3-319-60189-2_6] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Huntington's disease (HD) is an autosomal dominant neurodegenerative disease resulting in motor impairment and death in patients. Recently, several studies have demonstrated insulin or insulin-like growth factor (IGF) treatment in models of HD, resulting in potent amelioration of HD phenotypes via modulation of the PI3K/AKT/mTOR pathways. Administration of IGF and insulin can rescue microtubule transport, metabolic function, and autophagy defects, resulting in clearance of Huntingtin (HTT) aggregates, restoration of mitochondrial function, amelioration of motor abnormalities, and enhanced survival. Manganese (Mn) is an essential metal to all biological systems but, in excess, can be toxic. Interestingly, several studies have revealed the insulin-mimetic effects of Mn-demonstrating Mn can activate several of the same metabolic kinases and increase peripheral and neuronal insulin and IGF-1 levels in rodent models. Separate studies have shown mouse and human striatal neuroprogenitor cell (NPC) models exhibit a deficit in cellular Mn uptake, indicative of a Mn deficiency. Furthermore, evidence from the literature reveals a striking overlap between cellular consequences of Mn deficiency (i.e., impaired function of Mn-dependent enzymes) and known HD endophenotypes including excitotoxicity, increased reactive oxygen species (ROS) accumulation, and decreased mitochondrial function. Here we review published evidence supporting a hypothesis that (1) the potent effect of IGF or insulin treatment on HD models, (2) the insulin-mimetic effects of Mn, and (3) the newly discovered Mn-dependent perturbations in HD may all be functionally related. Together, this review will present the intriguing possibility that intricate regulatory cross-talk exists between Mn biology and/or toxicology and the insulin/IGF signaling pathways which may be deeply connected to HD pathology and, perhaps, other neurodegenerative diseases (NDDs) and other neuropathological conditions.
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Affiliation(s)
- Miles R Bryan
- Department of Neurology, Vanderbilt University Medical Center, Nashville, TN, 37232, USA.
- Vanderbilt Brain Institute, Vanderbilt University Medical Center, Nashville, TN, 37232, USA.
- Department of Pediatrics, Vanderbilt University Medical Center, Nashville, TN, 37232, USA.
| | - Aaron B Bowman
- Department of Neurology, Vanderbilt University Medical Center, Nashville, TN, 37232, USA
- Vanderbilt Brain Institute, Vanderbilt University Medical Center, Nashville, TN, 37232, USA
- Department of Pediatrics, Vanderbilt University Medical Center, Nashville, TN, 37232, USA
- Vanderbilt Center in Molecular Toxicology, Vanderbilt University Medical Center, Nashville, TN, 37232, USA
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3
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Paxton R, Ye L. Regulation of heart insulin receptor tyrosine kinase activity by magnesium and spermine. Mol Cell Biochem 2005; 277:7-17. [PMID: 16132709 DOI: 10.1007/s11010-005-5755-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2004] [Accepted: 11/02/2004] [Indexed: 11/26/2022]
Abstract
Insulin action and aspects of the insulin-signaling pathway have been studied in the heart although the direct regulation of the heart's insulin receptor has not been explored. This study describes the first purification and characterization of the mammalian (rabbit, rat and bovine) heart insulin receptor. The rabbit heart IR showed maximum insulin binding of 18 microg/mg (approximately 1 mole insulin/mole (alpha2beta2) receptor) and a curvilinear Scatchard plot with a high affinity KD for insulin binding of approximately 4 nM at optimal pH (7.8) and NaCl concentration (150 mM). The insulin receptor tyrosine kinase activity was stimulated by insulin, Mg2+ (half-maximum response at approximately 5.6-10.6 nM and approximately 8.5 mM, respectively) and by the physiological polyamines, spermine and spermidine. The stimulation by Mg2+ and the polyamines occurred with and without insulin. These characteristics of the heart insulin receptor provide a mechanism for regulating the activity of the receptor's tyrosine kinase activity by the intracellular free Mg2+ concentration and the polyamines in the absence and presence of insulin.
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Affiliation(s)
- Ralph Paxton
- Laboratory of Metabolic Disorders, Auburn University, Auburn, AL 36849, USA.
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4
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Schäffer L, Brissette RE, Spetzler JC, Pillutla RC, Østergaard S, Lennick M, Brandt J, Fletcher PW, Danielsen GM, Hsiao KC, Andersen AS, Dedova O, Ribel U, Hoeg-Jensen T, Hansen PH, Blume AJ, Markussen J, Goldstein NI. Assembly of high-affinity insulin receptor agonists and antagonists from peptide building blocks. Proc Natl Acad Sci U S A 2003; 100:4435-9. [PMID: 12684539 PMCID: PMC153573 DOI: 10.1073/pnas.0830026100] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Insulin is thought to elicit its effects by crosslinking the two extracellular alpha-subunits of its receptor, thereby inducing a conformational change in the receptor, which activates the intracellular tyrosine kinase signaling cascade. Previously we identified a series of peptides binding to two discrete hotspots on the insulin receptor. Here we show that covalent linkage of such peptides into homodimers or heterodimers results in insulin agonists or antagonists, depending on how the peptides are linked. An optimized agonist has been shown, both in vitro and in vivo, to have a potency close to that of insulin itself. The ability to construct such peptide derivatives may offer a path for developing agonists or antagonists for treatment of a wide variety of diseases.
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5
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Lewis RE, Chaika OV. Therapeutic manipulation of the insulin receptor kinase - a review. Expert Opin Ther Pat 2000. [DOI: 10.1517/13543776.10.2.191] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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6
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Stith BJ, Woronoff K, Wiernsperger N. Stimulation of the intracellular portion of the human insulin receptor by the antidiabetic drug metformin. Biochem Pharmacol 1998; 55:533-6. [PMID: 9514089 DOI: 10.1016/s0006-2952(97)00540-6] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Our prior work suggested that the antidiabetic metformin must enter the cell to act and that the drug stimulates tyrosine kinase activity. We now report that therapeutic concentrations (approximately 1 microg/mL) of metformin stimulated the tyrosine kinase activity of the intracellular portion of the beta-subunit of the human insulin receptor (IPbetaIRK), the intracellular portion of the epidermal growth factor receptor and pp60-src, but not cAMP-dependent protein kinase. A derivative of metformin unable to lower glucose was ineffective in stimulating IPbetaIRK. Two derivatives more effective than metformin in patients were also more effective than metformin in stimulating IPbetaIRK. Higher levels (10-100 microg/mL) of metformin or methylglyoxyl bis(guanylhydrazone) inhibited the tyrosine kinases, and this inhibition may be responsible for the ability of these two drugs to block cell proliferation.
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Affiliation(s)
- B J Stith
- Department of Biology, University of Colorado-Denver, 80217, USA
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7
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Baron V, Gual P, Alengrin F, Van Obberghen E. Role of the insulin receptor C-terminal acidic domain in the modulation of the receptor kinase by polybasic effectors. EUROPEAN JOURNAL OF BIOCHEMISTRY 1996; 241:186-92. [PMID: 8898905 DOI: 10.1111/j.1432-1033.1996.0186t.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Basic polymers such as polylysine have been found to activate insulin receptor autophosphorylation and kinase activity toward substrates. It was suggested that acidic receptor domains may be involved in the interaction of the receptor with these basic effectors. In a previous study, we have shown that the receptor acid-rich C-terminal sequence, including residues 1270-1280, is involved in the regulation of the receptor kinase activity. Moreover, this domain may be the site of interaction with histone, which is a modulator of the receptor kinase. In this study, we investigated whether the insulin receptor domain comprising amino acids 1270-1280 is involved in the interaction with polybasic effectors. We used anti-peptide serum directed to this sequence, and basic activators such as polylysine, polyarginine and protamine sulfate. Our antibodies inhibit polylysine-induced receptor autophosphorylation, whereas they have no effect on receptor phosphorylation stimulated by concanavalin A which is a non-basic activator of the insulin receptor. Polylysine-induced receptor aggregation was blocked by the antibodies (Fab fragments or whole Ig), indicating that competition occurs between the antibody and polylysine at the level of their binding site to the receptor. Finally, we observed a direct interaction of the 125I-peptide corresponding to receptor sequence 1270-1280 with the basic polymers in dot-blot experiments. Interestingly, the peptide did not bind spermine, a basic molecule which is not an activator of the insulin receptor kinase. Our data indicate that the insulin receptor C-terminal acidic domain including residues 1270-1280 is involved in the interaction of polylysine and other polybasic molecules with the receptor. Since this receptor region has been implicated in the regulation of the receptor kinase activity, we propose that interaction of basic effectors with this domain may be responsible for their activating properties.
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Affiliation(s)
- V Baron
- Institut National de la Santé et de la Recherche Médicale (INSERM) U145, Faculté de Médecine, Nice, France
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8
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Cooper J, Conner J, Clements JB. Characterization of the novel protein kinase activity present in the R1 subunit of herpes simplex virus ribonucleotide reductase. J Virol 1995; 69:4979-85. [PMID: 7609068 PMCID: PMC189314 DOI: 10.1128/jvi.69.8.4979-4985.1995] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
We have compared the protein kinase activities of the R1 subunits from herpes simplex virus types 1 (HSV-1) and 2 (HSV-2) ribonucleotide reductase following expression in Escherichia coli. Autophosphorylation activity was observed when kinase assays were performed with immunoprecipitated R1 or proteins purified to homogeneity, and the activity was stimulated by the basic protein protamine. Transphosphorylation of histones or calmodulin by purified or immunoprecipitated HSV-1 and HSV-2 R1 was not observed, and our results suggest that the activities of these two proteins are similar. We further characterized the protein kinase activity of HSV-1 R1 by producing insertion and deletion mutants constructed with a plasmid expressing R1 amino acids 1 to 449. C-terminal deletion analysis identified the catalytic core of the enzyme as comprising residues 1 to 292, and this polypeptide will be useful for structural determinations by X-ray crystallography. Insertion of a 4-amino-acid sequence at sites within the protein kinase domain identified regions essential for activity; insertions at residues 22 and 112 completely inactivated activity, and an insertion at residue 136 reduced activity sixfold. Similar insertions at residues 257, 262, 292, and 343 had no effect on activity. The ATP analog 5'-fluorosulfonylbenzoyladenosine, which covalently modifies conventional eukaryotic kinases at an essential lysine residue within the active site, did label HSV R1, but this labelling occurred outside the N-terminal domain. These data indicate that the HSV R1 kinase is novel and distinct from other eukaryotic protein kinases.
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Affiliation(s)
- J Cooper
- MRC Virology Unit, Institute of Virology, Glasgow, United Kingdom
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9
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Sacks DB. Alteration of calmodulin-protein interactions by a monoclonal antibody to calmodulin. BIOCHIMICA ET BIOPHYSICA ACTA 1994; 1206:120-8. [PMID: 8186241 DOI: 10.1016/0167-4838(94)90080-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The effects of specific anti-calmodulin monoclonal antibodies on the conformation and interaction of calmodulin with two enzymes, the insulin receptor tyrosine kinase and casein kinase II, are examined. Addition of the anti-calmodulin antibody 2D1 in vitro augments phosphorylation of calmodulin by rat hepatocyte insulin receptors 4.9 +/- 0.5-fold (n = 7). Nonimmune immunoglobulin has no effect. Maximal phosphorylation is observed at a molar ratio of calmodulin:antibody of approx. 2:1, with higher concentrations of antibody producing lesser enhancement. Increasing Ca2+ concentrations in the physiological range progressively inhibit phosphorylation both in the absence and presence of antibody 2D1. Phosphate is incorporated predominantly on Tyr-99, which is distant from the antibody binding site. Enhancement of casein kinase II-catalyzed calmodulin phosphorylation is also produced by the antibody 2D1, implying that antibody binding induces a change in calmodulin conformation. In contrast, two other anti-calmodulin monoclonal antibodies, 4F4 and 4G2, decrease phosphorylation of calmodulin by both the insulin receptor kinase and casein kinase II. These data indicate that secondary and tertiary structures are important in enzyme-substrate interactions and suggest that the antibodies may be useful in investigating the mechanism of calmodulin function.
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Affiliation(s)
- D B Sacks
- Department of Pathology, Brigham and Women's Hospital, Boston, MA
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10
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Faria T, Blakesley V, Kato H, Stannard B, LeRoith D, Roberts C. Role of the carboxyl-terminal domains of the insulin and insulin-like growth factor I receptors in receptor function. J Biol Chem 1994. [DOI: 10.1016/s0021-9258(17)36736-4] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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11
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The role of COOH-terminal and acidic domains in the activity and stability of human insulin receptor protein tyrosine kinase studied by purified deletion mutants of the beta subunit domain. J Biol Chem 1993. [DOI: 10.1016/s0021-9258(18)41549-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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12
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Mohammadi M, Honegger A, Sorokin A, Ullrich A, Schlessinger J, Hurwitz DR. Aggregation-induced activation of the epidermal growth factor receptor protein tyrosine kinase. Biochemistry 1993; 32:8742-8. [PMID: 8395880 DOI: 10.1021/bi00085a004] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Various agents are able to stimulate the EGF receptor protein tyrosine kinase in the absence of ligand binding. To characterize their mechanism of action, we investigated their effects on the kinase activity of the intracellular domain of the EGF receptor (EGFR-IC). EGFR-IC (67 kDa) lacking the extracellular domain and transmembrane segment of the EGF receptor, but retaining kinase and autophosphorylation domains, was produced and purified as a soluble, cytoplasmic protein from Sf9 insect cells infected with a recombinant baculovirus. EGFR-IC was able to undergo autophosphorylation in a manner similar to full-length EGFR. Synthetic substrate peptides showed similar affinity to EGFR-IC as to the full-length receptor. The activity of the EGFR-IC was found to be dependent on divalent cations, Mn2+ being a more potent activator than Mg2+. Agents capable of aggregating the kinase by direct interaction (cross-linking antibodies, polycations) or through altering the surrounding solvent structure and thereby decreasing protein solubility [ammonium sulfate, poly(ethylene glycol), 2-methyl-2,4-pentanediol] activated the kinase in a manner which correlated with their ability to precipitate the EGFR intracellular domain. The widely different chemical nature of these agents suggests that they do not act by direct interaction with specific allosteric regulatory sites, but rather by facilitating the interactions between kinase molecules. These results support the hypothesis that full-length receptor aggregation itself, induced by ligand binding to the extracellular domain, results in intracellular domain interactions and the activation of kinase activity.
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Affiliation(s)
- M Mohammadi
- Department of Pharmacology, New York University Medical Center, New York 10016
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13
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Ospina B, Núñez A, Fernández-Renart M. Purification of a soluble casein kinase II from Dictyostelium discoideum lacking the beta subunit: regulation during proliferation and differentiation. Mol Cell Biochem 1992; 118:49-60. [PMID: 1488055 DOI: 10.1007/bf00249694] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
A type II casein kinase has been purified from the soluble fraction of Dictyostelium discoideum vegetative cells. The enzyme has been purified 370 fold and behaves catalytically as casein kinase type II, in the sense that it utilizes GTP as well as ATP as phosphoryl donors, it is inhibited by low heparin concentrations and phosphorylates a specific peptide for CK II. It is a tetramer of 38 kDa-subunits with catalytic activity and ability to autophosphorylate in vitro. The comparison of this activity with the nuclear enzyme previously purified from the same organism indicates that both have the same molecular structure. Both enzymes have antigenic determinants in common with casein kinase II from bovine thymus, suggesting a high degree of conservation during evolution. Studies on the activity of this enzyme during early differentiation, and in the transition from quiescence to proliferation shows an increase in specific activity suggesting a crucial role for the enzyme in this organism.
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Affiliation(s)
- B Ospina
- Departamento de Bioquímica, Facultad de Medicina, U.A.M., Madrid, Spain
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14
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Sacks DB, McDonald JM. Effects of cationic polypeptides on the activity, substrate interaction, and autophosphorylation of casein kinase II: a study with calmodulin. Arch Biochem Biophys 1992; 299:275-80. [PMID: 1444466 DOI: 10.1016/0003-9861(92)90275-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The effects of basic polypeptides on the ability of casein kinase II to phosphorylate an exogenous substrate (calmodulin) are correlated with steady-state autophosphorylation of the alpha- and beta-subunits of casein kinase II. Polylysine and polyarginine increase autophosphorylation of the alpha-subunit with a concomitant decrease in beta-subunit phosphorylation, while enhancing casein kinase II-stimulated phosphorylation of calmodulin over 100-fold. The highly basic carboxyl terminal segment of the endogenous p21c-Ki-ras has similar effects on the phosphorylation of calmodulin and the alpha- and beta-subunits of casein kinase II. Altering the concentration of cationic polypeptides produces a biphasic effect on the phosphorylation of both calmodulin and the alpha-subunit, which correlate positively with each other but do not correlate with beta-subunit phosphorylation. When the KCl concentration is changed, casein kinase II activity correlates positively only with alpha-subunit phosphorylation. In contrast, the biphasic response of calmodulin phosphorylation by casein kinase II at different Ca2+ concentrations correlates positively with both alpha- and beta-subunit phosphorylation. Therefore, in the presence of basic protein activators, the rate of phosphorylation of a substrate, calmodulin, correlates with steady-state phosphorylation of the alpha-subunit, but not with the beta-subunit under all conditions tested. Endogenous cationic factors may modulate the in vivo activity of casein kinase II and alter the interaction of the enzyme with specific intracellular substrates.
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Affiliation(s)
- D B Sacks
- Department of Pathology, Brigham & Women's Hospital, Boston, Massachusetts 02115
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15
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McGlynn E, Becker M, Mett H, Reutener S, Cozens R, Lydon NB. Large-scale purification and characterisation of a recombinant epidermal growth-factor receptor protein-tyrosine kinase. Modulation of activity by multiple factors. EUROPEAN JOURNAL OF BIOCHEMISTRY 1992; 207:265-75. [PMID: 1321046 DOI: 10.1111/j.1432-1033.1992.tb17047.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The human epidermal-growth-factor receptor (EGF-R) is a 170-kDa transmembrane glycoprotein that mediates the mitogenic response of cells to EGF and transforming growth factor alpha. Culture conditions have been developed for the large-scale expression of the cytoplasmic domain of the EGF-R in insect cells using a recombinant baculovirus. From 61 Sf9 cells, grown to high density using a bioreactor, 20 mg of the EGF-R kinase was purified to greater than 95% purity. Purification, which was carried out in the absence of detergents using classical purification methods, yielded an EGF-R protein that was not phosphorylated on tyrosine. This procedure has enabled us to produce high quality enzyme for both structural and biochemical studies on the EGF-R kinase. The in vitro activity of the cytoplasmic domain of the EGF-R kinase was modulated by multiple assay factors which include substrates, divalent cations and conformational modulators. Kinetic analysis in the presence of Mn2+ gave an apparent Vmax value of 20 nmol min-1 mg-1 and Km values of 4.5 microM for ATP and 1.43 mM for angiotensin II. This corresponds to a turnover number of 1.4 mol min-1 mol-1. Ammonium sulfate (1 M) resulted in an eightfold stimulation of kinase activity when assayed using angiotensin II as substrate. The specific activity of the intracellular domain of the EGF-R, when assayed at 20 degrees C in the presence of 1M ammonium sulfate, was 160 nmol min-1 mg-1. Activation of the EGF-R kinase by ammonium sulfate was found to be substrate-specific. No activation was found when assayed using polymeric substrates. Addition of Me(2+)-ATP to the purified enzyme resulted in autophosphorylation and was accompanied by retardation of SDS/PAGE migration. Kinetic constants and metal ion preferences of a number of co-polymers and peptide substrates have been compared. Dramatic differences in kinetic constants were found which were dependent on both the substrate and metal ion used. Activation of EGF-R autophosphorylation was found to be influenced by the use of charged polymers. The random polymer of Glu, Lys, Ala, Tyr (2:5:6:1), which was not phosphorylated by the EGF-R kinase, dramatically activates autophosphorylation of the EGF-R. Thus the intracellular domain of the EGF-R appears to be in a low-activity conformation which, under appropriate assay conditions, can be activated to a similar specific activity to that reported for the purified EGF-R holoenzyme.
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Affiliation(s)
- E McGlynn
- Research Department, Ciba-Geigy Ltd., Basel, Switzerland
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16
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Luo J, Aurelian L. The transmembrane helical segment but not the invariant lysine is required for the kinase activity of the large subunit of herpes simplex virus type 2 ribonucleotide reductase (ICP10). J Biol Chem 1992. [DOI: 10.1016/s0021-9258(19)50139-9] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
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17
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Donella-Deana A, Marin O, Brunati AM, Pinna LA. Selective effect of poly(lysine) on the enhancement of the lyn tyrosine protein kinase activity. Increased specificity toward src peptides. ACTA ACUST UNITED AC 1992; 204:1159-63. [PMID: 1372554 DOI: 10.1111/j.1432-1033.1992.tb16742.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A tyrosine protein kinase (TPK-I), isolated from rat spleen [Brunati, A. M. & Pinna, L. A. (1988) Eur. J. Biochem. 172, 451-457] and recently identified as the product of the lyn oncogene [Brunati, A. M., Donella-Deana, A., Ralph, S., Marchiori, F., Borin, G., Fischer, S. & Pinna, L. A. (1991) Biochim. Biophys. Acta 1901, 123-126], is stimulated by a variety of effectors, including poly(lysine), heparin and very high NaCl concentrations. The efficacy of these compounds is variably dependent on the nature of the phosphoacceptor peptide substrates. Here we show that poly(lysine), but neither NaCl nor heparin, specifically enhances the phosphorylation efficiency of lyn TPK for the peptide EDNEYTA (src peptide). It reproduces the main autophosphorylation site of pp60c-src (Tyr416), which is entirely conserved in lyn TPK. The favourable effect of poly(lysine) is accounted for by both a dramatic drop of the Km value (70 microM versus 670 microM) and more than a threefold increase in Vmax. The effect is not so evident with a variety of different peptides, either unrelated to the src peptide (e.g. angiotensin II, AAYAA) or derived from the src peptide by single or multiple substitutions of the residues located on the N-terminal side of tyrosine. In particular, the responsiveness to poly(lysine) is dramatically reduced whenever alanine is replaced for either asparagine at position -2 or glutamic acid at position -1, either in the src heptapeptide or in its shorter derivative, the pentapeptide NEYTA. In sharp contrast, the favourable effect of 2 M NaCl, which is invariably accounted for only by an increased Vmax, is especially evident with peptides like angiotensin II and AAYAA, whose phosphorylation is less sensitive to poly(lysine) stimulation. The phosphorylation of the src peptides are actually inhibited rather than stimulated by 2 M NaCl. Consistent with this, lyn TPK autophosphorylation is also dramatically stimulated by poly(lysine) while being inhibited by 2 M NaCl. These data show that poly(lysine) deeply alters the selectivity of lyn TPK by conferring to it an enhanced activity and an especially high affinity toward peptides that reproduce the conserved autophosphorylation site of the TPK of the src family. It is suggested that endogenous compound, whose effect is mimicked by poly(lysine) in vitro, may play a relevant role in determining the specificity of lyn TPK in vivo and possibly of other TPK of the src family.
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Affiliation(s)
- A Donella-Deana
- Dipartimento di Chimica Biologica, Università di Padova, Italy
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18
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Lee AW. Signal transduction by the colony-stimulating factor-1 receptor; comparison to other receptor tyrosine kinases. CURRENT TOPICS IN CELLULAR REGULATION 1992; 32:73-181. [PMID: 1318184 DOI: 10.1016/b978-0-12-152832-4.50005-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- A W Lee
- Clinical Hematology Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland 20892
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19
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Racker E. Chaperones and matchmakers: inhibitors and stimulators of protein phosphorylation. CURRENT TOPICS IN CELLULAR REGULATION 1992; 33:127-43. [PMID: 1354148 DOI: 10.1016/b978-0-12-152833-1.50013-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- E Racker
- Section of Biochemistry, Molecular and Cell Biology, Cornell University, Ithaca, New York 14853
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20
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Tartare S, Ballotti R, Van Obberghen E. Interaction between heterologous receptor tyrosine kinases. Hormone-stimulated insulin receptors activate unoccupied IGF-I receptors. FEBS Lett 1991; 295:219-22. [PMID: 1662646 DOI: 10.1016/0014-5793(91)81422-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
To determine whether heterologous receptor tyrosine kinases interact with each other we have investigated the ability of insulin receptors to transphosphorylate and transactivate IGF-I receptors. Using partially purified receptors we show that hormone-stimulated insulin receptors induced a 40% increase in IGF-I receptor phosphorylation. Remarkably, this transphosphorylation of IGF-I receptors by insulin receptors resulted in a 2.5-fold augmentation of the IGF-I receptor tyrosine kinase activity for substrates. Our findings demonstrate that transphosphorylation with transactivation can occur between insulin and IGF-I receptors. We would like to propose that such a phenomenon participates in the insulin-induced pleiotropic program by mediating the growth promoting effects of the hormone.
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Affiliation(s)
- S Tartare
- Institut National de la Santé et de la Recherche Médicale, INSERM U145, Faculté de Médecine, Nice, France
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21
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Polylysine increases the number of insulin binding sites in soluble insulin receptor preparations. J Biol Chem 1991. [DOI: 10.1016/s0021-9258(19)47382-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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22
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Abstract
How sperm initiate egg development is being investigated with gametes of the marine worm Urechis. Sperm acrosomal protein, previously shown to activate eggs (Gould et al., 1986, Dev. Biol. 117, 306-318; Gould and Stephano, 1987, Science 235, 1654-1656), was enzymatically cleaved into soluble peptide fragments. When this mixture was added to eggs they activated, and parthenogenetic cleavage often occurred. An active peptide (P23) was purified from the mixture and its sequence was determined to be Val-Ala-Lys-Lys-Pro-Lys. Synthetic peptide had the same biological activity. P23 induced eggs to undergo the complete sequence of changes that normally follows fertilization, including the fertilization potential, completion of meiosis, and DNA replication. When a sperm centrosome was introduced into eggs by prefertilization without activation, and the eggs were subsequently activated by P23, they developed normally to trochophore larvae (the contribution of another sperm component is not ruled out by this experiment). P23 covalently coupled to bovine serum albumin also activated eggs, showing that it acted on the external surface of the egg. The peptide did not activate sea urchin eggs, but did cause oyster eggs to undergo germinal vesicle breakdown.
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Affiliation(s)
- M C Gould
- Facultad de Ciencias, Universidad Autónoma de Baja California, Ensenada, México
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23
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Synthetic fragments of the CD4 receptor cytoplasmic domain and large polycations alter the activities of the pp56lck tyrosine protein kinase. J Biol Chem 1991. [DOI: 10.1016/s0021-9258(18)98538-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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24
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Haber MT, Fukui T, Lebowitz MS, Lowenstein JM. Activation of phosphoinositide-specific phospholipase C delta from rat liver by polyamines and basic proteins. Arch Biochem Biophys 1991; 288:243-9. [PMID: 1654825 DOI: 10.1016/0003-9861(91)90191-k] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Phospholipase C from rat liver with a molecular weight of 87,000 (PLC delta) is stimulated by polyamines, basic proteins, and basic polyamino acids. The activation occurs in both the presence and the absence of detergents. Half-maximum activation by spermine is observed at 0.15 mM, with optimum effects between 0.2 and 0.5 mM. Spermine inhibits above 0.5 mM. Half-maximum activation by spermidine and putrescine is observed at 0.9 and 6 mM, respectively, with optimum effects at 2 and 5 mM, respectively. These polyamines also inhibit at higher concentrations. Neomycin activates the enzyme with an optimum concentration of 10 microM, but maximum activation is less than with polyamines. Half-maximum activation by histone 2B occurs at 0.5 micrograms/ml (36 nM), with maximum stimulation at 1.5 micrograms/ml. Other histones, protamine, melittin, poly-L-ornithine, poly-L-lysine, poly-D-lysine, and poly-L-arginine, activate optimally at 3-10 micrograms/ml. Myelin basic protein and lysozyme activate optimally at 50-100 micrograms/ml. Typical activations are three- to eightfold, but under some conditions the enzyme shows little or no activity in the absence of basic activators. The basic activators lower the salt concentration required for maximal activity. In the case of the detergent-micelle assay, histone shifts the optimum NaCl concentration from 350 to 200 mM for PIP2, from 260 to 100 mM for PIP, and from 150 to 0 mM for PI. Histone potentiates the activation by Ca2+, but does not shift the optimum Ca2+ concentration. The optimum salt and Ca2+ concentrations are linked, such that a decrease in the concentration of one decreases the optimum concentration of the other. Activation by histone is diminished by MgCl2 in a concentration-dependent manner.
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Affiliation(s)
- M T Haber
- Graduate Department of Biochemistry, Brandeis University, Waltham, Massachusetts 02254
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25
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Affiliation(s)
- P Nissley
- Endocrinology Section, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892
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26
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Biener Y, Zick Y. Basic polycations activate the insulin receptor kinase and a tightly associated serine kinase. EUROPEAN JOURNAL OF BIOCHEMISTRY 1990; 194:243-50. [PMID: 1701386 DOI: 10.1111/j.1432-1033.1990.tb19449.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The effects of cationic polyamino acids on phosphorylation of the insulin and insulin-like growth factor 1 receptor kinases were studied and the following observations were made. (a) Polylysine stimulated both tyrosine and serine phosphorylation of the insulin receptor and of additional proteins present in lectin-purified membrane preparations from rat liver. (b) Polylysine synergized with insulin to enhance phosphorylation of the insulin receptor and of additional proteins (pp40 and pp110). (c) Polylysine effects were more pronounced upon increasing the polylysine chain length. (d) The effect of polylysine was biphasic with an optimum at 100 micrograms/ml. (e) Polylysine was found ineffective in stimulating the phosphorylation of immobilized insulin receptors. Taken together, these findings support the notion that the action of polylysine involves conformational changes and presumably aggregation of soluble receptors. The same effects of polylysine were obtained with highly purified insulin receptor preparations. Under these conditions polylysine enhanced both serine and tyrosine phosphorylation of the insulin receptor, suggesting that polylysine stimulates the activity of the insulin receptor kinase, and of a serine kinase that is tightly associated with the insulin receptor.
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Affiliation(s)
- Y Biener
- Department of Chemical Immunology, Weizmann Institute of Science, Rehovot, Israel
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27
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Chung TD, Wymer JP, Kulka M, Smith CC, Aurelian L. Myristylation and polylysine-mediated activation of the protein kinase domain of the large subunit of herpes simplex virus type 2 ribonucleotide reductase (ICP10). Virology 1990; 179:168-78. [PMID: 2171204 DOI: 10.1016/0042-6822(90)90286-z] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The amino-terminal domain of the large subunit of herpes simplex virus type 2 (HSV-2) ribonucleotide reductase (ICP10) was previously shown to possess protein kinase (PK) activity that localizes to the cytosolic, cytoskeletal, and plasma membrane fractions. Further studies of the PK domain using computer-assisted sequence analysis have identified a single transmembrane segment and fatty acid incorporation findings indicate that ICP10 is myristylated. Myristylation does not depend on a viral enzyme, since myristic acid is incorporated into ICP10 precipitated from cells transfected with an ICP10 expression vector. It is also incorporated into the 57-kDa protein expressed by the amino-terminal PK expression vector. The myristyl moiety is linked through an amide bond. The basic protein polylysine stimulates the kinase activity and alters its divalent cation requirements resulting in 20- to 40-fold stimulation in the presence of 0.1 mM Mn2+. The PK activity is inhibited by antibody to synthetic peptides corresponding to residues 355-369 and 13-26, respectively, located within, and amino-terminal to, the predicted PK catalytic domain.
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Affiliation(s)
- T D Chung
- Department of Pharmacology and Experimental Therapeutics, University of Maryland School of Medicine, Baltimore 21201
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28
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Kyriakis JM, Avruch J. pp54 microtubule-associated protein 2 kinase. A novel serine/threonine protein kinase regulated by phosphorylation and stimulated by poly-L-lysine. J Biol Chem 1990. [DOI: 10.1016/s0021-9258(17)44910-6] [Citation(s) in RCA: 111] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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29
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O'Hare T, Pilch PF. Intrinsic kinase activity of the insulin receptor. THE INTERNATIONAL JOURNAL OF BIOCHEMISTRY 1990; 22:315-24. [PMID: 2159922 DOI: 10.1016/0020-711x(90)90132-m] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Since the identification of the insulin receptor by insulin-binding activity almost two decades ago, our understanding of the structure and function of the insulin receptor has progressed tremendously. The importance of the intrinsic tyrosine protein kinase activity of the insulin receptor is implied by the fact that the insulin receptor belongs to a family of receptor tyrosine kinases which play a role in growth control, by experiments demonstrating the intimate association of normal kinase activity and insulin action, and by evidence that the intrinsic kinase activity can be regulated under certain conditions. There are still some major gaps in our knowledge concerning the structure/function of the insulin receptor such as how activation of the intrinsic kinase activity of the receptor leads to altered cellular physiology. The kinase may phosphorylate endogenous substrates or autophosphorylation may simply alter beta subunit conformation so it can then interact with an effector system (i.e. a serine kinase) directly, or indirectly through a G-protein. The truth may lie somewhere between these two pathways.
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Affiliation(s)
- T O'Hare
- Department of Biochemistry K404, Boston University Medical School, MA 02118
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30
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Goren HJ, Neufeld E, Boland D. A 180,000 molecular weight glycoprotein substrate of the insulin receptor tyrosine kinase is present in human placenta and in rat liver, muscle, heart and brain plasma membrane preparations. Cell Signal 1990; 2:537-55. [PMID: 1964389 DOI: 10.1016/0898-6568(90)90076-m] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Cell signalling for insulin may include insulin receptor tyrosine kinase catalysing the phosphorylation of one or more cell proteins. Since temporally the insulin receptor will encounter plasma membrane proteins first, we have studied the in vitro phosphorylation of purified plasma membrane preparations. Two proteins were immunoprecipitated with anti-phosphotyrosine antibody from rat liver, muscle, heart and brain membranes and from human placenta membranes: the insulin receptor (detected as a phosphorylated-beta-subunit) and a 180,000 molecular weight protein (pp180). pp180 is a monomeric glycoprotein that in the absence of dithiothreitol migrated in denaturing gels like a 150,000 molecular weight protein. pp180 was a substrate for the insulin receptor: (i) receptor and pp180 phosphorylation followed a similar insulin dose-response, although fold-stimulation of autophosphorylation was greater; and (ii) removal of insulin receptors with monoclonal antibodies prevented subsequent pp180 phosphorylation. Insulin-activated receptors increased the extent, but not the rate, of pp180 phosphorylation; the increased phosphate was incorporated into tyrosine and appeared to do so in three or four of pp180's 12 tryptic phosphopeptides. Some data suggest that pp180 is the same protein in each of the tested tissues. The occurrence of pp180, an insulin receptor substrate, in plasma membranes of several insulin responsive tissues suggests that it has a role in insulin signalling.
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Affiliation(s)
- H J Goren
- Department of Medical Biochemistry, Faculty of Medicine, University of Calgary, Alberta, Canada
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31
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Kohanski RA. Insulin Receptor Aggregation and Autophosphorylation in the Presence of Cationic Polyamino Acids. J Biol Chem 1989. [DOI: 10.1016/s0021-9258(19)30033-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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