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Ribatti D. Lelio Orci, the modern master of morphology. Cell Biol Int 2019; 43:846-851. [PMID: 31115951 DOI: 10.1002/cbin.11178] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Accepted: 05/18/2019] [Indexed: 11/10/2022]
Abstract
Lelio Orci has made seminal contributions to our understanding of pancreatic islet structure and function. He introduced quantitative criteria to structural analysis in the study of endocrine pancreas in a series of works performed in collaboration with Albert Renold, Roger Unger, and Donald Steiner. Orci has moved islet cell morphology from the primitive era of histochemistry and electron microscopy into the modern era of cell biology, applying the most advanced techniques and covering every aspect of normal and pathological structure-function relationships. In collaboration with James Rothman in New York and Randy Schekman in Berkley, Orci discovered that the transport steps from the endoplasmic reticulum to the Golgi complex, and within the Golgi, are mediated by two sets of vesicles coated with protein envelopes different from clathrin.
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Affiliation(s)
- Domenico Ribatti
- Department of Basic Medical Sciences, Neurosciences and Sensory Organs, University of Bari Medical School, 70124 Bari, Italy
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Preza GC, Pinon R, Ganz T, Nemeth E. Cellular catabolism of the iron-regulatory peptide hormone hepcidin. PLoS One 2013; 8:e58934. [PMID: 23536837 PMCID: PMC3594189 DOI: 10.1371/journal.pone.0058934] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2012] [Accepted: 02/08/2013] [Indexed: 11/18/2022] Open
Abstract
Hepcidin, a 25-amino acid peptide hormone, is the principal regulator of plasma iron concentrations. Hepcidin binding to its receptor, the iron exporter ferroportin, induces ferroportin internalization and degradation, thus blocking iron efflux from cells into plasma. The aim of this study was to characterize the fate of hepcidin after binding to ferroportin. We show that hepcidin is taken up by ferroportin-expressing cells in a temperature- and pH-dependent manner, and degraded together with its receptor. When Texas red-labeled hepcidin (TR-Hep) was added to ferroportin-GFP (Fpn-GFP) expressing cells, confocal microscopy showed co-localization of TR-Hep with Fpn-GFP. Using flow cytometry, we showed that the peptide was almost completely degraded by 24 h after its addition, but that lysosomal inhibitors completely prevented degradation of both ferroportin and hepcidin. In addition, using radio-labeled hepcidin and HPLC analysis we show that hepcidin is not recycled, and that only degradation products are released from the cells. Together these results show that the hormone hepcidin and its receptor ferroportin are internalized together and trafficked to lysosomes where both are degraded.
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Affiliation(s)
- Gloria Cuevas Preza
- Department of Dermatology, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
| | - Rogelio Pinon
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, California, United States of America
| | - Tomas Ganz
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, California, United States of America
- Department of Pathology, David Geffen School of Medicine, University of California, Los Angeles, California, United States of America
| | - Elizabeta Nemeth
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, California, United States of America
- * E-mail:
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3
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Cytomorphological aspects on the response of the branchial heart complex of Sepia officinalis L. (cephalopoda) to xenobiotics and bacterial infection. Tissue Cell 1998; 30:662-71. [DOI: 10.1016/s0040-8166(98)80085-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/1998] [Accepted: 08/06/1998] [Indexed: 11/20/2022]
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Abstract
The frog taste disc (TD) is apparently the largest gustatory organ found in vertebrates and seems to differentiate into a specialized variety of the prototypic scheme of the taste bud. An explanation for this unusual organization is lacking although it is possible to speculate the existence of environmental and nutritional requirements. Up to the present time, the most common model of the TD was based on two main cell types (sensory and sustentacular). This model may oversimplify the morphology of this structure since more numerous cell types have been described. We now propose a new model of the TD, based on comprehensive data on the ultrastructure of the organ obtained in the last 20 years. The main conclusions are the following: (1) the TD is a pluristratified epithelium with a general organization similar to that of the olfactory and vomeronasal epithelium; (2) it has skeleton composed of three different types of epithelial cells; (3) the chemoreceptorial surface is covered by different microenvironments; (4) three different types of neuro-epithelial systems are present; the type II is an 'open' sensory cell with axonal contacts devoid of vesicles; the type III is an 'open' sensory cell with synaptic-like junctions; the type i.v. is a 'closed' sensory cell with a 'Merkel-neurite complex'; (5) the nerve fibers in the basal plexus are mostly cholinergic while the peridiscal nerve fibers are mostly peptidergic. The presence of several cell types in the TD must be considered using these large receptors in electrophysiological studies or as a source of isolated cells, and their complexity must induce caution in the interpretation of the data. Text books of histology usually describe the peripheral structures associated with taste as very simple: an idea that probably must be revised. A taste organ is a highly complex structure composed of several sensory systems and a comparative approach can aid comprehension of its general organization. The study of the 'large taste organs' present in some species of amphibians can provide useful data for knowledge of the gustatory system of vertebrates.
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Affiliation(s)
- F Osculati
- Institute of Human Anatomy and Histology, Verona, Italy
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5
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Mirossay L, Di Gioia Y, Chastre E, Emami S, Gespach C. Pharmacological control of gastric acid secretion: Molecular and cellular aspects. Biosci Rep 1992; 12:319-68. [PMID: 1363275 DOI: 10.1007/bf01121499] [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: 11/29/2022] Open
Affiliation(s)
- L Mirossay
- Institut National de la Santé et de la Recherche Médicale INSERM U. 55, Unité de Recherches sur les Peptides Neurodigestifs et le Diabète, Hôpital Saint-Antoine, Paris, France
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Casey CA, Camacho KB, Tuma DJ. The effects of chronic ethanol administration on the rates of internalization of various ligands during hepatic endocytosis. BIOCHIMICA ET BIOPHYSICA ACTA 1992; 1134:96-104. [PMID: 1554752 DOI: 10.1016/0167-4889(92)90032-7] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The purpose of the present study was to further characterize the ethanol-induced impairments in hepatic endocytosis. Specifically, we examined the effects of ethanol treatment on receptor-ligand internalization via the coated and noncoated pit pathways. Insulin, epidermal growth factor (EGF) and asialoorosomucoid (ASOR) were used as model ligands to study internalization by isolated hepatocytes. ASOR and EGF are thought to be internalized strictly in coated pit regions of the cell membrane, while insulin may be internalized in both coated and uncoated membrane regions. Ethanol administration for 5-7 weeks decreased internalization of ASOR and EGF while internalization of insulin was unchanged during a single round of endocytosis of surface-bound ligand. Similarly, a more quantitative measure of endocytosis, the endocytic rate constant, was decreased for EGF and ASOR but not for insulin in livers of experimental rats. When endocytosis of Lucifer yellow, a fluorescent dye known to be internalized in the cell by fluid-phase endocytosis was examined, the initial rates of dye uptake were not significantly altered by alcohol administration. These results indicate that ethanol may selectively impair internalization occurring by coated pits while it has a minimal effect on initial uptake of molecules which are internalized by noncoated membrane regions.
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Affiliation(s)
- C A Casey
- Liver Study Unit, Department of Veterans Affairs Medical Center, Omaha, NE 68105
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Leckett B, Germinario RJ. Construction of a toxic insulin molecule: selection and partial characterization of cells resistant to its killing effects. Cytotechnology 1992; 10:125-36. [PMID: 1369208 DOI: 10.1007/bf00570889] [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: 10/26/2022] Open
Abstract
We have constructed an insulin-diphtheria hormono-toxin which migrates as a single 29 kd band on 10% SDS polyacrylamide gel electrophoresis. This corresponds to a one to one molar ratio of the diphtheria A-chain (23 kDa) and insulin (6 kDa) molecules. The diphtheria A-chain: insulin (DTaI) hormono-toxin demonstrates cytotoxicity in V-79 Chinese hamster cells exhibiting an LD50 of 1.1 x 10(-8) M, which is 22 x more potent than whole diphtheria toxin. Also, DTaI can competitively displace [125I]-insulin with an ED50 of 1.1 x 10(-8) M, which is identical to the ED50 of insulin (1.1 x 10(-8) M) and showed limited cross-reactivity with the IGF-1 receptor (12% displacement of [125I]-IGF-1 with a DTaI concentration of 1.1 x 10(-8) M). We have used DTaI to select conjugate-resistant clones from the V-79 Chinese hamster fibroblast parental cell line. Conjugate-resistant variants expressed insulin binding levels ranging from 8.0 +/- 2.0 fmoles/mg protein down to 3.6 +/- 0.5 fmoles/mg protein while insulin binding in the V-79 parental cell line was 11.2 +/- 0.2 fmoles/mg protein. Additionally, a number of conjugate resistant clones expressed variable ability to grow in medium containing 5% serum. The altered ability of these clones to grow in a serum-containing medium did not correlate directly with the changes observed for insulin binding. One mutant, IV-A1-j, did not grow in a serum-free defined medium containing insulin as the predominant mitogen. This IV-A1-j mutant had a lower number of insulin receptors, no change in insulin binding affinity, no change in the rate of internalization of [125I]-insulin and no apparent difference in [125I]-IGF-1 binding. Further, insulin-stimulated sugar transport was similar to that observed in the parental cell line. Based on these observations we suggest that 1) DTaI elicits its cytotoxicological effects through the insulin receptor trafficking pathway, 2) DTaI can be used to isolate cells altered at the level of insulin binding and/or action, and 3) signal transduction mechanisms responsible for mediating insulin-dependent cell growth can be pursued using mutants such as IV-A1-j.
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Affiliation(s)
- B Leckett
- Lady Davis Institute for Medical Research, Sir Mortimer B. Davis - Jewish General Hospital, Montreal, Quebec, Canada
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Tuma DJ, Casey CA, Sorrell MF. Chronic ethanol-induced impairments in receptor-mediated endocytosis of insulin in rat hepatocytes. Alcohol Clin Exp Res 1991; 15:808-13. [PMID: 1755513 DOI: 10.1111/j.1530-0277.1991.tb00606.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The effects of chronic ethanol administration on the receptor-mediated endocytosis of insulin were investigated in isolated hepatocytes. When hepatocytes were isolated from rats that were fed an ethanol liquid diet for 5-6 weeks, these cells bound 25% less insulin to their surface membrane than did cells from the chow-fed or pair-fed controls. This decreased binding was likely a result of reduced surface receptor number rather than changes in receptor affinity. Rates of insulin degradation were also reduced by 25-30% in hepatocytes from the ethanol-fed animals. In addition, chronic ethanol feeding induced a defect in the internalization of the receptor-insulin complex and altered the hepatocellular processing of the internalized insulin. These results indicate that chronic ethanol administration impairs both the surface binding and the endocytosis of insulin by the liver.
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Affiliation(s)
- D J Tuma
- Liver Study Unit, Department of Veterans Affairs Medical Center, Omaha, NE 68105
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Richter WO, Jacob BG, Schwandt P. Insulin inhibits lipolytic activity and degradation of beta-lipotropin in rabbit adipose tissue. REGULATORY PEPTIDES 1990; 29:257-66. [PMID: 2217905 DOI: 10.1016/0167-0115(90)90088-e] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
beta-Lipotropin, a pituitary peptide, is a potent stimulator of lipolysis in rabbit adipose tissue in vitro and in vivo. Insulin inhibited the beta-lipotropin (1-100 nM)-stimulated glycerol release from rabbit adipocytes and fat pads significantly at concentrations of 10 and 100 microM. Both these concentrations of insulin also decreased the degradation of beta-lipotropin in intact adipose tissue to the same extent as the lipolytic activity. Furthermore, insulin reduced the degradation of beta-lipotropin in rabbit adipose tissue homogenate. Like insulin, several lysosomotropic agents also decreased significantly the degradation and the lipolytic activity of beta-lipotropin. On the other hand, insulin-like growth factor I in lower concentrations (1-100 nM) did not effect degradation and lipolytic activity of beta-lipotropin in rabbit adipose tissue. Thus, a direct influence of insulin on lysosomal enzymes degrading beta-lipotropin in rabbit adipose tissue can be suggested.
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Affiliation(s)
- W O Richter
- Department of Medicine II, University of Munich, F.R.G
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Geiger D, Carpentier JL, Gorden P, Orci L. Down-regulation of insulin receptors is related to insulin internalization. Exp Cell Res 1989; 185:33-40. [PMID: 2680540 DOI: 10.1016/0014-4827(89)90034-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
In the present study, we have tested the influence of inhibition of endocytosis by hypertonic medium on the regulation of cell surface insulin receptors. We show that active internalization of 125I-insulin is markedly inhibited by hypertonic media and that, in parallel, cell surface invaginations are significantly diminished. These two events are accompanied by a marked inhibition of cell surface insulin receptor down-regulation. These data provide further strong evidence that receptor-mediated endocytosis is the major mechanism by which insulin receptors are regulated at the surface of target cells.
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Affiliation(s)
- D Geiger
- Institute of Histology and Embryology, University of Geneva Medical Center, Switzerland
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Immunohistochemical study of insulin receptors of the liver. Bull Exp Biol Med 1989. [DOI: 10.1007/bf00841748] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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12
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Mogensen KE, Uzé G, Eid P. The cellular receptor of the alpha-beta interferons. EXPERIENTIA 1989; 45:500-8. [PMID: 2525481 DOI: 10.1007/bf01990498] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
This is a selective review of recent trends in research on the cellular receptor for the alpha-beta interferons. It deals mainly with work published in the last three years (1985-88), and therefore mainly with receptors for the human interferons. The binding characteristics of several human alpha interferons are examined, and the importance of in vitro experimental models for establishing the relationship between receptor binding and the cellular response is emphasized.
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Affiliation(s)
- K E Mogensen
- Laboratoire d'Oncologie Virale, CNRS ER 274, Villejuif, France
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Smith KR, Borchardt RT. Permeability and mechanism of albumin, cationized albumin, and glycosylated albumin transcellular transport across monolayers of cultured bovine brain capillary endothelial cells. Pharm Res 1989; 6:466-73. [PMID: 2762222 DOI: 10.1023/a:1015960205409] [Citation(s) in RCA: 60] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
We have measured the permeability and binding characteristics of bovine serum albumin (BSA), cationized BSA (cBSA), and glycosylated BSA (gBSA) to primary cultures of bovine brain capillary endothelial cells (BBCEC). These endothelial cells serve as an in vitro model to study the binding, uptake, and transcellular transport of small and large molecule flux across the blood-brain barrier. The rate of [3H]BSA flux across the cultured BBCEC monolayers grown onto polycarbonate membranes (5-microns pore size) was linear with increasing BSA concentration and the flux could be inhibited by temperature reduction to 0-4 degrees C. The maximal binding of [3H]BSA was 0.04 fmol/mg total cell protein and could not be inhibited by nonradiolabeled BSA. The binding of cBSA and gBSA was rapid and could be inhibited by nonradiolabeled cBSA or gBSA, respectively. The maximal amount bound was 1.8 fmol/mg total cell protein for cBSA and 17.4 fmol/mg total cell protein for gBSA. The dissociation constants (Kd's) were 27 +/- 13 and 3.7 +/- 1.1 nM for cBSA and gBSA, respectively. The flux rates of cBSA and gBSA across the endothelial cell monolayers were linear with respect to concentration and they were approximately seven times greater than those observed for BSA. Each of the proteins appeared on the antiluminal side of the endothelial cell monolayers primarily (90%) as intact protein as determined by trichloroacetic acid (TCA) precipitations and sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis (PAGE). The results for BSA are similar to those observed for lucifer yellow, a fluid-phase endocytic marker.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- K R Smith
- Department of Pharmaceutical Chemistry, School of Pharmacy, University of Kansas, Lawrence 66045
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Catapano AL. The low density lipoprotein receptor: structure, function and pharmacological modulation. Pharmacol Ther 1989; 43:187-219. [PMID: 2675133 DOI: 10.1016/0163-7258(89)90118-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Affiliation(s)
- A L Catapano
- Institute of Pharmacological Sciences, Milano, Italy
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Yokota T, Arai N, de Vries J, Spits H, Banchereau J, Zlotnik A, Rennick D, Howard M, Takebe Y, Miyatake S. Molecular biology of interleukin 4 and interleukin 5 genes and biology of their products that stimulate B cells, T cells and hemopoietic cells. Immunol Rev 1988; 102:137-87. [PMID: 3284813 DOI: 10.1111/j.1600-065x.1988.tb00744.x] [Citation(s) in RCA: 141] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- T Yokota
- Department of Molecular Biology, DNAX Research Institute of Molecular and Cellular Biology, Palo Alto, California
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Yonezawa K, Yokono K, Shii K, Hari J, Yaso S, Amano K, Sakamoto T, Kawase Y, Akiyama H, Nagata M. Insulin-degrading enzyme is capable of degrading receptor-bound insulin. Biochem Biophys Res Commun 1988; 150:605-14. [PMID: 3277630 DOI: 10.1016/0006-291x(88)90436-6] [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: 01/05/2023]
Abstract
In the investigation of the intracellular sites of insulin degradation, it might be important whether receptor-bound insulin could be a substrate for insulin-degrading enzyme (IDE). Insulin receptor and IDE were purified from rat liver using a wheat germ agglutinin column and monoclonal anti-IDE antibody affinity column, respectively. [125I]insulin-receptor complex was incubated with various amounts of IDE at 0 degree C in the presence of disuccinimidyl suberate and analyzed by reduced 7.5% SDS-PAGE and autoradiography. With increasing amounts of IDE, the radioactivity of 135 kd band (insulin receptor alpha-subunit) decreased, whereas that of 110 kd band (IDE) appeared then gradually increased, suggesting that IDE could bind to receptor-bound insulin. During incubation of insulin-receptor complex with IDE at 37 degrees C, about half of the [125I]insulin was dissociated from the complex. However, the time course of [125I]insulin degradation in this incubation was essentially identical to that of free [125I]insulin degradation. Cross-linked, non-dissociable receptor-bound [125I]insulin was also degraded by IDE. Rebinding studies to IM-9 cells showed that the receptor binding activity of dissociated [125I]insulin from insulin-receptor complex incubated with IDE was significantly (p less than 0.001) decreased as compared with that without the enzyme. These results, therefore, show that IDE could recognize and degrade receptor-bound insulin, and suggest that IDE may be involved in insulin metabolism during receptor-mediated endocytosis through the degradation of receptor-bound insulin in early neutral vesicles before their internal pH is acidified.
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Affiliation(s)
- K Yonezawa
- Second Department of Internal Medicine, Kobe University School of Medicine, Japan
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McCrae C, Maxwell L, Ceredig R. Intracellular pathway of interleukin-2 receptors studied using immunogold electron microscopy. Immunol Cell Biol 1988; 66 ( Pt 3):185-91. [PMID: 3155341 DOI: 10.1038/icb.1988.23] [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: 01/04/2023]
Abstract
The fate of internalized interleukin-2 receptors (IL-2R) on proliferating T cell blasts and Lyt-2-/L3T4- thymocytes was studied by immunogold electron microscopy. Immediately following labeling, IL-2R were found in coated pits and with time there was sequential appearance of gold particles in smooth vesicles or endosomes, multivesicular bodies and lysosomes. Thus the IL-2R appears to be a member of cell surface receptors internalized by endocytosis via coated pits.
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Affiliation(s)
- C McCrae
- Department of Experimental Pathology, John Curtin School of Medical Research, Canberra, Australia
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Binding, internalization, and intracellular processing of protein ligands. Derivation of rate constants by computer modeling. J Biol Chem 1987. [DOI: 10.1016/s0021-9258(18)48269-5] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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