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Lin SX, Mallet WG, Huang AY, Maxfield FR. Endocytosed cation-independent mannose 6-phosphate receptor traffics via the endocytic recycling compartment en route to the trans-Golgi network and a subpopulation of late endosomes. Mol Biol Cell 2003; 15:721-33. [PMID: 14595110 PMCID: PMC329388 DOI: 10.1091/mbc.e03-07-0497] [Citation(s) in RCA: 86] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Although the distribution of the cation-independent mannose 6-phosphate receptor (CI-MPR) has been well studied, its intracellular itinerary and trafficking kinetics remain uncertain. In this report, we describe the endocytic trafficking and steady-state localization of a chimeric form of the CI-MPR containing the ecto-domain of the bovine CI-MPR and the murine transmembrane and cytoplasmic domains expressed in a CHO cell line. Detailed confocal microscopy analysis revealed that internalized chimeric CI-MPR overlaps almost completely with the endogenous CI-MPR but only partially with individual markers for the trans-Golgi network or other endosomal compartments. After endocytosis, the chimeric receptor first enters sorting endosomes, and it then accumulates in the endocytic recycling compartment. A large fraction of the receptors return to the plasma membrane, but some are delivered to the trans-Golgi network and/or late endosomes. Over the course of an hour, the endocytosed receptors achieve their steady-state distribution. Importantly, the receptor does not start to colocalize with late endosomal markers until after it has passed through the endocytic recycling compartment. In CHO cells, only a small fraction of the receptor is ever detected in endosomes bearing substrates destined for lysosomes (kinetically defined late endosomes). These data demonstrate that CI-MPR takes a complex route that involves multiple sorting steps in both early and late endosomes.
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Affiliation(s)
- Sharron X Lin
- Department of Biochemistry, Weill Medical College of Cornell University, New York, New York 10021, USA
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2
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Hirst CE, Buzza MS, Bird CH, Warren HS, Cameron PU, Zhang M, Ashton-Rickardt PG, Bird PI. The intracellular granzyme B inhibitor, proteinase inhibitor 9, is up-regulated during accessory cell maturation and effector cell degranulation, and its overexpression enhances CTL potency. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2003; 170:805-15. [PMID: 12517944 DOI: 10.4049/jimmunol.170.2.805] [Citation(s) in RCA: 123] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Granzyme B (grB) is a serine proteinase released by cytotoxic lymphocytes (CLs) to kill abnormal cells. GrB-mediated apoptotic pathways are conserved in nucleated cells; hence, CLs require mechanisms to protect against ectopic or misdirected grB. The nucleocytoplasmic serpin, proteinase inhibitor 9 (PI-9), is a potent inhibitor of grB that protects cells from grB-mediated apoptosis in model systems. Here we show that PI-9 is present in CD4(+) cells, CD8(+) T cells, NK cells, and at lower levels in B cells and myeloid cells. PI-9 is up-regulated in response to grB production and degranulation, and associates with grB-containing granules in activated CTLs and NK cells. Intracellular complexes of PI-9 and grB are evident in NK cells, and overexpression of PI-9 enhances CTL potency, suggesting that cytoplasmic grB, which may threaten CL viability, is rapidly inactivated by PI-9. Because dendritic cells (DCs) acquire characteristics similar to those of target cells to activate naive CD8(+) T cells and therefore may also require protection against grB, we investigated the expression of PI-9 in DCs. PI-9 is evident in thymic DCs (CD3(-), CD4(+), CD8(-), CD45(+)), tonsillar DCs, and DC subsets purified from peripheral blood (CD16(+) monocytes and CD123(+) plasmacytoid DCs). Furthermore, PI-9 is expressed in monocyte-derived DCs and is up-regulated upon TNF-alpha-induced maturation of monocyte-derived DCs. In conclusion, the presence and subcellular localization of PI-9 in leukocytes and DCs are consistent with a protective role against ectopic or misdirected grB during an immune response.
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Affiliation(s)
- Claire E Hirst
- Department of Biochemistry and Molecular Biology, Monash University, Clayton, Australia
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3
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Hindmarsh EJ, Staykova MA, Willenborg DO, Parish CR. Cell surface expression of the 300 kDa mannose-6-phosphate receptor by activated T lymphocytes. Immunol Cell Biol 2001; 79:436-43. [PMID: 11564151 DOI: 10.1046/j.1440-1711.2001.01026.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Phosphosugars, such as mannose-6-phosphate (M6P), have been shown previously to display anti-inflammatory properties, notably inhibition of experimental autoimmune encephalomyelitis (EAE) and adjuvant-induced arthritis in rats. It has been proposed that M6P exerts its anti-inflammatory effect by displacing lysosomal enzymes, which are involved in T-cell extravasation into inflammatory sites, from the 300 kDa mannose-6- phosphate receptor (MPR-300) on the surface of T cells. If this model is correct MPR-300 should be selectively expressed on the surface of activated T cells, as T cell entry into the central nervous system in EAE depends on the T cells being in an activated state. Thus, the present study examines whether cell surface expression of MPR-300 by T lymphocytes correlates with their state of activation and whether T cells in inflammatory sites express the receptor. Flow cytometric studies showed MPR-300 to be absent from the surface of unstimulated rat T cells isolated from peripheral blood and lymphoid tissues, and T cells resident within the peritoneal cavity. In contrast, MPR-300 was expressed on activated T cells derived from an inflammatory peritoneal exudate. In vitro studies demonstrated transient expression of MPR-300 on the surface of splenic T cells following stimulation with Con A. MPR-300 was also induced on T-cell lines by antigen stimulation. These data demonstrate that T cells in inflammatory sites express MPR-300 on their surface and activation of T lymphocytes induces cell surface expression of MPR-300. Such findings are consistent with the hypothesis that cell surface MPR-300 is required for the entry of T cells into inflammatory sites.
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Affiliation(s)
- E J Hindmarsh
- Division of Immunology and Cell Biology, John Curtin School of Medical Research, Australian National University, Canberra, Australian Capital Territory, Australia
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4
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Mallet WG, Maxfield FR. Chimeric forms of furin and TGN38 are transported with the plasma membrane in the trans-Golgi network via distinct endosomal pathways. J Cell Biol 1999; 146:345-59. [PMID: 10465644 PMCID: PMC2156176 DOI: 10.1083/jcb.146.2.345] [Citation(s) in RCA: 178] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/1999] [Accepted: 06/18/1999] [Indexed: 11/22/2022] Open
Abstract
Furin and TGN38 are menbrane proteins that cycle between the plasma membrane and the trans-Golgi network (TGN), each maintaining a predominant distribution in the TGN. We have used chimeric proteins with an extracellular Tac domain and the cytoplasmic domain of TGN38 or furin to study the trafficking of these proteins in endosomes. Previously, we demonstrated that the postendocytic trafficking of Tac-TGN38 to the TGN is via the endocytic recycling pathway (Ghosh, R.N.,W.G. Mallet,T.T. Soe,T.E.McGraw, and F.R. Maxfield.1998.J. Cell Biol.142:923-936). Here we show that internalized Tac-furin is delivered to the TGN through late endosomes, bypassing the endocytic recycling compartment. The transport of Tac-furin from late endosomes to the TGN appears to proceed via an efficient, single-pass mechanism. Delivery of Tac-furin but not Tac-TGN38 to the TGN is blocked by nocodazole, and the two pathways are also differentially affected by wortmannin. These studies demonstrate the existence of two independentpathways for endosomal transport of proteins to the TGN from the plasma membrane.
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Affiliation(s)
- William G. Mallet
- Department of Biochemistry, Weill Medical College of Cornell University, New York, New York 10021
| | - Frederick R. Maxfield
- Department of Biochemistry, Weill Medical College of Cornell University, New York, New York 10021
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5
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van Weert AW, Dunn KW, Geuze HJ, Maxfield FR, Stoorvogel W. Transport from late endosomes to lysosomes, but not sorting of integral membrane proteins in endosomes, depends on the vacuolar proton pump. J Cell Biol 1995; 130:821-34. [PMID: 7642700 PMCID: PMC2199957 DOI: 10.1083/jcb.130.4.821] [Citation(s) in RCA: 274] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Endocytosed proteins are sorted in early endosomes to be recycled to the plasma membrane or transported further into the degradative pathway. We studied the role of endosomes acidification on the endocytic trafficking of the transferrin receptor (TfR) as a representative for the recycling pathway, the cation-dependent mannose 6-phosphate receptor (MPR) as a prototype for transport to late endosomes, and fluid-phase endocytosed HRP as a marker for transport to lysosomes. Toward this purpose, bafilomycin A1 (Baf), a specific inhibitor of the vacuolar proton pump, was used to inhibit acidification of the vacuolar system. Microspectrofluorometric measurement of the pH of fluorescein-rhodamine-conjugated transferrin (Tf)-containing endocytic compartments in living cells revealed elevated endosomal pH values (pH > 7.0) within 2 min after addition of Baf. Although recycling of endocytosed Tf to the plasma membrane continued in the presence of Baf, recycled Tf did not dissociate from its receptor, indicating failure of Fe3+ release due to a neutral endosomal pH. In the presence of Baf, the rates of internalization and recycling of Tf were reduced by a factor of 1.40 +/- 0.08 and 1.57 +/- 0.25, respectively. Consequently, little if any in TfR expression at the cell surface was measured during Baf treatment. Sorting between endocytosed TfR and MPR was analyzed by the HRP-catalyzed 3,3'-diaminobenzidine cross-linking technique, using transferrin conjugated to HRP to label the endocytic pathway of the TfR. In the absence of Baf, endocytosed surface 125I-labeled MPR was sorted from the TfR pathway starting at 10 min after uptake, reaching a plateau of 40% after 45 min. In the presence of Baf, sorting was initiated after 20 min of uptake, reaching approximately 40% after 60 min. Transport of fluid-phase endocytosed HRP to late endosomes and lysosomes was measured using cell fractionation and immunogold electron microscopy. Baf did not interfere with transport of HRP to MPR-labeled late endosomes, but nearly completely abrogated transport to cathepsin D-labeled lysosomes. From these results, we conclude that trafficking through early and late endosomes, but not to lysosomes, continued upon inactivation of the vacuolar proton pump.
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Affiliation(s)
- A W van Weert
- Universiteit Utrecht, Faculty of Medicine, Department of Cell Biology, The Netherlands
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6
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Erickson P, Herzberg M. Evidence for the covalent linkage of carbohydrate polymers to a glycoprotein from Streptococcus sanguis. J Biol Chem 1993. [DOI: 10.1016/s0021-9258(20)80451-7] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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7
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Ludwig T, Griffiths G, Hoflack B. Distribution of newly synthesized lysosomal enzymes in the endocytic pathway of normal rat kidney cells. J Cell Biol 1991; 115:1561-72. [PMID: 1661730 PMCID: PMC2289208 DOI: 10.1083/jcb.115.6.1561] [Citation(s) in RCA: 124] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
We have investigated the distribution of newly synthesized lysosomal enzymes in endocytic compartments of normal rat kidney (NRK) cells. The mannose-6-phosphate (Man6-P) containing lysosomal enzymes could be iodinated in situ after internalization of lactoperoxidase (LPO) by fluid phase endocytosis and isolated on CI-MPR affinity columns. For EM studies, the ectodomain of the CI-MPR conjugated to colloidal gold was used as a probe specific for the phosphomannosyl marker of the newly synthesized hydrolases. In NRK cells, approximately 20-40% of the phosphorylated hydrolases present in the entire pathway were found in early endocytic structures proximal to the 18 degrees C temperature block including early endosomes. These structures were characterized by a low content of endogenous CI-MPR and were accessible to fluid phase markers internalized for 5-15 min at 37 degrees C. The bulk of the phosphorylated lysosomal enzymes was found in late endocytic structures distal to the 18 degrees C block, rich in endogenous CI-MPR and accessible to endocytic markers internalized for 30-60 min at 37 degrees C. The CI-MPR negative lysosomes were devoid of phosphorylated hydrolases. This distribution was unchanged in cells treated with Man6-P to block recapture of secreted lysosomal enzymes. However, lysosomal enzymes were no longer detected in the early endosomal elements of cells treated with cycloheximide. Immunoprecipitation of cathepsin D from early endosomes of pulse-labeled cells showed that this hydrolase is a transient component of this compartment. These data indicate that in NRK cells, the earliest point of convergence of the lysosomal biosynthetic and the endocytic pathways is the early endosome.
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Affiliation(s)
- T Ludwig
- European Molecular Biology Laboratory, Cell Biology Programme, Heidelberg, Germany
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8
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Cloning, sequencing, and expression of a cDNA encoding rat LIMP II, a novel 74-kDa lysosomal membrane protein related to the surface adhesion protein CD36. J Biol Chem 1991. [DOI: 10.1016/s0021-9258(18)55375-8] [Citation(s) in RCA: 107] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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9
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Park JE, Lopez JM, Cluett EB, Brown WJ. Identification of a membrane glycoprotein found primarily in the prelysosomal endosome compartment. J Cell Biol 1991; 112:245-55. [PMID: 1846371 PMCID: PMC2288819 DOI: 10.1083/jcb.112.2.245] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Cells contain an intracellular compartment that serves as both the "prelysosomal" delivery site for newly synthesized lysosomal enzymes by the mannose 6-phosphate (Man6P) receptor and as a station along the endocytic pathway to lysosomes. We have obtained mAbs to a approximately 57-kD membrane glycoprotein, (called here plgp57), found predominantly in this prelysosomal endosome compartment. This conclusion is supported by the following results: (a) plgp57 was primarily found in a population of late endosomes that were located just distal to the 20 degrees C block site in the endocytic pathway to lysosomes (approximately 83% of the prelysosomes were positive for plgp57 but less than 5% of the early endosomes had detectable amounts of this marker); (b) plgp57 and the cation-independent (CI) Man6P receptor were located in many of the same intracellular vesicles; (c) plgp57 was found in the membranes of an acidic compartment; (d) immunoelectron microscopy showed that plgp57 was located in characteristic multilamellar- and multivesicular-type vacuoles believed to be prelysosomal endosomes; and (e) cell fractionation studies demonstrated that plgp57 was predominantly found in low density organelles which comigrated with late endosomes and CI Man6P receptors, and only approximately 10-15% of the antigen was found in high density fractions containing the majority of secondary lysosomes. These results indicate that plgp57 is a novel marker for a unique prelysosomal endosome compartment that is the site of confluence of the endocytic and biosynthetic pathways to lysosomes.
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Affiliation(s)
- J E Park
- Section of Biochemistry, Molecular and Cell Biology, Cornell University, Ithaca, New York 14853
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10
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Dietel M. Morphological characterization of cell receptors. CURRENT TOPICS IN PATHOLOGY. ERGEBNISSE DER PATHOLOGIE 1991; 83:71-116. [PMID: 1848809 DOI: 10.1007/978-3-642-75515-6_4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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11
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Geuze HJ, Morré DJ. Trans-Golgi reticulum. JOURNAL OF ELECTRON MICROSCOPY TECHNIQUE 1991; 17:24-34. [PMID: 1993936 DOI: 10.1002/jemt.1060170105] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The trans-Golgi apparatus reticulum is that portion of the Golgi apparatus located in the trans-most aspect of the stack exhibiting certain characteristic morphological and functional characteristics. The membranes of the trans-Golgi reticulum are reticular in form, thickened with plasma membrane-like characteristics and with a considerable portion of their surface covered by clathrin coats. The enzymes thiamine pyrophosphatase and sialyl- and galactosyl transferases are functional markers. Correlative studies show the trans-Golgi apparatus reticulum to be involved in glycoprotein, enzyme and receptor processing and sorting along multiple pathways. Sorting and transfer of constituents to lysosomes, to secretory granules, or to the plasma membrane emerge as dominant functions.
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Affiliation(s)
- H J Geuze
- Department of Cell Biology, Medical School, University of Utrecht, The Netherlands
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12
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The insulin-like growth factor II/mannose-6-phosphate receptor : IGF-II/Man-6-P receptor. Cytotechnology 1989; 2:287-305. [PMID: 22358870 DOI: 10.1007/bf00364994] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
Abstract
Recent evidence from molecular cloning, biochemical and immunological experiments has established that the cation-independent mannose-6-phosphate (Man-6-P) receptor and insulin-like growth factor-II (IGF-II) receptor are the same protein. Although the role of the IGF-II/Man-6-P receptor as a transporter of hydrolytic enzymes in the biogenesis of lysosomes is certain, elucidation of the receptor's structure has not yet provided major insights into the function of IGF-II binding. Mutually exclusive binding of IGF-II and naturally occurring phosphomannosyl ligands to distinct but proximal sites on the receptor suggests that the IGF-II/Man-6-P receptor cannot simultaneously fulfill the functional requirements of both IGF-II and lysosomal enzymes. Does the receptor transduce on intracellular signal in order to mediate the biological effects of IGF-II? If so, then the receptor must interact with an effector molecule, perhaps a G protein, in the mechanism of IGF-II action. Further information from ligand binding and especially mutagenesis experiments will be needed to elucidate the potentially multiple functions of the IGF-II/Man-6-P receptor.
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13
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Stoorvogel W, Geuze HJ, Griffith JM, Schwartz AL, Strous GJ. Relations between the intracellular pathways of the receptors for transferrin, asialoglycoprotein, and mannose 6-phosphate in human hepatoma cells. J Cell Biol 1989; 108:2137-48. [PMID: 2544602 PMCID: PMC2115624 DOI: 10.1083/jcb.108.6.2137] [Citation(s) in RCA: 101] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
We compared the intracellular pathways of the transferrin receptor (TfR) with those of the asialoglycoprotein receptor (ASGPR) and the cation-independent mannose 6-phosphate receptor (MPR)/insulin-like growth factor II receptor during endocytosis in Hep G2 cells. Cells were allowed to endocytose a conjugate of horseradish peroxidase and transferrin (Tf/HRP) via the TfR system. Postnuclear supernatants of homogenized cells were incubated with 3,3'-diaminobenzidine (DAB) and H2O2. Peroxidase-catalyzed oxidation of DAB within Tf/HRP-containing endosomes cross-linked their contents to DAB polymer. The cross-linking efficiency was dependent on the intravesicular Tf/HRP concentration. The loss of detectable receptors from samples of cell homogenates treated with DAB/H2O2 was used as a measure of colocalization with Tf/HRP. To compare the distribution of internalized plasma membrane receptors with Tf/HRP, cells were first surface-labeled with 125I at 0 degrees C. After uptake of surface 125I-labeled receptors at 37 degrees C in the presence of Tf/HRP, proteinase K was used at 0 degrees C to remove receptors remaining at the plasma membrane. Endocytosed receptors were isolated by means of immunoprecipitation. 125I-TfR and 125I-ASGPR were not sorted from endocytosed Tf/HRP. 125I-MPR initially also resided in Tf/HRP-containing compartments, however 70% was sorted from the Tf/HRP pathway between 20 and 45 min after uptake. To study the accessibility of total intracellular receptor pools to endocytosed Tf/HRP, nonlabeled cells were used, and the receptors were detected by means of Western blotting. The entire intracellular TfR population, but only 70 and 50% of ASGPR and MPR, respectively, were accessible to endocytosed Tf/HRP. These steady-state levels were reached by 10 min of continuous Tf/HRP uptake at 37 degrees C. We conclude that 30% of the intracellular ASGPR pool is not involved in endocytosis (i.e., is silent). Double-labeling immunoelectron microscopy on DAB-labeled cells showed a considerable pool of ASGPR in secretory albumin-positive, Tf/HRP-negative, trans-Golgi reticulum. We suggest that this pool represents the silent ASGPR that has been biochemically determined. A model of receptor transport routes is presented and discussed.
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Affiliation(s)
- W Stoorvogel
- Laboratory of Cell Biology, University of Utrecht Medical School, The Netherlands
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14
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Messner DJ, Griffiths G, Kornfeld S. Isolation and characterization of membranes from bovine liver which are highly enriched in mannose 6-phosphate receptors. J Cell Biol 1989; 108:2149-62. [PMID: 2544603 PMCID: PMC2115605 DOI: 10.1083/jcb.108.6.2149] [Citation(s) in RCA: 32] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
We have developed a method for the isolation of the subcellular organelles from bovine liver which are enriched in the cation-independent mannose 6-phosphate receptor (CI-MPR) and the cation-dependent mannose 6-phosphate receptor (CD-MPR). The purification scheme consists of sedimentation of a postnuclear supernatant fraction on a sucrose gradient followed by immunoisolation using specific anti-peptide antibodies conjugated to magnetic polystyrene beads. Antibodies that recognize the cytoplasmic domain of either the CI-MPR or the CD-MPR routinely give membrane preparations that are approximately 50-fold enriched in each of the respective receptors, as determined by quantitative Western blotting. The immunoisolated membranes are also enriched in the other MPR, as well as in the asialoglycoprotein receptor. They contain significantly lower levels of enzyme activities representative of the plasma membrane (5' nucleotidase) or the Golgi complex (galactosyltransferase and sialyltransferase). There is little or no enrichment for either the lysosomal enzymes beta-hexosaminidase and tartrate-resistant acid phosphatase, or the mitochondrial enzyme succinate-tetrazolium reductase. These data, together with electron microscopy of the immunoisolated material, suggest that the bulk of MPR-containing membranes we have isolated from bovine liver correspond to endosomes. Analysis by SDS-PAGE indicates that several proteins, including two with apparent molecular weights of 170 K and 400 K, are significantly enriched in the purified fractions and may represent potential markers for MPR-containing endosomes.
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Affiliation(s)
- D J Messner
- Department of Biological Chemistry, Washington University School of Medicine, St. Louis, Missouri 63110
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15
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Transport of surface mannose 6-phosphate receptor to the Golgi complex in cultured human cells. J Biol Chem 1989. [DOI: 10.1016/s0021-9258(18)83287-2] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
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16
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Brown WJ, Farquhar MG. Immunoperoxidase methods for the localization of antigens in cultured cells and tissue sections by electron microscopy. Methods Cell Biol 1989; 31:553-69. [PMID: 2674632 DOI: 10.1016/s0091-679x(08)61626-x] [Citation(s) in RCA: 83] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
We have presented our detailed methods for localizing antigens in cultured cells and tissue sections by IP at the EM level. Immunoperoxidase cytochemistry is particularly well suited for the study of sparse antigens as a result of the enzymatic amplification afforded by the method, and of molecules confined within a membrane-enclosed compartment wherein the DAB reaction produce can accumulate. Although IP is commonly used to localize membrane-compartmentalized molecules, reliable qualitative information can also be obtained on cytoplasmic antigens as well (Anderson et al., 1978; Merisko et al., 1986; Rodman et al., 1984). For these and other reasons, it is likely that IP cytochemistry will continue to be an important tool for the cell biologist especially in the study of membrane traffic. Other inventive combinations of immunocytochemical methods will likely be forthcoming, for example, combining IP localization with postembedding labeling by colloidal-gold conjugates to provide triple EM labeling.
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Affiliation(s)
- W J Brown
- Section of Biochemistry, Molecular, and Cell Biology, Cornell University, Ithaca, New York 14853
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17
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Baron R, Neff L, Brown W, Courtoy PJ, Louvard D, Farquhar MG. Polarized secretion of lysosomal enzymes: co-distribution of cation-independent mannose-6-phosphate receptors and lysosomal enzymes along the osteoclast exocytic pathway. J Cell Biol 1988; 106:1863-72. [PMID: 2968345 PMCID: PMC2115156 DOI: 10.1083/jcb.106.6.1863] [Citation(s) in RCA: 172] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
The osteoclast is a polarized cell which secretes large amounts of newly synthesized lysosomal enzymes into an apical extracellular lacuna where bone resorption takes place. Using immunocytochemical techniques, we have localized the cation-independent mannose-6-phosphate (Man6P) receptor and lysosomal enzymes in this cell type in order to determine the expression and distribution of this receptor and its ligands. The results demonstrate that the osteoclast expresses large amounts of immunoreactive cation-independent Man6P receptors, despite the fact that most of the lysosomal enzymes it synthesizes are secreted. The lysosomal enzymes and the receptors are co-distributed along the exocytic pathway, i.e., the endoplasmic reticulum, including the perinuclear envelope, the Golgi stacks as well as numerous small transport vesicles that appear to fuse with the ruffled border membrane. Within the Golgi complex, the receptors and lysosomal enzymes were found distributed in two predominant patterns; (a) in all the cisternae, from cis to trans, or (b) predominantly in cis- and trans-Golgi cisternae, with the middle Golgi cisternae being unstained or depleted in antigen. This pattern suggests that enzymes and receptors traverse the Golgi from cis to trans and preferentially accumulate in cis- and in trans-cisternae. This study therefore suggests that, in the osteoclast, Man6P receptors are involved in the vectorial transport and targeting of newly synthesized lysosomal enzymes, presumably via a constitutive pathway, to the apical membrane where they are secreted into the bone-resorbing compartment. This mechanism could insure polarized secretion of lysosomal enzymes into the bone-resorbing lacuna.
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Affiliation(s)
- R Baron
- Department of Cell Biology, Yale University School of Medicine, New Haven, Connecticut 06510
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18
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MacDonald RG, Pfeffer SR, Coussens L, Tepper MA, Brocklebank CM, Mole JE, Anderson JK, Chen E, Czech MP, Ullrich A. A single receptor binds both insulin-like growth factor II and mannose-6-phosphate. Science 1988; 239:1134-7. [PMID: 2964083 DOI: 10.1126/science.2964083] [Citation(s) in RCA: 288] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Amino acid sequences deduced from rat complementary DNA clones encoding the insulin-like growth factor II (IGF-II) receptor closely resemble those of the bovine cation-independent mannose-6-phosphate receptor (Man-6-P receptorCI), suggesting they are identical structures. It is also shown that IGF-II receptors are adsorbed by immobilized pentamannosyl-6-phosphate and are specifically eluted with Man-6-P. Furthermore, Man-6-P specifically increases by about two times the apparent affinity of the purified rat placental receptor for 125I-labeled IGF-II. These results indicate that the type II IGF receptor contains cooperative, high-affinity binding sites for both IGF-II and Man-6-P-containing proteins.
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Affiliation(s)
- R G MacDonald
- Department of Biochemistry, University of Massachusetts Medical Center, Worcester 01655
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19
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Duncan JR, Kornfeld S. Intracellular movement of two mannose 6-phosphate receptors: return to the Golgi apparatus. J Cell Biol 1988; 106:617-28. [PMID: 2964450 PMCID: PMC2115106 DOI: 10.1083/jcb.106.3.617] [Citation(s) in RCA: 226] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
We have used Chinese hamster ovary (CHO) cells and a murine lymphoma cell line to study the recycling of the 215-kD and the 46-kD mannose 6-phosphate receptors to various regions of the Golgi to determine the site where the receptors first encounter newly synthesized lysosomal enzymes. For assessing return to the trans-most Golgi compartments containing sialyltransferase (trans-cisternae and trans-Golgi network), the oligosaccharides of receptor molecules on the cell surface were labeled with [3H]galactose at 4 degrees C. Upon warming to 37 degrees C, the [3H]galactose residues on both receptors were substituted with sialic acid with a t1/2 approximately 3 hrs. Other glycoproteins acquired sialic acid at least 8-10 times slower. Return of the receptors to the trans-Golgi cisternae containing galactosyltransferase could not be detected. Return to the cis/middle Golgi cisternae containing alpha-mannosidase I was measured by adding deoxymannojirimycin, a mannosidase I inhibitor, during the initial posttranslational passage of [3H]mannose-labeled glycoproteins through the Golgi, thereby preserving oligosaccharides which would be substrates for alpha-mannosidase I. After removal of the inhibitor, return to the early Golgi with subsequent passage through the Golgi complex was measured by determining the conversion of the oligosaccharides from high mannose to complex-type units. This conversion was very slow for the receptors and other glycoproteins (t1/2 approximately 20 h). Exposure of the receptors and other glycoproteins to the dMM-sensitive alpha-mannosidase without movement through the Golgi apparatus was determined by measuring the loss of mannose residues from these proteins. This loss was also slow. These results indicate that both Man-6-P receptors routinely return to the Golgi compartment which contains sialyltransferase and recycle through other regions of the Golgi region less frequently. We infer that the trans-Golgi network is the major site for lysosomal enzyme sorting in CHO and murine lymphoma cells.
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Affiliation(s)
- J R Duncan
- Department of Internal Medicine, Washington University School of Medicine, St. Louis, Missouri 63110
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20
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Storrie B. Assembly of lysosomes: perspectives from comparative molecular cell biology. INTERNATIONAL REVIEW OF CYTOLOGY 1988; 111:53-105. [PMID: 3074962 DOI: 10.1016/s0074-7696(08)61731-3] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Affiliation(s)
- B Storrie
- Department of Biochemistry and Nutrition, Virginia Polytechnic Institute and State University, Blacksburg 24061
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21
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Chicheportiche Y, Tartakoff AM. The use of antibodies for analysis of the secretory and endocytic paths of eukaryotic cells. Subcell Biochem 1988; 12:243-75. [PMID: 3043768 DOI: 10.1007/978-1-4899-1681-5_7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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22
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Grossman A. Information transfer in biological systems: targeting of proteins to specific organelles or to the extracellular environment (secretion). COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY. B, COMPARATIVE BIOCHEMISTRY 1988; 91:389-424. [PMID: 3069302 DOI: 10.1016/0305-0491(88)90001-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Orderliness is the salient characteristic of living systems. Cells are intolerant of disorder. They express this by rapidly eliminating or degrading out-of-place molecules. When cells are broken apart and their constituent organelles separated and analysed, the same types of macromolecules are always associated with the same subcellular structures. One finds, for example, the same proteins in mitochondria time after time, and these differ from the sets of proteins found in nuclei, secretory granules, or plasma membranes. The information necessary to target each protein to its appropriate intracellular destination is determined primarily by the gene for that protein. Encoded within the DNA structure of genes are signals that specify where each protein molecule belongs. Thus, it is the transfer of information from one macromolecule to another that maintains the integrity and orderliness of living cells.
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Affiliation(s)
- A Grossman
- Department of Pharmacology, New York University Medical Center, NY 10016
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23
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Brown WJ, Farquhar MG. The distribution of 215-kilodalton mannose 6-phosphate receptors within cis (heavy) and trans (light) Golgi subfractions varies in different cell types. Proc Natl Acad Sci U S A 1987; 84:9001-5. [PMID: 2962195 PMCID: PMC299679 DOI: 10.1073/pnas.84.24.9001] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
The distribution of mannose 6-phosphate (Man-6-P) receptors for lysosomal enzymes was investigated in Golgi subfractions prepared from three different cultured cell lines. Total microsomal fractions from clone 9 hepatocytes, normal rat kidney, or Chinese hamster ovary cells were subfractionated by flotation in sucrose density gradients, which resolves Golgi membranes into heavy (cis), intermediate, and light (trans) subfractions. The distribution of Man-6-P receptors within the subfractions was assessed by quantitative immunoprecipitation, and the results were compared to those obtained by immunoperoxidase localization of the receptors in Golgi cisternae of intact cells. In all cases, the results obtained by Golgi subfractionation and by immunoelectron microscopy were in agreement. In clone 9 cells, Man-6-P receptors were enriched in heavy (cis) Golgi subfractions, whose peak density (rho = 1.17) was greater than those containing either galactosyltransferase activity, a trans Golgi marker, or alpha-mannosidase II, a middle Golgi marker. By immunoelectron microscopy, the receptors were localized to a single cis Golgi cisterna. In Chinese hamster ovary cells, Man-6-P receptors were concentrated in Golgi membranes of low density (1.12 g/ml) overlapping the peak of galactosyltransferase activity. By the immunoperoxidase technique, the receptors were usually localized to a single trans Golgi cisterna. In normal rat kidney cells, Man-6-P receptors were found to be broadly distributed across Golgi membranes (rho = 1.12-1.17), and by immunoperoxidase localization they were found to be broadly distributed across the stacked Golgi cisternae. It is concluded that the distribution of Man-6-P receptors within the Golgi complex varies from one cell type to another. These differences in receptor distribution may reflect variations in lysosomal enzyme trafficking among different cell types.
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Affiliation(s)
- W J Brown
- Section of Biochemistry, Molecular and Cell Biology, Cornell University, Ithaca, NY 14853
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24
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Gonatas JO, Gonatas NK, Stieber A, Louvard D. Polypeptides of the Golgi apparatus of neurons from rat brain. J Neurochem 1987; 49:1498-506. [PMID: 3668536 DOI: 10.1111/j.1471-4159.1987.tb01020.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
An antiserum was raised against fractions of the Golgi apparatus of neurons from rat brain. Immunoblots of these fractions with the antiserum showed two principal bands of 185 and 150 kilodaltons (kd) in apparent molecular mass. The antiserum reacted with five or six bands of 200, 150, 130, 100-110, 64, and 40 kd in apparent molecular mass in immunoblots of several crude brain membrane fractions. Affinity-purified antibodies from the different gel bands transferred to nitrocellulose paper were used in immunoblot and immunocytochemical studies. Antibodies eluted from the 200-, 150-, 100-110-, and 64-kd bands reacted not only with the corresponding band but also with the other three bands. Antibodies eluted from the 40-kd band stained only the corresponding band. On light and/or electron microscopic immunocytochemistry, the antiserum stained the Golgi apparatus of rat neurons, glia, liver, and kidney tubule cells. Weaker, segmented, and less consistent staining was observed in nuclear envelopes, rough endoplasmic reticulum, and plasma membranes of neurons. Antibodies eluted from the bands at 200, 150, 100-110, and 64 kd stained intermediate cisterns of the Golgi apparatus of neurons. These findings suggest that a group of related polypeptides of brain membranes is preferentially expressed or enriched in the Golgi apparatus of neurons. Polypeptides with apparent molecular masses of 185 and 150 kd probably represent moieties endogenous to membranes of the neuronal Golgi apparatus.
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Affiliation(s)
- J O Gonatas
- Department of Pathology and Laboratory Medicine, University of Pennsylvania School of Medicine, Philadelphia 19104-6079
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25
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Gabel CA, Foster SA. Postendocytic maturation of acid hydrolases: evidence of prelysosomal processing. J Biophys Biochem Cytol 1987; 105:1561-70. [PMID: 2959666 PMCID: PMC2114675 DOI: 10.1083/jcb.105.4.1561] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
The mannose 6-phosphate (Man 6-P) receptor operates to transport both endogenous newly synthesized acid hydrolases and extracellular enzymes to the lysosomal compartment. In a previous study (Gabel, C. A., and S. A. Foster, 1986, J. Cell Biol., 103:1817-1827), we noted that beta-glucuronidase molecules internalized by mouse L-cells via the Man 6-P receptor undergo a proteolytic cleavage and a limited dephosphorylation. In this report, we present evidence that indicates that the postendocytic alterations of the acid hydrolase molecules occur at a site through which the enzymes pass en route to the lysosomal compartment. Mouse L-cells incubated at 20 degrees C with beta-glucuronidase (isolated from mouse macrophage secretions) internalize the enzyme in a process that is inhibited by Man 6-P but unaffected by cycloheximide. As such, the linear accumulation of the ligand observed at 20 degrees C appears to occur through the continued recycling of the cell surface Man 6-P receptor. The subcellular distribution of the internalized ligands was assessed after homogenization of the cells and fractionation of the extracts by density gradient centrifugation. In contrast to the accumulation of the ligand within lysosomes at 37 degrees C, the beta-glucuronidase molecules internalized by the L cells at 20 degrees C accumulate within a population of vesicles that sediment at the same density as endocytic vesicles. Biochemical analysis of the internalized ligands indicates that: (a) the subunit molecular mass of both beta-glucuronidase and beta-galactosidase decrease upon cell association relative to the input form of the enzymes, and (b) the beta-glucuronidase molecules experience a limited dephosphorylation such that high-mannose-type oligosaccharides containing two phosphomonoesters are converted to single phosphomonoester forms. The same two post-endocytic alterations occur after the internalization of beta-glucuronidase by human I-cell disease fibroblasts, despite the low acid hydrolase content of these cells. The results indicate, therefore, that acid hydrolases internalized via the Man 6-P receptor are processed within the endocytic compartment. In that endogenous newly synthesized acid hydrolases display similar alterations during their maturation, the results further suggest that the endosomal compartment is involved in the sorting of ligands transported via both the cell surface and intracellular Man 6-P receptor.
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Affiliation(s)
- C A Gabel
- Department of Anatomy and Cell Biology, College of Physicians and Surgeons, Columbia University, New York 10032
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26
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Pfeffer SR. The endosomal concentration of a mannose 6-phosphate receptor is unchanged in the absence of ligand synthesis. J Biophys Biochem Cytol 1987; 105:229-34. [PMID: 3038925 PMCID: PMC2114928 DOI: 10.1083/jcb.105.1.229] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
The cation-independent mannose-6-phosphate (Man-6-P) receptor is involved in the targeting of newly synthesized lysosomal hydrolases. To investigate the intracellular distribution of this receptor, a conjugate of lactoperoxidase coupled to asialoorosomucoid was used to catalyze its iodination within the endosomes of human hepatoma (HepG2) cells. The 215-kD, cation-independent Man-6-P receptor was iodinated by this procedure as shown by pentamannosyl-6-phosphate-Sepharose affinity chromatography and by immunoprecipitation of labeled cell extracts. The amount of this receptor detected in endosomes was found to be unchanged after inhibition of protein synthesis with cycloheximide. If the Man-6-P receptor accumulates in the Golgi apparatus in the absence of lysosomal hydrolase synthesis, it should have been correspondingly depleted from endosomes after a period of cycloheximide treatment, because these pools of receptor are in rapid equilibrium. Therefore, these data suggest that newly synthesized ligands are not required for the transport of the cation-independent Man-6-P receptor from the Golgi apparatus to endosomes.
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27
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Lemansky P, Hasilik A, von Figura K, Helmy S, Fishman J, Fine RE, Kedersha NL, Rome LH. Lysosomal enzyme precursors in coated vesicles derived from the exocytic and endocytic pathways. J Cell Biol 1987; 104:1743-8. [PMID: 2884223 PMCID: PMC2114498 DOI: 10.1083/jcb.104.6.1743] [Citation(s) in RCA: 55] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
The molecular forms of two lysosomal enzymes, cathepsin C and cathepsin D, have been examined in lysosomes and coated vesicles (CVs) of rat liver. In addition, the relative proportion of these lysosomal enzymes residing in functionally distinct CV subpopulations was quantitated. CVs contained newly synthesized precursor forms of the enzymes in contrast to lysosomes where only the mature forms were detected. Exocytic and endocytic CV subpopulations were prepared by two completely different protocols. One procedure, a density shift method, uses cholinesterase to alter the density of CVs derived from exocytic or endocytic pathways. The other relies on electrophoretic heterogeneity to accomplish the CV subfractionation. Subpopulations of CVs prepared by either procedure showed similar results, when examined for their relative proportion of cathepsin C and cathepsin D precursors. Within the starting CV preparation, exocytic CVs contained approximately 80-90% of the total steady-state levels of these enzymes while the level in the endocytic population was approximately 10-13%. The implications of these findings are discussed with regard to lysosome trafficking.
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28
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Intracellular traffic of the mannose 6-phosphate receptor and its ligands. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 1987; 225:199-212. [PMID: 2969175 DOI: 10.1007/978-1-4684-5442-0_17] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The role of the mannose 6-phosphate recognition marker and the phosphomannosyl receptor in the intracellular transport of acid hydrolases is well established. Several details of the process, however, are presently unclear and warrant further investigation (Table 1). The development of in vitro systems for the reconstitution of receptor-mediated endocytosis and intracellular transport, together with the application of the techniques of molecular biology to this field, should lead to major advances in our understanding of the targeting of enzymes to lysosomes.
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29
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Biosynthesis, glycosylation, movement through the Golgi system, and transport to lysosomes by an N-linked carbohydrate-independent mechanism of three lysosomal integral membrane proteins. J Biol Chem 1986. [DOI: 10.1016/s0021-9258(18)66630-x] [Citation(s) in RCA: 143] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
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30
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Synthesis of the 6- and 6′-phosphates of 8-methoxycarbonyloctyl 2-O-α-d-mannopyranosyl-α-d-mannopyranoside. Carbohydr Res 1986. [DOI: 10.1016/s0008-6215(00)90133-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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31
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Abstract
The Golgi complex is a series of membrane compartments through which proteins destined for the plasma membrane, secretory vesicles, and lysosomes move sequentially. A model is proposed whereby these three different classes of proteins are sorted into different vesicles in the last Golgi compartment, the trans Golgi network. This compartment corresponds to a tubular reticulum on the trans side of the Golgi stack, previously called Golgi endoplasmic reticulum lysosomes (GERL).
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32
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Bourguignon LY, Balazovich K, Suchard SJ, Hindsgaul O, Pierce M. Endocytosis of mannose-6-phosphate binding sites by mouse T-lymphoma cells. J Cell Physiol 1986; 127:146-61. [PMID: 2870071 DOI: 10.1002/jcp.1041270118] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The endocytosis and intracellular transport of mannose-6-phosphate conjugated to bovine serum albumin (Man-6-P:BSA) by mouse T-lymphoma cells were investigated in detail using several methods of analysis, both morphological and biochemical. Man-6-P:BSA was labeled with fluorescein or 125I and used to locate both surface and intracellular Man-6-P binding sites by light or electron microscopy, respectively. Incubation of cells with either fluorescent- or 125I-labeled Man-6-P:BSA at 0 degree C revealed a uniform distribution of the Man-6-P binding sites over the cell surface. Competition experiments indicate that the Man-6-P:BSA binding sites on the cell surface are the same receptors that can recognize lysosomal hydrolases. After as little as 1 min incubation at 37 degrees C, endocytosis of Man-6-P binding sites was clearly observed to occur through regions of the plasma membrane and via vesicles that also bound anticlathrin antibody. After a 5-15-min incubation of cells at 37 degrees C, the internalized ligand was detected first in the cis region of the Golgi apparatus and then in the Golgi stacks using both autoradiography and immunocytochemistry to visualize the ligand. The appearance of Man-6-P:BSA in the Golgi region after 15-30 min was confirmed by subcellular fractionation, which demonstrated an accumulation of Man-6-P:BSA in light membrane fractions that corresponded with the Golgi fractions. After a 30-min incubation at 37 degrees C, the internalized Man-6-P binding sites were localized primarily in lysosomal structures whose membrane but not lumen co-stained for acid phosphatase. These results demonstrate a temporal participation of clathrin-containing coated vesicles during the initial endocytosis of Man-6-P binding sites and that one step in the Man-6-P:BSA transport pathway between plasma membrane and the lysosomal structure can involve a transit through the Golgi stacks.
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33
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Geuze HJ, Slot JW, Strous GJ, Hasilik A, von Figura K. Possible pathways for lysosomal enzyme delivery. J Cell Biol 1985; 101:2253-62. [PMID: 2933416 PMCID: PMC2114005 DOI: 10.1083/jcb.101.6.2253] [Citation(s) in RCA: 216] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Immunogold double-labeling and ultrathin cryosections were used to compare the subcellular distribution of albumin, mannose 6-phosphate receptor (MPR), galactosyltransferase, and the lysosomal enzymes cathepsin D, beta-hexosaminidase, and alpha-glucosidase in Hep G2 cells. MPR and lysosomal enzymes were found throughout the stack of Golgi cisternae and in a trans-Golgi reticulum (TGR) of smooth-surfaced tubules with coated buds and vesicles. The trans-Golgi orientation of TGR was ascertained by the co-localization with galactosyltransferase. MPR was particularly abundant in TGR and CURL, the compartment of uncoupling receptors and ligands. Both TGR and CURL also contained lysosomal enzymes, but endogenous albumin was detected in TGR only. The coated buds on TGR tubules contained MPR, lysosomal enzymes, as well as albumin. MPR and lysosomal enzymes were also found in coated pits of the plasma membrane. CURL tubules seemed to give rise to smooth vesicles, often of the multivesicular body type. In CURL, the enzymes were found in the lumina of the smooth vesicles while MPR prevailed in the tubules. These observations suggest a role of CURL in transport of lysosomal enzymes to lysosomes. When the cells were treated with the lysosomotropic amine primaquine, binding of anti-MPR to the cells in culture was reduced by half. Immunocytochemistry showed that MPR accumulated in TGR, especially in coated buds. Since these buds contain endogenous albumin and lysosomal enzymes also, these data suggest that coated vesicles originating from TGR provide for a secretory route in Hep G2 cells and that this pathway is followed by the MPR system as well.
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Sahagian GG, Steer CJ. Transmembrane orientation of the mannose 6-phosphate receptor in isolated clathrin-coated vesicles. J Biol Chem 1985. [DOI: 10.1016/s0021-9258(17)39312-2] [Citation(s) in RCA: 32] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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35
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Geuze HJ, Slot JW, Strous GJ, Hasilik A, Von Figura K. Ultrastructural localization of the mannose 6-phosphate receptor in rat liver. J Biophys Biochem Cytol 1984; 98:2047-54. [PMID: 6327724 PMCID: PMC2113062 DOI: 10.1083/jcb.98.6.2047] [Citation(s) in RCA: 146] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
An affinity-purified rabbit antibody against rat liver mannose 6-phosphate receptor (MP-R) was prepared. The antibody was directed against a 215 kd-polypeptide and it recognized both ligand-occupied and free receptor. Anti-MP-R was used for immunofluorescence and immunoelectron microscopy of cryosections from rat liver. MP-R was demonstrated in all parenchymal liver cells, but not in endothelial lining cells. MP-R labeling was found at the entire plasma membrane, in coated pits and coated vesicles, in the compartment of uncoupling receptor and ligand, and in the Golgi complex. Lysosomes showed only scarce MP-R label. In double-labeling immunoelectron microscopy, MP-R co-localized with albumin in the Golgi cisternae and in secretory vesicles with lipoprotein particles. Cathepsin D was associated with MP-R in the Golgi cisternae. This finding indicates that MP-R/cathepsin D complexes traverse the Golgi complex on their way to the lysosomes. The possible involvement of CURL in lysosomal enzyme targeting is discussed.
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37
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Brown WJ, Farquhar MG. The mannose-6-phosphate receptor for lysosomal enzymes is concentrated in cis Golgi cisternae. Cell 1984; 36:295-307. [PMID: 6319015 DOI: 10.1016/0092-8674(84)90223-x] [Citation(s) in RCA: 239] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Mannose-6-phosphate (Man-6-P) receptors for lysosomal enzymes were localized by immunocytochemistry in several secretory and adsorptive cell types using monospecific antireceptor antibodies. By immunofluorescence, the receptors were found in the Golgi region of polarized cells. When localized by immunoperoxidase at the electron microscope level, they were detected in Golgi cisternae, coated vesicles, endosomes, and lysosomes of all cell types examined (hepatocytes, exocrine pancreatic and epididymal epithelia). Within the Golgi complex, immunoreactive receptors were restricted in their distribution to one or two cisternae on the cis side of the Golgi stacks. They were not detected in trans Golgi or GERL cisternae. Based on their high concentration of Man-6-P receptors, we propose that the cis Golgi cisternae represent the site where the secretory and lysosomal pathways diverge: lysosomal enzymes bearing the Man-6-P recognition marker bind to Man-6-P receptors in this location and are delivered to endosomes and lysosomes via coated vesicles.
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Mitchell DC, Maler T, Jourdian GW. Detergent dissociation of bovine liver phosphomannosyl binding protein. J Cell Biochem 1984; 24:319-30. [PMID: 6088561 DOI: 10.1002/jcb.240240403] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
We have reported previously the isolation and partial characterization of a 215-kilodalton (Kd) phosphomannosyl binding protein from bovine liver membranes [3,9]. In the present studies evidence is presented that the binding protein is an aggregate. Four N-terminal amino acids were detected, and the complex could be dissociated into subunits. Bovine liver membranes were extracted with the detergent, Zwittergent, in the presence of protease inhibitors. The extract was subjected to affinity chromatography on phosphomannan-Sepharose 4B, and proteins with apparent Mr values of 215 and 57 Kd were eluted with mannose 6-phosphate. As reported previously, extraction with Triton X-100 yielded only the higher molecular weight material. When the binding protein was incubated at 4 degrees C in the presence of Zwittergent TM 3-14 the 215-Kd form slowly dissociated into smaller subunits; after two months, the major species had an apparent Mr of 57 Kd. The subunits derived from the binding protein were recognized by antiserum raised against purified binding protein. Dissociation of the binding protein by Zwittergent was enhanced by incubation at 37 degrees C, the presence of dithiothreitol, and low pH values. The subunit mixture enriched in the 57-Kd subunit had a lowered ability to bind ligands containing the phosphomannosyl recognition marker. Binding was partially restored (greater than 48% of the initial value) when dissociated receptor was back exchanged with Triton X-100.
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39
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Willingham MC, Pastan I. Endocytosis and exocytosis: current concepts of vesicle traffic in animal cells. INTERNATIONAL REVIEW OF CYTOLOGY 1984; 92:51-92. [PMID: 6150907 DOI: 10.1016/s0074-7696(08)61324-8] [Citation(s) in RCA: 78] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Animal cells have specific pathways to transport macromolecules from their surrounding environment to their interior, and from internal compartments to the cell surface or other intracellular locations. Many of these movements appear to be receptor-dependent processes in which specific membrane receptors bind macromolecules, segregate them into discrete membrane-limited compartments, and move the molecules to new locations. Such processes include the clustering and internalization of receptor-bound ligands at the cell surface in clathrin-coated pits, the formation of endocytic vesicles (receptosomes) from coated pits, the movement of receptosomes by saltatory motion to the Golgi system, the concentration of materials in the coated pits of the Golgi system that are destined for delivery to lysosomes, and the directed traffic of materials destined for exocytosis out of the Golgi to the cell surface. This review describes some of the experiments which have led to our current understanding of the various organelles involved in this traffic and some of the biochemical mechanisms involved.
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40
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Willingham MC, Pastan I. Endocytosis and membrane traffic in cultured cells. RECENT PROGRESS IN HORMONE RESEARCH 1984; 40:569-87. [PMID: 6207568 DOI: 10.1016/b978-0-12-571140-1.50018-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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41
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Dickson RB, Beguinot L, Hanover JA, Richert ND, Willingham MC, Pastan I. Isolation and characterization of a highly enriched preparation of receptosomes (endosomes) from a human cell line. Proc Natl Acad Sci U S A 1983; 80:5335-9. [PMID: 6310570 PMCID: PMC384250 DOI: 10.1073/pnas.80.17.5335] [Citation(s) in RCA: 60] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Receptor-mediated endocytosis proceeds by transfer of receptor-ligand complexes from clathrin-coated pits at the cell surface to uncoated endocytic vesicles termed receptosomes (or endosomes). These vesicles have now been purified more than 37-fold based on their content of newly internalized epidermal growth factor. 125I-labeled EGF was bound to human KB carcinoma cells at 4 degrees C, and then the cells were warmed to 37 degrees C for 8 min and disrupted. The purification scheme involved density gradient centrifugation on colloidal silica and sucrose and gel filtration on Sephacryl S-1000. Relative to homogenate, receptosomes are enriched 4.3-fold in their cholesterol content and depleted in enzyme markers for plasma membranes (2- to 3-fold) and lysosomes (9-fold). Receptosomes have a polypeptide composition that is different from plasma membrane, lysosome, and other homogenate fractions. They are enriched in transferrin receptors (30-fold) and in unidentified Mr 70,000-75,000 glycoprotein(s); they contain phosphomannosyl receptors. They do not contain detectable amounts of clathrin.
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42
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Sahagian GG, Neufeld EF. Biosynthesis and turnover of the mannose 6-phosphate receptor in cultured Chinese hamster ovary cells. J Biol Chem 1983. [DOI: 10.1016/s0021-9258(18)32340-8] [Citation(s) in RCA: 100] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
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Ciechanover A, Schwartz AL, Lodish HF. Sorting and recycling of cell surface receptors and endocytosed ligands: the asialoglycoprotein and transferrin receptors. J Cell Biochem 1983; 23:107-30. [PMID: 6327736 DOI: 10.1002/jcb.240230111] [Citation(s) in RCA: 104] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
With few exceptions, receptor-mediated endocytosis of specific ligands is mediated through clustering of receptor-ligand complexes in coated pits on the cell surface, followed by internalization of the complex into endocytic vesicles. During this process, ligand-receptor dissociation occurs, most probably in a low pH prelysosomal compartment. In most cases the ligand is ultimately directed to the lysosomes, wherein it is degraded, while the receptor recycles to the cell surface. We have studied the kinetics of internalization and recycling of both the asialoglycoprotein receptor and the transferrin receptor in a human hepatoma cell line. By employing both biochemical and morphological/immunocytochemical approaches, we have gained some insight into the complex mechanisms which govern receptor recycling as well as ligand sorting and targeting. We can, in particular, explain why transferrin is exocytosed intact from the cells, while asialoglycoproteins are degraded in lysosomes. We have also localized the intracellular site at which endocytosed receptor and ligand dissociate.
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