Faculty Opinions recommendation of Requirement of the human GARP complex for mannose 6-phosphate-receptor-dependent sorting of cathepsin D to lysosomes.

2014 ◽  
Author(s):  
Paul Gleeson
Keyword(s):  
Cathepsin D ◽  
Mannose 6 Phosphate ◽  
Garp Complex

scholarly journals Requirement of the Human GARP Complex for Mannose 6-phosphate-receptor-dependent Sorting of Cathepsin D to Lysosomes

2008 ◽  
Vol 19 (6) ◽  
pp. 2350-2362 ◽  
Author(s):  
F. Javier Pérez-Victoria ◽  
Gonzalo A. Mardones ◽  
Juan S. Bonifacino
Keyword(s):  
Shiga Toxin ◽  
Cathepsin D ◽  
Culture Medium ◽  
Retrograde Transport ◽  
Acid Hydrolase ◽  
Acid Hydrolases ◽  
General Role ◽  
B Subunit ◽  
Mannose 6 Phosphate ◽  
Garp Complex

The biosynthetic sorting of acid hydrolases to lysosomes relies on transmembrane, mannose 6-phosphate receptors (MPRs) that cycle between the TGN and endosomes. Herein we report that maintenance of this cycling requires the function of the mammalian Golgi-associated retrograde protein (GARP) complex. Depletion of any of the three GARP subunits, Vps52, Vps53, or Vps54, by RNAi impairs sorting of the precursor of the acid hydrolase, cathepsin D, to lysosomes and leads to its secretion into the culture medium. As a consequence, lysosomes become swollen, likely due to a buildup of undegraded materials. Missorting of cathepsin D in GARP-depleted cells results from accumulation of recycling MPRs in a population of light, small vesicles downstream of endosomes. These vesicles might correspond to intermediates in retrograde transport from endosomes to the TGN. Depletion of GARP subunits also blocks the retrograde transport of the TGN protein, TGN46, and the B subunit of Shiga toxin. These observations indicate that the mammalian GARP complex plays a general role in the delivery of retrograde cargo into the TGN. We also report that a Vps54 mutant protein in the Wobbler mouse strain is active in retrograde transport, thus explaining the viability of these mutant mice.

scholarly journals Mannose 6-phosphate-independent targeting of cathepsin D to lysosomes in HepG2 cells.

1991 ◽  
Vol 266 (35) ◽  
pp. 23586-23592 ◽  
Author(s):  
S. Rijnboutt ◽  
A.J. Kal ◽  
H.J. Geuze ◽  
H. Aerts ◽  
G.J. Strous
Keyword(s):  
Hepg2 Cells ◽  
Cathepsin D ◽  
Mannose 6 Phosphate

The lysosomal protease cathepsin D is efficiently sorted to and secreted from regulated secretory compartments in the rat basophilic/mast cell line RBL

2000 ◽  
Vol 113 (18) ◽  
pp. 3289-3298 ◽  
Author(s):  
A. Dragonetti ◽  
M. Baldassarre ◽  
R. Castino ◽  
M. Demoz ◽  
A. Luini ◽  
...  
Keyword(s):  
Mast Cell ◽  
Mast Cells ◽  
Cell Line ◽  
Cathepsin D ◽  
Secretory Granules ◽  
Bioactive Molecules ◽  
Blue Staining ◽  
Lysosomal Protease ◽  
Mannose 6 Phosphate ◽  
Mast Cell Line

Basophils and mast cells contain a peculiar class of inflammatory granules that discharge their content upon antigen-mediated crosslinking of IgE-membrane receptors. The pathways for granule biogenesis and exocytosis in these cells are still largely obscure. In this study we employed the rat basophilic leukemia (RBL)/mast cell line to verify the hypothesis that inflammatory granules share common bioactive molecules and functional properties with lysosomes. We demonstrate that inflammatory granules, as identified by the monoclonal 5G10 antibody (which recognises an integral membrane protein) or by Toluidine Blue staining, have an intralumenal acidic pH, possess lysosomal enzymes and are accessible by fluid-phase and membrane endocytosis markers. In addition, we studied the targeting, subcellular localisation and regulated secretion of the lysosomal aspartic protease cathepsin D (CD) as affected by IgE receptor stimulation in order to obtain information on the pathways for granule biogenesis and exocytosis. Stimulation with DNP-BSA of specific IgE-primed RBL cells led to a prompt release of processed forms of CD, along with other mature lysosomal hydrolases. This release could be prevented by addition of EGTA, indicating that it was dependent on extracellular calcium influx. Antigen stimulation also induced exocytosis of immature CD forms accumulated by ammonium chloride, suggesting the existence of an intermediate station in the pathway for granule biogenesis still sensitive to regulated exocytosis. The targeting of molecules to secretory granules may occur via either a mannose-6-phosphate-dependent or mannose-6-phosphate-independent pathway. We conclude that endosomes and lysosomes in basophils/mast cells can act as regulated secretory granules or actually identify with them.

ENDOCYTOSIS OF THE SECRETED PRO-CATHEPSIN D INTO BREAST CANCER CELLS IS PARTLY INDEPENDENT OF THE MANNOSE-6-PHOSPHATE RECEPTORS

1996 ◽  
Vol 88 (1-2) ◽  
pp. 82-82
Author(s):  
Valérie LAURENT ◽  
Reza FARNOUD ◽  
Annick LUCAS ◽  
Christian ROUGEOT ◽  
Marcel GARCIA ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cancer Cells ◽  
Cathepsin D ◽  
Breast Cancer Cells ◽  
Mannose 6 Phosphate

scholarly journals Mutant Rab7 Causes the Accumulation of Cathepsin D and Cation-independent Mannose 6–Phosphate Receptor in an Early Endocytic Compartment

1998 ◽  
Vol 140 (5) ◽  
pp. 1075-1089 ◽  
Author(s):  
Barry Press ◽  
Yan Feng ◽  
Bernard Hoflack ◽  
Angela Wandinger-Ness
Keyword(s):  
Cathepsin D ◽  
Dominant Negative ◽  
Dominant Negative Mutant ◽  
Lysosomal Hydrolases ◽  
Endocytic Compartment ◽  
Lysosome Biogenesis ◽  
Late Endosomes ◽  
Mannose 6 Phosphate ◽  
Lysosomal Membrane Glycoprotein ◽  
Mutant Forms

Stable BHK cell lines inducibly expressing wild-type or dominant negative mutant forms of the rab7 GTPase were isolated and used to analyze the role of a rab7-regulated pathway in lysosome biogenesis. Expression of mutant rab7N125I protein induced a dramatic redistribution of cation-independent mannose 6–phosphate receptor (CI-MPR) from its normal perinuclear localization to large peripheral endosomes. Under these circumstances ∼50% of the total receptor and several lysosomal hydrolases cofractionated with light membranes containing early endosome and Golgi markers. Late endosomes and lysosomes were contained exclusively in well-separated, denser gradient fractions. Newly synthesized CI-MPR and cathepsin D were shown to traverse through an early endocytic compartment, and functional rab7 was crucial for delivery to later compartments. This observation was evidenced by the fact that 2 h after synthesis, both markers were more prevalent in fractions containing light membranes. In addition, both were sensitive to HRP-DAB– mediated cross-linking of early endosomal proteins, and the late endosomal processing of cathepsin D was impaired. Using similar criteria, the lysosomal membrane glycoprotein 120 was not found accumulated in an early endocytic compartment. The data are indicative of a post-Golgi divergence in the routes followed by different lysosome-directed molecules.

Oestrogen-induced pro-cathepsin D in breast cancer: from biology to clinical applications

1989 ◽  
Vol 95 ◽  
pp. 107-118
Author(s):  
Henri Rochefort ◽  
Patrick Augereau ◽  
Pierre Briozzo ◽  
François Capony ◽  
Vincent Cavailles ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cancer Cells ◽  
Cathepsin D ◽  
Breast Cancer Cells ◽  
Mammary Epithelial Cells ◽  
Tissue Type ◽  
Breast Cancer Cell Lines ◽  
Lysosomal Protease ◽  
Mannose 6 Phosphate

SynopsisIn addition to secreted growth factors, acting as autocrine or paracrine mitogens, breast cancer cells secrete other proteins whose function and significance in mammary carcinogenesis may be important. Among them, proteases are particularly interesting since it has been suggested that they play a role in metastatic process, and since at least two of them, the tissue type plasminogen activator and pro-cathepsin D, the precursor of a lysosomal protease, are induced by oestrogens and secreted in excess in some mammary cancer cells.In oestrogen-receptor-positive human breast cancer cell lines (MCF7, ZR75–1), oestrogens stimulate cell proliferation and specifically increase the secretion into the culture medium of a 52,000-dalton (52-kDa) glycoprotein identified as the secreted precursor of a cathepsin D bearing mannose-6-phosphate signals, which is routed to lysosomesviamannose-6-phosphate-IGF-II receptors. We have determined the structure of this procathepsin D by sequencing its complete cDNA sequence, its chromosomal localisation and its transcriptional regulation by oestrogens and other mitogens. In breast cancer cells, pro-cathepsin D production and secretion is much higher and its processing is altered compared to normal mammary epithelial cells in culture.In vitro, pro-cathepsin D acts as an autocrine mitogen on breast cancer cells and can be activated at acidic pH to degrade extracellular matrix, suggesting a role in mediating the effect of oestrogens on tumour growth and invasion. Retrospective clinical studies indicate a significant correlation between high 52-kDa cathepsin D concentrations in the cytosol of primary breast cancer and poor prognosis (Danish Breast Cancer Group, S. Thorpe, Copenhagen). We propose that among the proteases secreted by cancer cells, 52-kDa cathepsin D is important both as a tissue marker in breast cancer and as a potential factor involved in carcinogenesis.

Endocytosis of pro-cathepsin D into breast cancer cells is mostly independent of mannose-6-phosphate receptors

1998 ◽  
Vol 111 (17) ◽  
pp. 2539-2549 ◽  
Author(s):  
V. Laurent-Matha ◽  
M.R. Farnoud ◽  
A. Lucas ◽  
C. Rougeot ◽  
M. Garcia ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cancer Cells ◽  
Cell Lines ◽  
Cancer Cell ◽  
Cathepsin D ◽  
Breast Cancer Cells ◽  
Cancer Cell Lines ◽  
Breast Cancer Cell Lines ◽  
Mannose 6 Phosphate ◽  
Mcf 7

Cathepsin D trafficking is altered in cancer cells, leading to increased secretion of the pro-enzyme, which can be reinternalized by the same cancer cells and by stromal cells. We studied pro-cathepsin D endocytosis in two human breast cancer cell lines (MDA-MB231, MCF-7) and in human normal fibroblasts. Pro-enzyme uptake was studied indirectly through immunofluorescence analysis of anti-pro-cathepsin D monoclonal antibodies internalized in living cells. Both cancer cell lines internalized the pro-cathepsin D-antibody complex into endosomal compartments in the presence of 10 mM mannose-6-phosphate. Non-malignant fibroblasts, which do not secrete pro-cathepsin D, only internalized anti-cathepsin D antibody when purified pro-cathepsin D was added and this endocytosis was totally inhibited by mannose-6-phosphate. Cathepsin D endocytosis in cancer cells was not mediated by lectins or another receptor binding the cathepsin profragment. It was not due to fluid endocytosis, since another protein pS2 secreted by MCF-7 was not endocytosed with its antibody in the same conditions. Double-immunofluorescence and confocal microscopy analyses revealed that antibodies specific to pro-cathepsin D (M2E8) and to the mannose-6-phosphate/IGFII receptor were co-internalized independently in non-permeabilized MDA-MB231 cells and MCF-7 cells, but not in fibroblasts. Moreover, when metabolically labelled pro-cathepsin D secreted by MCF-7 or MDA-MB231 cells was incubated with homologous or heterologous non-radioactive cells, the time-dependent uptake and maturation of the pro-enzyme into fibroblasts were totally inhibited by mannose-6-phosphate, whereas they were not in the two breast cancer cell lines. The percentage of mannose-6-phosphate-independent binding of radioactively labelled pro-cathepsin D to MDA-MB231 cells at 16 degrees C was higher (7–8%) at low pro-cathepsin D concentration than at high concentration (1.5%), indicating the presence of saturable binding site(s) at the cell surface that are different from the mannose-6-phosphate receptors. We conclude that, in contrast to fibroblasts, breast cancer cells can endocytose the secreted pro-cathepsin D by a cell surface receptor that is different from the mannose-6-phosphate receptors or other lectins. The nature of this alternative receptor and its significance in the action of secreted pro-cathepsin D remain to be elucidated.

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