Recycling of a glycosylphosphatidylinositol-anchored heparan sulphate proteoglycan (glypican) in skin fibroblasts
(1995) In Glycobiology 5(4). p.407-415- Abstract
- We have used suramin and brefeldin A to investigate the nature of a heparan sulphate proteoglycan that appears to recycle from the cell surface to intracellular compartments which synthesize new heparan sulphate chains. Suramin, which would block internalization and deglycanation of a putative recycling cell surface proteoglycan, markedly increases the yield of a membrane-bound proteoglycan with a core protein of 60-70 kDa and unusually long heparan sulphate side chains. When transport of newly made core proteins to their Golgi sites for glycosaminoglycan assembly is blocked, by using brefeldin A, [3H]glucosamine and [35S]sulphate incorporation into cell surface-bound heparan sulphate proteoglycan can still take place. After chemical... (More)
- We have used suramin and brefeldin A to investigate the nature of a heparan sulphate proteoglycan that appears to recycle from the cell surface to intracellular compartments which synthesize new heparan sulphate chains. Suramin, which would block internalization and deglycanation of a putative recycling cell surface proteoglycan, markedly increases the yield of a membrane-bound proteoglycan with a core protein of 60-70 kDa and unusually long heparan sulphate side chains. When transport of newly made core proteins to their Golgi sites for glycosaminoglycan assembly is blocked, by using brefeldin A, [3H]glucosamine and [35S]sulphate incorporation into cell surface-bound heparan sulphate proteoglycan can still take place. After chemical biotinylation of cell surface proteins in brefeldin A-treated cells, followed by metabolic [35S]sulphation in the presence of the same drug, biotin-tagged [35S]proteoglycan can be demonstrated, indicating the presence of recycling proteoglycan species. By pre-labelling cells with [3H]leucine or [3H]inositol in the presence of suramin, followed by chase labelling with [35S]sulphate in the presence of brefeldin A, a 3H- and 35S-labelled, hydrophobic heparan sulphate proteoglycan with a core protein of 60-65 kDa is obtained. The proteoglycan loses its hydrophobicity when glucosamine-inositol bonds are cleaved, indicating that it is membrane bound via a glycosylphosphatidylinositol anchor. However, treatment with phosphatidylinositol-specific phospholipase C has no effect, suggesting that the inositol moiety may be acylated. We propose that a portion of the lipid-anchored proteoglycan glypican is internalized, recycled via the Golgi, where heparan sulphate chains are added, and finally re-deposited at the cell surface. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/1108732
- author
- Fransson, Lars-Åke LU ; Edgren, Gudrun LU ; Havsmark, Birgitta LU and Schmidtchen, Artur LU
- organization
- publishing date
- 1995
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- glycosylphosphatidylinositol-anchored/glypican/ heparan sulphate/proteoglycan/recycling
- in
- Glycobiology
- volume
- 5
- issue
- 4
- pages
- 407 - 415
- publisher
- Oxford University Press
- external identifiers
-
- pmid:7579795
- scopus:0028998505
- ISSN
- 1460-2423
- language
- English
- LU publication?
- yes
- id
- f022a1d2-5abf-404f-aa95-a3f5bd1aef0b (old id 1108732)
- alternative location
- http://glycob.oxfordjournals.org/cgi/reprint/5/4/407
- date added to LUP
- 2016-04-01 15:35:07
- date last changed
- 2025-04-04 14:21:32
@article{f022a1d2-5abf-404f-aa95-a3f5bd1aef0b,
abstract = {{We have used suramin and brefeldin A to investigate the nature of a heparan sulphate proteoglycan that appears to recycle from the cell surface to intracellular compartments which synthesize new heparan sulphate chains. Suramin, which would block internalization and deglycanation of a putative recycling cell surface proteoglycan, markedly increases the yield of a membrane-bound proteoglycan with a core protein of 60-70 kDa and unusually long heparan sulphate side chains. When transport of newly made core proteins to their Golgi sites for glycosaminoglycan assembly is blocked, by using brefeldin A, [3H]glucosamine and [35S]sulphate incorporation into cell surface-bound heparan sulphate proteoglycan can still take place. After chemical biotinylation of cell surface proteins in brefeldin A-treated cells, followed by metabolic [35S]sulphation in the presence of the same drug, biotin-tagged [35S]proteoglycan can be demonstrated, indicating the presence of recycling proteoglycan species. By pre-labelling cells with [3H]leucine or [3H]inositol in the presence of suramin, followed by chase labelling with [35S]sulphate in the presence of brefeldin A, a 3H- and 35S-labelled, hydrophobic heparan sulphate proteoglycan with a core protein of 60-65 kDa is obtained. The proteoglycan loses its hydrophobicity when glucosamine-inositol bonds are cleaved, indicating that it is membrane bound via a glycosylphosphatidylinositol anchor. However, treatment with phosphatidylinositol-specific phospholipase C has no effect, suggesting that the inositol moiety may be acylated. We propose that a portion of the lipid-anchored proteoglycan glypican is internalized, recycled via the Golgi, where heparan sulphate chains are added, and finally re-deposited at the cell surface.}},
author = {{Fransson, Lars-Åke and Edgren, Gudrun and Havsmark, Birgitta and Schmidtchen, Artur}},
issn = {{1460-2423}},
keywords = {{glycosylphosphatidylinositol-anchored/glypican/
heparan sulphate/proteoglycan/recycling}},
language = {{eng}},
number = {{4}},
pages = {{407--415}},
publisher = {{Oxford University Press}},
series = {{Glycobiology}},
title = {{Recycling of a glycosylphosphatidylinositol-anchored heparan sulphate proteoglycan (glypican) in skin fibroblasts}},
url = {{http://glycob.oxfordjournals.org/cgi/reprint/5/4/407}},
volume = {{5}},
year = {{1995}},
}