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Recycling of a glycosylphosphatidylinositol-anchored heparan sulphate proteoglycan (glypican) in skin fibroblasts

Fransson, Lars-Åke LU ; Edgren, Gudrun LU ; Havsmark, Birgitta LU and Schmidtchen, Artur LU (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)
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author
organization
publishing date
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
2008-07-24 15:54:05
date last changed
2017-02-19 04:05:41
@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},
  keyword      = {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},
  volume       = {5},
  year         = {1995},
}