Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
14
pubmed:dateCreated
1992-6-9
pubmed:abstractText
Rat ovarian granulosa cells synthesize two distinct species of plasma membrane-intercalated heparan sulfate (HS) proteoglycans; glycosylphosphatidylinositol (GPI)-anchored and core protein-intercalated HS proteoglycans. Both species of HS proteoglycans are primarily localized on the plasma membrane. Cell surface localization of GPI-anchored and protein-intercalated HS proteoglycans can be determined by their accessibility to exogenously added phosphatidylinositol-specific phospholipase C (PI-PLC) and trypsin, respectively. Kinetic parameters for the processes involving their transfer from the Golgi to the cell surface, endocytosis and secretion, and the modes of intracellular degradation were determined by metabolic labeling experiments using [35S]sulfate and various chase protocols in combination with the use of PI-PLC and trypsin in rat ovarian granulosa cells. The experiments demonstrated that (i) both HS proteoglycan species are transferred from the Golgi to the cell surface with an average transit time of approximately 12 min. (ii) GPI-anchored HS proteoglycans are endocytosed with a t1/2 approximately 3 h, without being shed into the medium, and they are rapidly degraded, t1/2 approximately 25 min, without generating recognizable degradation intermediates. (iii) Protein-intercalated HS proteoglycans are partly (approximately 30%) shed from the cell surface into the medium and the remaining approximately 70% are endocytosed with a t1/2 approximately 4 h. After endocytosis, they undergo a slow (t1/2 approximately 4 h) stepwise degradation generating distinct HS oligosaccharides as degradation intermediates. These results indicate that the GPI-anchored and the protein-intercalated HS proteoglycans have distinct secretory, endocytotic, and intracellular degradation pathways probably due to the differences in their anchor structures.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
267
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
9505-11
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed-meshheading:1533636-Animals, pubmed-meshheading:1533636-Cell Membrane, pubmed-meshheading:1533636-Cells, Cultured, pubmed-meshheading:1533636-Chromatography, Gel, pubmed-meshheading:1533636-Endocytosis, pubmed-meshheading:1533636-Female, pubmed-meshheading:1533636-Glycolipids, pubmed-meshheading:1533636-Glycosylphosphatidylinositols, pubmed-meshheading:1533636-Golgi Apparatus, pubmed-meshheading:1533636-Granulosa Cells, pubmed-meshheading:1533636-Heparan Sulfate Proteoglycans, pubmed-meshheading:1533636-Heparitin Sulfate, pubmed-meshheading:1533636-Kinetics, pubmed-meshheading:1533636-Models, Biological, pubmed-meshheading:1533636-Phosphatidylinositols, pubmed-meshheading:1533636-Proteoglycans, pubmed-meshheading:1533636-Rats, pubmed-meshheading:1533636-Rats, Inbred Strains, pubmed-meshheading:1533636-Sulfates, pubmed-meshheading:1533636-Sulfur Radioisotopes
pubmed:year
1992
pubmed:articleTitle
Glycosylphosphatidylinositol-anchored and core protein-intercalated heparan sulfate proteoglycans in rat ovarian granulosa cells have distinct secretory, endocytotic, and intracellular degradative pathways.
pubmed:affiliation
Bone Research Branch, National Institute of Dental Research, National Institutes of Health, Bethesda, Maryland 20892.
pubmed:publicationType
Journal Article