scholarly journals Selective reentry of recycling cell surface glycoproteins to the biosynthetic pathway in human hepatocarcinoma HepG2 cells.

1995 ◽  
Vol 130 (3) ◽  
pp. 537-551 ◽  
Author(s):  
B Volz ◽  
G Orberger ◽  
S Porwoll ◽  
H P Hauri ◽  
R Tauber
Keyword(s):  
Cell Surface ◽  
Hepg2 Cells ◽  
Biosynthetic Pathway ◽  
Secretory Pathway ◽  
Surface Proteins ◽  
Early Secretory Pathway ◽  
Golgi Transport ◽  
Cell Surface Glycoproteins ◽  
Golgi Network ◽  
Surface Glycoproteins

Return of cell surface glycoproteins to compartments of the secretory pathway has been examined in HepG2 cells comparing return to the trans-Golgi network (TGN), the trans/medial- and cis-Golgi. Transport to these sites was studied by example of the transferrin receptor (TfR) and the serine peptidase dipeptidylpeptidase IV (DPPIV) after labeling these proteins with the N-hydroxysulfosuccinimide ester of biotin on the cell surface. This experimental design allowed to distinguish between glycoproteins that return to these biosynthetic compartments from the cell surface and newly synthesized glycoproteins that pass these compartments during biosynthesis en route to the surface. Reentry to the TGN was measured in that surface glycoproteins were desialylated with neuraminidase and were monitored for resialylation during recycling. Return to the trans-Golgi was traced measuring the transfer of [3H]fucose residues to recycling surface proteins by fucosyltransferases. To study return to the cis-Golgi, surface proteins were metabolically labeled in the presence of the mannosidase I inhibitor deoxymannojirimycin (dMM). As a result surface proteins retained N-glycans of the oligomannosidic type. Return to the site of mannosidase I in the medial/cis-Golgi was measured monitoring conversion of these glycans to those of the complex type after washout of dMM. Our data demonstrate that DPPIV does return from the cell surface not only to the TGN, but also to the trans-Golgi thus linking the endocytic to the secretory pathway. In contrast, no reentry to sites of mannosidase I could be detected indicating that the early secretory pathway is not or is only at insignificant rates accessible to recycling DPPIV. In contrast to DPPIV, TfR was very efficiently sorted from endosomes to the cell surface and did not return to the TGN or to other biosynthetic compartments in detectable amounts, indicating that individual surface proteins are subject to different sorting mechanisms or sorting efficiencies during recycling.

scholarly journals Two Endoplasmic Reticulum (ER) Membrane Proteins That Facilitate ER-to-Golgi Transport of Glycosylphosphatidylinositol-anchored Proteins

1999 ◽  
Vol 10 (4) ◽  
pp. 1043-1059 ◽  
Author(s):  
Wolfgang P. Barz ◽  
Peter Walter
Keyword(s):  
Endoplasmic Reticulum ◽  
Cell Surface ◽  
Secretory Pathway ◽  
Protein Transport ◽  
Protein Translocation ◽  
Sequence Similarity ◽  
Surface Proteins ◽  
Golgi Transport ◽  
Er Membrane

Many eukaryotic cell surface proteins are anchored in the lipid bilayer through glycosylphosphatidylinositol (GPI). GPI anchors are covalently attached in the endoplasmic reticulum (ER). The modified proteins are then transported through the secretory pathway to the cell surface. We have identified two genes inSaccharomyces cerevisiae, LAG1 and a novel gene termed DGT1 (for “delayed GPI-anchored protein transport”), encoding structurally related proteins with multiple membrane-spanning domains. Both proteins are localized to the ER, as demonstrated by immunofluorescence microscopy. Deletion of either gene caused no detectable phenotype, whereas lag1Δ dgt1Δ cells displayed growth defects and a significant delay in ER-to-Golgi transport of GPI-anchored proteins, suggesting thatLAG1 and DGT1 encode functionally redundant or overlapping proteins. The rate of GPI anchor attachment was not affected, nor was the transport rate of several non–GPI-anchored proteins. Consistent with a role of Lag1p and Dgt1p in GPI-anchored protein transport, lag1Δ dgt1Δ cells deposit abnormal, multilayered cell walls. Both proteins have significant sequence similarity to TRAM, a mammalian membrane protein thought to be involved in protein translocation across the ER membrane. In vivo translocation studies, however, did not detect any defects in protein translocation in lag1Δ dgt1Δcells, suggesting that neither yeast gene plays a role in this process. Instead, we propose that Lag1p and Dgt1p facilitate efficient ER-to-Golgi transport of GPI-anchored proteins.

Developmental regulation of cell-surface glycoproteins in clonal cultures of human skeletal muscle satellite cells

1989 ◽  
Vol 67 (2-3) ◽  
pp. 128-136 ◽  
Author(s):  
Shashikant Champaneria ◽  
Paul C. Holland ◽  
George Karpati ◽  
Claude Guérin
Keyword(s):  
Skeletal Muscle ◽  
Cell Surface ◽  
Satellite Cells ◽  
Human Skeletal Muscle ◽  
Developmental Regulation ◽  
Lectin Binding ◽  
Primary Cultures ◽  
Surface Proteins ◽  
Cell Surface Glycoproteins ◽  
Surface Glycoproteins

Pure populations of myogenic cells were obtained by cloning satellite cells from human skeletal muscle biopsies. Cell-surface glycoproteins at various stages of myogenesis were analysed by one- and two-dimensional gel electrophoresis. A total of 14 distinct proteins were detectable at the cell surface, on the basis of their susceptibility to desialation by exogenous neuraminidase or their iodination by exogenous lactoperoxidase. Reproducible changes in lectin binding or iodination of eight of these proteins occurred during myogenesis. Only two of the developmentally regulated proteins were components of the detergent-insoluble extracellular matrix fraction. Developmental regulation of these two proteins was unaffected by growth of cultures in 5-bromo-2′-deoxyuridine to inhibit myogenesis. In contrast, developmental regulation of the other cell-surface proteins was inhibited by growth in 5-bromo-2′-deoxyuridine, suggesting that changes in these proteins are tightly coupled to satellite cell differentiation. These studies represent the first systematic analysis of the surface proteins of pure, clonally derived, primary cultures of normal myogenic cells.Key words: satellite cells, myogenesis, myoblast, glycoproteins, cell surface.

Recognition of collagen by fibroblasts through cell surface glycoproteins reactive with Phaseolus vulgaris agglutinin

1992 ◽  
Vol 101 (3) ◽  
pp. 625-633
Author(s):  
H. Asaga ◽  
K. Yoshizato
Keyword(s):  
Phaseolus Vulgaris ◽  
Cell Surface ◽  
Ricinus Communis ◽  
Specific Binding ◽  
Collagen Gel ◽  
Collagen Fibrils ◽  
Pokeweed Mitogen ◽  
Collagen Gel Contraction ◽  
Cell Surface Glycoproteins ◽  
Surface Glycoproteins

The role of glycochains of cell surface glycoproteins in the cell to collagen interaction was examined by studying the effect of lectins on the fibroblast-mediated collagen gel contraction. Lectins of Phaseolus vulgaris agglutinin (PHA), concanavalin A (ConA), lentil seed agglutinin (LCA), pea agglutinin (PSA), Ricinus communis agglutinin-60 (RCA), and wheat germ agglutinin (WGA) dose-dependently inhibited gel contraction, while lectins of mushroom agglutinin (ABA), peanut agglutinin (PNA), pokeweed mitogen (PWM), and soybean agglutinin (SBA) did not. Of these lectins, PHA seemed to be worthy of further analysis, because PHA, but not other lectins, inhibited spreading of fibroblasts on collagen fibrils but not on plastic or gelatin, suggesting that cell-surface glycoproteins responsive to the lectin are involved in the specific binding of fibroblasts to native collagen fibrils. The inhibitory effect of PHA-E4, an isolectin of PHA, was more intense than that of PHA-L4, another isolectin of PHA. The collagen gel contraction was also inhibited by tunicamycin and monensin in a concentration-dependent and reversible manner. These results strongly suggest that PHA-E4-reactive glycoproteins of the fibroblast surface play an important role in cell to collagen binding during the gel contraction. Five membrane proteins including beta 1 subunits of the integrin family were obtained by affinity chromatography with PHA-E4.

scholarly journals Cell surface oligosaccharides on Dictyostelium during development

1991 ◽  
Vol 99 (3) ◽  
pp. 485-495
Author(s):  
SUPAVADEE AMATAYAKUL-CHANTLER ◽  
MICHAEL A. J. FERGUSON ◽  
RAYMOND A. DWEK ◽  
THOMAS W. RADEMACHER ◽  
RAJ B. PAREKH ◽  
...  
Keyword(s):  
Cell Surface ◽  
Time Frame ◽  
Protein Glycosylation ◽  
Developmental Studies ◽  
Plant Glycoproteins ◽  
Chemical Technique ◽  
Cell Surface Glycoproteins ◽  
Oligosaccharide Structures ◽  
Surface Glycoproteins

Developmental studies of the changes in protein glycosylation are useful in elucidating the role of oligosaccharides in biological events. We have used the chemical technique, hydrazinolysis, to release oligosaccharides from cell surface glycoproteins of Dictyostelium discoideum. Oligomannose type, xylose- and fucose-containing oligosaccharides were found to be present. The charged oligosaccharides contained sulphate and mannose 6-phosphate residues; no sialic acid was detected. The charged oligosaccharides also contained significant amounts of xylose, arabinose, fucose and galactose, as well as mannose and N-acetylglucosamine, which were the main constituents of the neutral glycans. By monitoring the chemical characteristics of the liberated oligosaccharides, dramatic changes in both the charge and size distribution of cell surface oligosaccharides were observed throughout the 24 h period of cell development. A comparison, however, between the neutral glycan structures of prestalk and prespore cells, over the same time frame showed no dramatic differences Discoidin, a lectin present on the cell surface of 8 h cells, was found not to be glycosylated. Affinity chromatography using immobilised discoidin was used to probe a sugar library made from the cell surface glycoproteins of 8h cells. Discoidin was found to bind selectively an oligosaccharide with the structure Manα3(Manα6)(Xylβ2)Manβ4GlcNAc. This oligosaccharide lacks a conventional N,N'-diacetylchitobiose core and has only been previously observed in plant glycoproteins. Peptide-N-glycosidase F treatment of horseradish peroxidase released an identical structure, confirming that the oligosaccharide was not a degradation fragment of the hydrazine. The oligosaccharide was found to inhibit discoidinmediated haemagglutination with a Kt of 0.75 mM, a concentration approximately 100 times lower than that for galactose The correlation between changes in the amoebal plasma membrane oligosaccharide structures and the biological events occurring at different stages of development such as cell-cell adhesion and cellsubstratum attachment suggest an important role for sugars in these processes

Interaction ofVicia gramineaAnti-N Lectin with Cell Surface Glycoproteins from Erythrocytes with Rare Blood Group Antigens

1984 ◽  
Vol 365 (1) ◽  
pp. 469-478 ◽  
Author(s):  
Dominique BLANCHARD ◽  
Alain ASSERAF ◽  
Marie José PRiGENT ◽  
John J. MOULDS ◽  
Dasnayanee CHANDANAYINGYONG ◽  
...  
Keyword(s):  
Cell Surface ◽  
Blood Group ◽  
Blood Group Antigens ◽  
Cell Surface Glycoproteins ◽  
Surface Glycoproteins
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