Turnover of Cellular Carbohydrates in Normal and Rous Sarcoma Virus transformed Cells1 (original) (raw)
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Turnover of cellular carbohydrates in normal and Rous sarcoma virus-transformed cells
PubMed, 1978
We have analyzed the distribution of glucosamine-labeled polymers on the cell surface, in the growth medium, and inside the cell and the net turnover of these polymers during the process of malignant transformation of chick embryo fibroblasts by Rous sarcoma virus. The distribution of label and the turnover kinetics for hyaluronic acid, total glycoproteins, and chondroitins were found to be identical in both normal and transforming cultures. We conclude that nonspecific degradative processes are probably not involved in causing transformation-related alterations in cell surface carbohydrates, althougn degradation of specific macromolecules is not excluded.
Biochimica et Biophysica …, 1992
We measured the lateral diffusion of the fluorescent lipid ar~:~ogue dioctadeeylindocarbocyanine iodide (Dill and of ~x embranc glycoproteins labeled with tetramethylrhodamine (TRITC) ~,cr, inyl concanavalin A (SConA) via fluoicsec, nce photc, blcacbing recovery (FPR) at selected times during a temperatare dowr~shdt experiment on transformation-defective temperature sensitive (td-t.0 Rous sarcoma virus (RSV) NY68-transformed chicken embryo fibroblasts (CEF) and on identically treated CEF and RSV-transformed CEF. There were no significant differences in the later'at diffusion of Dil at any of the times measut,~.d. The lateral diffusion of TRITC-SConA on the RSV-transformed CEF, (1.32 :t: 0.12)' 10-n) cm: s-i was approximately tw:~ times faster than that observed in normal CEF, (0.61 :[:0.06). 10-") cm 2 s-i. in the cells undergoing RSV NY68-mvdiated transformation, TRITC-SConA diffusion increased over a 24-h period frt)m a value comparable to that observed in norma~ CEF, (0.72 + 0.13). 10-n) cm 2 s-I to a value comparable to the RSV-CEF transformed cells, (I.74-.t:0.20)" 10-u) cm 2 s-i. All diffusion measurements reported we,'e made at the permissive temperature tbr RSV-NY68 (35°C) unless stated otherwise. The changes in tile lateral diffusion of TRITC-SConA occurred between the fifth and twelfth hour of the downshift course and could be associated with cytoskcletal disruption and/or fibronectin degradation, both known to occur at this time in RSV-transformcd cells. To assess the contribution of ¢xtraccllular matrix (ECM) degradation, SConA mobility was measured in normal and RSV-transformed cells treated with tryp.,iir. This treatment increased SConA mobility approximately 4-fold in the normal cells relative to untreated controls and only 24old in the RSV-CEF transformed cells. No significant difference in SCoriA mcbility between trypsinized spherical normal and transformed cells was apparent.
The Journal of Cell Biology, 1976
Mouse 3T3 cells and their Simian Virus 40-transformed derivatives (3T3SV) were used to assess the relationship of transformation, cell density, and growth control to the cellular distribution of newly synthesized glycosaminoglycan (GAG). Glucosamine-and galactosamine-containing GAG were labeled equivalently by [all]glucose regardless of culture type, allowing incorporation into the various GAG to be compared under all conditions studied. Three components of each culture type were examined: the cells, which contain the bulk of newly synthesized GAG and are enriched in chondroitin sulfate and heparan sulfate; cell surface materials released by trypsin, which contain predominantly hyaluronic acid; and the media, which contain predominantly hyaluronic acid and undersulfated chondroitin sulfate.
The Biochemical journal, 1982
1. Heparan sulphates from normal 3T3 fibroblasts are association-prone as indicated by their affinity for agarose gels substituted with cognate heparan sulphate species. Heparan sulphates from SV40-transformed or polyoma-virus-transformed cells have no affinity for the same gels. 2. Heparan sulphates from the medium, the pericellular and intracellular pools of normal, SV40-transformed and polyoma-transformed 3T3 cells were separated into four subfractions (HS1-HS4) by ion-exchange chromatography. In general, HS1-HS3 were found in cell-derived heparan sulphates, whereas HS3-HS4 were present in the medium. The heparan sulphates from transformed cells were more heterogeneous and of lower charge density than those from the normal counterpart. 3. Degradations via periodate oxidation/alkaline elimination yielded the oligomers glucosamine-(hexuronate-glucosamine)(n)-R with n=1-5 and a large proportion of N-sulphate groups. There was a large contribution of fragments n=4-5 from heparan sulp...
Proceedings of the National Academy of Sciences, 1976
The glycoproteins of whole cells have been analyzed by direct application of radio-iodinated lectins to sodium dodecyl sulfate gels, followed by autoradiography. By use of lectins with different carbohydrate specificities, different sets of glycoproteins have been visualized. The most prominent lectin-binding band in many gels is the large, external, transformation-sensitive (LETS) protein. Major glycoprotein differences are revealed when normal and virus-transformed cells are compared. Certain differences, however, are also seen when the glycoproteins are compared from two separately derived simian
Determinants of glycolytic rate in normal and transformed chick embryo fibroblasts
Cancer research, 1978
We have investigated the increased rate of glycolysis following transformation of chick embryo fibroblasts by Rous sarcoma virus. In both normal and transformed cells the regeneration of adenosine 5 -diphosphate and orthophosphate was found to be the rate-limiting factor for glycolysis. The plasma membrane Na -K -adenosine-5 -triphosphatase (ATPase) was a major contributor to adenosine 5 -diphosphate and orthophosphate regenera tion in the fibroblasts, but its contribution was not changed by viral transformation. Neither protein synthe sis, nor nucleic acid synthesis, nor microtubular function contributed significantly to the adenosine 5 -diphosphate and orthophosphate pools required for glycolysis either before or after transformation. Measurements of oxidative phospnorylation and of ATPase activity of isolated mito chondria did not reveal any changes following transfor mation that could account for the increased rate of glycol ysis. We propose that an ATPase, which is not sensitive to conventional inhibitors of the Na -K -ATPase or mito chondria! ATPase, appears or is increased after transfor mation.
Membrane glycopeptides from subcellular fractions of control and virus-transformed cells
The Journal of biological chemistry, 1974
The glycopeptides from various subcellular fractions isolated from control, BHK2r/C13, and virus-transformed C13/ BI baby hamster kidney cells have been compared by chromatography on columns of Sephadex G-50 in order to determine (a) whether changes in cell surface glycoproteins previously shown to occur upon viral transformation are also found in the glycoproteins of membranes associated with other subcellular membrane fractions and (b) whether the glycopeptides associated with the subcellular fractions were similar to those found on the surface membrane. Cells were grown in the presence of D-["Cl-or [3H]glucosamine or' L-['~C]-or [aH]fucose. Fractions to be compared were mixed and digested with pronase, and the glycopeptides were fractionated by gel filtration. These studies showed that the alterations accompanying transformation seen in the surface membrane glycopeptides were also found in other subcellular fractions. These alterations consist of as marked increase in the amount of higher molecular weight material in the transformed cell. Neuraminidase treatment of this material diminishes or eliminates the diEerence between the normal and malignant patterns. The relative distribution of glycopeptides in the mitochondrial, nuclear, and rough endoplasmic reticular fractions differed in some respects from that of the surface membrane. Glycopeptides associated with the subcellular fractions were not due to contamination by surface membranes.