Murine T lymphocytes and T-lymphoma cells produce chondroitin sulphate and heparan sulphate proteoglycans and free heparan sulphate glycosaminoglycan.
Normal murine splenic T lymphocytes and T-lymphoma cells were incubated with [35S]sulphate in low-sulphate medium for 4 hr. Gel filtration and SDS-PAGE revealed that the radiolabelled macromolecules secreted by these cells were almost exclusively chondroitin sulphate and heparan sulphate proteoglycans of relatively low molecular weight (MW), 100,000-200,000. Triton X-100 extracts of the cells contained similar proteoglycans. Under the conditions employed the incorporation of radiolabel by cells grown in vivo was equally distributed between cell-retained and secreted fractions, whereas cells grown in vitro retained some 75% of incorporated label. In general heparan sulphate predominated over chondroitin sulphate in both secreted and cell-retained fractions. Cell extracts also contained a minor proportion of free glycosaminoglycan, which is almost exclusively heparan sulphate. These chains, like those incorporated into the proteoglycan, were around 12,000 MW. The T-lymphoma cells RDM-4, whether grown in vitro or in vivo, also incorporated a substantial proportion of [35S]sulphate into a single, cell-retained protein, 100,000 MW. No such radiolabelled protein was detectable in T cells.
Wilson
A P
AP
Department of Biochemistry, Royal Holloway and Bedford New College, Surrey, U.K.
Rider
C C
CC
D000818:Animals; D002460:Cell Line; D002478:Cells, Cultured; D011508:Chondroitin Sulfate Proteoglycans / Q000096:biosynthesis*; D002809:Chondroitin Sulfates / Q000096:biosynthesis*; D002847:Chromatography, Agarose; D004591:Electrophoresis, Polyacrylamide Gel; D006025:Glycosaminoglycans / Q000096:biosynthesis*; D019812:Heparan Sulfate Proteoglycans; D006497:Heparan Sulfate / Q000096:biosynthesis*; D008223:Lymphoma / Q000378:metabolism*; D051379:Mice; D008806:Mice, Inbred AKR; D008809:Mice, Inbred C3H; D013154:Spleen / Q000276:immunology; D013601:T-Lymphocytes / Q000378:metabolism*
D011508:Chondroitin Sulfate Proteoglycans; D002809:Chondroitin Sulfates; D006025:Glycosaminoglycans; D019812:Heparan Sulfate Proteoglycans; D006497:Heparan Sulfate