Effect of ras-activation on the expression of glycosyl-phosphatidylinositol-anchored proteins on the plasma membrane.
NIH3T3 cells were transfected with a vector containing c-H-ras under the transcriptional control of the mouse metallothionein-I promoter. When c-H-ras expression was induced with heavy metal ions there was a marked reduction in the expression of two glycosylphosphatidylinositol (GPI) anchored proteins, TAP/Ly-6A.2 and Thy-1, on the plasma membrane of the transformed cells. In contrast the cell-surface expression of other non-GPI-anchored proteins was unaltered. The major loss of Thy-1 induced by ras activation occurred from the pool of molecules expressed on the cell surface. The Thy-1 molecules that were preferentially lost from the surface of the ras-transformed cells could not be recovered from the extracellular fluid by immunoprecipitation. In contrast, the rate of internalization of Thy-1 was increased approximately 69% subsequent to ras activation. The possible significance of these findings to the function of c-H-ras is discussed.
Harvard Medical School, Department of Pathology, Boston, Massachusetts.
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Bamezai
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KL
Rock
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D000945:Antigens, Differentiation, T-Lymphocyte / Q000235:genetics / Q000378:metabolism*; D000954:Antigens, Surface / Q000235:genetics / Q000378:metabolism*; D015152:Blotting, Northern; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism / Q000648:ultrastructure; D004591:Electrophoresis, Polyacrylamide Gel; D005347:Fibroblasts / Q000378:metabolism* / Q000648:ultrastructure; D005455:Fluorescent Antibody Technique; D005786:Gene Expression Regulation / Q000502:physiology*; D011905:Genes, ras / Q000235:genetics* / Q000502:physiology; D006017:Glycolipids / Q000378:metabolism*; D017261:Glycosylphosphatidylinositols; D008668:Metallothionein / Q000235:genetics / Q000502:physiology; D051379:Mice; D010716:Phosphatidylinositols / Q000378:metabolism*; D011233:Precipitin Tests; D011401:Promoter Regions, Genetic / Q000235:genetics / Q000502:physiology; D016283:Proto-Oncogene Proteins p21(ras) / Q000235:genetics / Q000502:physiology; D018800:Thy-1 Antigens; D014158:Transcription, Genetic; D018127:Tumor Necrosis Factor Receptor Superfamily, Member 7
D000911:Antibodies, Monoclonal; D000945:Antigens, Differentiation, T-Lymphocyte; D000954:Antigens, Surface; D006017:Glycolipids; D017261:Glycosylphosphatidylinositols; D010716:Phosphatidylinositols; D018800:Thy-1 Antigens; D018127:Tumor Necrosis Factor Receptor Superfamily, Member 7; D008668:Metallothionein; D016283:Proto-Oncogene Proteins p21(ras)