Metabolism of a transformation-sensitive amino acid fucoside in normal and simian virus 40-transformed human embryonic lung cells.
We have demonstrated previously that there is a marked decrease in the level of labeled fucose incorporated into an amino acid fucoside, i.e., fucosyl-N-acetylglucosaminylasparagine (FL4c) in SV40-transformed human embryonic lung cells (SV40-WI-38) as compared to WI-38 cells (Morton, P.A., Klinger, M. M., and Steiner, S. Cancer Res., 42: 3022-3027, 1982). In the current study, we have observed that the reduction in labeled fucose incorporated into FL4c in the SV40-WI-38 cells is paralleled by reduced chemical quantity of that component. [3H]-Fucose pulse/chase and long-term fucose labeling/chase studies, in some instances in the presence of tunicamycin, have revealed that FL4c is a relatively stable end produce of N-linked-type glycoprotein metabolism. The relative metabolic stability argues against breakdown of FL4c as the basis for the markedly reduced level in the SV40-WI-38 cells. However, the transformed cells manifested an almost 3-fold higher level of alpha-L-fucosidase activity when p-nitrophenyl-alpha-fucoside was used as substrate. These results raise the possibility that the parent glycoprotein of FL4c might be more rapidly catabolized in the SV40-WI-38 cells than in the WI-38 cells. Whatever the biochemical basis for the decrease in level of FL4c in transformed human cells, it would seem to underlie a difference between normal and transformed cells in membrane glycoprotein catabolism.
D001216:Asparagine / Q000031:analogs & derivatives* / Q000096:biosynthesis / Q000378:metabolism; D002460:Cell Line; D002471:Cell Transformation, Neoplastic; D005643:Fucose / Q000031:analogs & derivatives* / Q000096:biosynthesis / Q000378:metabolism; D006801:Humans; D007700:Kinetics; D008168:Lung / Q000196:embryology; D013539:Simian virus 40 / Q000235:genetics*; D014316:Tritium; D005644:alpha-L-Fucosidase / Q000032:analysis
D014316:Tritium; D005643:Fucose; C042806:fucosyl-N-acetylglucosaminylasparagine; D001216:Asparagine; D005644:alpha-L-Fucosidase