Changes in glycoprotein fucosylation in a concanavalin A-resistant variant of a human leukemia cell line (K562)

✍ Scribed by Louise G. Bernier; Arthur K. Sullivan

• Publisher: John Wiley and Sons
• Year: 1988
• Tongue: English
• Weight: 655 KB
• Volume: 37
• Category: Article
• ISSN: 0730-2312
• DOI: 10.1002/jcb.240370207

✦ Synopsis

Previous studies from this and other laboratories have shown that variants of tumor cell lines can be selected for resistance to the lytic action of natural killer (NK) cells. One of these (K562-Clonc I), when made resistant to the toxic effccts of Concanavalin A (Con A-Rl), regained its sensitivity to NK. Comparing the plasma membrdncs of Clone I and Con A-RI , we observed 1) a very similar electrophoretic pattern of membrane glycoproteins identified by binding to the lectins Con A, WGA, PNA, and SBA; 2) an increase in binding of Ulex europaeus lectin to a group of glycoproteins from Con A-Rl that wcre sensitive to treatment with fucosidase and Nglycanasc and that had a diffuse mobility ranging in apparent molecular weight from 30 to 200 kDa; and 3) a marked decrease in binding of an antibody reactive with the lactoncofucopentaose I11 antigen (Lewis x). This constellation of changes is an unusual pattern to follow Con A resistancc and may point to a pathway of glycosylation that a leukemic cell might use to modify its recognition by the NK mechanism.