Atypical mannolipids characterize Thy-1-negative lymphoma mutants.
Essentially all eukaryotic cells, including murine lymphomas, express surface proteins, such as Thy-1, which are anchored by a phosphoinositol mannolipid. Putative mannolipid anchor precursors can be detected in these cells. Six distinct Thy-1-negative lymphoma mutants lack complete mannolipids, and three mutants synthesize atypical mannolipids. The absence of complete mannolipids can account for the lack of expression of multiple mannolipid-anchored proteins and may also account for the lack of lipid anchoring in the human disease paroxysmal nocturnal hemoglobinuria. Structural information on the mannolipids of wild-type and mutant cells indicates that anchor biosynthesis in these cells may involve both transmembrane flip-flop of intermediates and a deacylation step.
Institute of Pathology, Case Western Reserve University, Cleveland, Ohio 44106.
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P
Lemansky
D K
DK
Gupta
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S
Meyale
G
G
Tucker
A M
AM
Tartakoff
D000818:Animals; D000954:Antigens, Surface / Q000235:genetics*; D002240:Carbohydrate Sequence; D002460:Cell Line; D006017:Glycolipids / Q000096:biosynthesis* / Q000302:isolation & purification / Q000378:metabolism; D017261:Glycosylphosphatidylinositols; D008223:Lymphoma / Q000235:genetics* / Q000276:immunology; D008358:Mannose / Q000302:isolation & purification / Q000378:metabolism; D051379:Mice; D008969:Molecular Sequence Data; D009154:Mutation; D010641:Phenotype; D010716:Phosphatidylinositols / Q000378:metabolism; D018800:Thy-1 Antigens
D000954:Antigens, Surface; D006017:Glycolipids; D017261:Glycosylphosphatidylinositols; D010716:Phosphatidylinositols; D018800:Thy-1 Antigens; D008358:Mannose