Identification of a specific glycoprotein ligand for P-selectin (CD62) on myeloid cells.
Identification of a specific glycoprotein ligand for P-selectin (CD62) on myeloid cells.
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DOI：
10.1083/jcb.118.2.445
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发表时间：
1992-07
期刊：
影响因子：
--
通讯作者：
McEver RP
中科院分区：
文献类型：
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作者：
Moore KL;Stults NL;Diaz S;Smith DF;Cummings RD;Varki A;McEver RP
P-选择素（CD 62，GMP-140，PADGEM）是活化血小板和内皮细胞上的一种Ca（2+）依赖性凝集素，通过与唾液酸化岩藻糖基化乳糖胺聚糖相互作用，作为骨髓细胞的受体发挥作用。P-选择素结合到髓样细胞上有限数量的蛋白酶敏感位点，但携带P-选择素识别的聚糖的蛋白质是未知的。中性粒细胞或HL-60细胞膜提取物与[125 I] P-选择素的印迹和[3 H]葡糖胺标记的HL-60细胞提取物的亲和层析用于鉴定P-选择素配体。主要配体在非还原条件下约为250，000 M（r），在还原条件下约为120，000。P-选择素与配体的结合是Ca 2+依赖性的，并被P-选择素的mAb阻断。短暂的唾液酸酶消化的配体增加其表观分子量，然而，长期消化废除P-选择素的结合。肽：N-糖苷酶F处理使配体的表观分子量降低约3，000，但不影响P-选择素结合。蛋白质印迹和免疫耗竭实验表明，配体不是lamp-1，lamp-2或L-选择素，它们携带唾液酸Le（x），也不是leukosialin，一种类似分子量的高度唾液酸化的糖蛋白。该配体与P-选择素的优先相互作用表明，它可能在髓样细胞与活化的血小板和内皮细胞的粘附中起作用。
P-selectin (CD62, GMP-140, PADGEM), a Ca(2+)-dependent lectin on activated platelets and endothelium, functions as a receptor for myeloid cells by interacting with sialylated, fucosylated lactosaminoglycans. P-selectin binds to a limited number of protease- sensitive sites on myeloid cells, but the protein(s) that carry the glycans recognized by P-selectin are unknown. Blotting of neutrophil or HL-60 cell membrane extracts with [125I]P-selectin and affinity chromatography of [3H]glucosamine-labeled HL-60 cell extracts were used to identify P-selectin ligands. A major ligand was identified with an approximately 250,000 M(r) under nonreducing conditions and approximately 120,000 under reducing conditions. Binding of P-selectin to the ligand was Ca2+ dependent and was blocked by mAbs to P-selectin. Brief sialidase digestion of the ligand increased its apparent molecular weight; however, prolonged digestion abolished binding of P- selectin. Peptide:N-glycosidase F treatment reduced the apparent molecular weight of the ligand by approximately 3,000 but did not affect P-selectin binding. Western blot and immunodepletion experiments indicated that the ligand was not lamp-1, lamp-2, or L-selectin, which carry sialyl Le(x), nor was it leukosialin, a heavily sialylated glycoprotein of similar molecular weight. The preferential interaction of the ligand with P-selectin suggests that it may play a role in adhesion of myeloid cells to activated platelets and endothelial cells.