Involvement of a 40-kDa glycoprotein in food recognition, prey capture, and induction of phagocytosis in the protozoon Actinophrys sol.
Involvement of a 40-kDa glycoprotein in food recognition, prey capture, and induction of phagocytosis in the protozoon Actinophrys sol.
复制标题
40 kDa 糖蛋白参与原生动物 Actinophrys sol 中的食物识别、猎物捕获和诱导吞噬作用。
作者：
M. Sakaguchi;H. Murakami;T. Suzaki
一种40 kda的糖蛋白（gp40）被鉴定为一种与Con - A结合的粘着物质，用于固定和摄取猎物鞭毛虫。gp40的分离和部分鉴定表明：1)gp40是放线菌的主要Con - a结合蛋白，分子量为40 kDa，储存在分泌颗粒中，称为外泌体；2)通过Con a亲和层析纯化gp40，确定其n端氨基酸序列为H2N-KVLK-FEDDFDTFDLQ；3)猎物鞭毛粘附在gp40固定的琼脂糖珠上；4) gp40固定化琼脂糖珠诱导放线菌吞噬；5)可溶性gp40诱导外殖体的胞吐和卵泡体的细胞融合。这些结果表明，gp40是放线素细胞的一种多功能分泌蛋白，在对食物生物的正确靶向和自我识别中都是必需的。
A 40-kDa glycoprotein (gp40) was identified as a Con A-binding adhesive substance of the heliozoon Actinophrys sol for immobilizing and ingesting prey flagellates. Isolation and partial characterization of gp40 showed that: 1) gp40 is a major Con A-binding protein of Actinophrys with a molecular weight of 40 kDa, and is stored in secretory granules called extrusomes; 2) gp40 was purified by Con A-affinity chromatography, and the N-terminal amino acid sequence was determined as H2N-KVLK-FEDDFDTFDLQ; 3) prey flagellates became adhered to gp40-immobilized agarose beads; 4) phagocytosis of Actinophrys was induced against gp40-immobilized agarose beads; and 5) solubilized gp40 induced exocytosis of extrusomes and cell fusion of heliozoons. These results indicate that gp40 is a multi-functional secretory protein of Actinophrys, which is required in correct targeting of the heliozoon to food organisms as well as in self-recognition.