Cummings R D, Smith D F
Dept. of Biochemistry and Molecular Biology, Oklahoma Center for Molecular Medicine, University of Oklahoma Health Sciences Center, Oklahoma City 73104.
Bioessays. 1992 Dec;14(12):849-56. doi: 10.1002/bies.950141210.
Protein-carbohydrate interactions have been found to be important in many steps in lymphocyte recirculation and inflammatory responses. A family of carbohydrate-binding proteins or lectins, termed selectins, has been discovered and shown to be involved directly in these processes. The three known selectins, termed L-, E- and P-selectins, have domains homologous to other Ca(2+)-dependent (C-type) lectins. L-selectin is expressed constitutively on lymphocytes, E-selectin is expressed by activated endothelial cells, and P-selectin is expressed by activated platelets and endothelial cells. Here, we review the nature of the carbohydrate determinants in tissues recognized by these selectins. The expression of specific sialylated, fucosylated and sulfated carbohydrates in activated endothelium and high endothelial venules promotes interactions with L-selectin on leukocyte surfaces. In contrast, E- and P-selectins recognize specific carbohydrate determinants related to sialyl Le(x) antigen on neutrophil and monocyte surfaces. The discovery of the selectins has generated excitement among glycoconjugate researchers that other carbohydrate-binding proteins and their cognate ligands will be found to function in regulating many types of cellular interactions.
蛋白质 - 碳水化合物相互作用在淋巴细胞再循环和炎症反应的许多步骤中都很重要。已发现一类碳水化合物结合蛋白或凝集素，称为选择素，它们直接参与这些过程。已知的三种选择素，即L - 选择素、E - 选择素和P - 选择素，具有与其他钙依赖性（C型）凝集素同源的结构域。L - 选择素在淋巴细胞上组成性表达，E - 选择素由活化的内皮细胞表达，P - 选择素由活化的血小板和内皮细胞表达。在此，我们综述这些选择素所识别的组织中碳水化合物决定簇的性质。活化内皮细胞和高内皮微静脉中特定唾液酸化、岩藻糖基化和硫酸化碳水化合物的表达促进了与白细胞表面L - 选择素的相互作用。相反，E - 选择素和P - 选择素识别与中性粒细胞和单核细胞表面唾液酸化路易斯（x）抗原相关的特定碳水化合物决定簇。选择素的发现激发了糖缀合物研究人员的兴趣，他们认为其他碳水化合物结合蛋白及其同源配体将在调节多种细胞相互作用中发挥作用。
