Tyrosine sulfation enhances but is not required for PSGL-1 rolling adhesion on P-selectin.
Tyrosine sulfation enhances but is not required for PSGL-1 rolling adhesion on P-selectin.
复制标题
酪氨酸硫酸化可增强 PSGL-1 在 P-选择素上的滚动粘附，但不是必需的。
DOI：
10.1016/s0006-3495(01)75850-x
复制
发表时间：
2001
影响因子：
3.4
通讯作者：
Hammer,DA
中科院分区：
文献类型：
--
作者：
Rodgers,SD;Camphausen,RT;Hammer,DA
P-选择素糖蛋白配体-1(PSGL-1)是一种大分子(240 KDa)糖蛋白，存在于几乎所有的白细胞表面。成熟的分子被多个N-和O-连接的糖链装饰，并显示四糖唾液酸路易斯X(SLeX)的副本，以及加工蛋白质的N-末端附近的三个酪氨酸硫酸酯(Tyr-SO3)基团。以前的研究表明，PSGL-1除了需要用SLeX糖基化外，还需要酪氨酸磺化，才能成功地与P-选择素相互作用。为了更好地了解PSGL-1配体的生化特征与其黏附表型的关系，我们测量了一系列定义明确的PSGL-1变体在其生化修饰方面不同的流动下对P-和E-选择素涂层底物的黏附动力学。这些变异体是不同的PSGL-1多肽：一个含有sLeXin和三个N-末端Tyr-SO3基团(SGP3)，一个具有不含酪氨酸硫酸盐的sLeX(GP1)，以及一个没有sLeX但有三个N-末端Tyr-SO3基团(SP3)。虽然所有表达SLeX和/或Tyr-SO3的多肽都支持某种形式的滚动黏附在P-选择素上，但只有表达sLeX基团的多肽在E-选择素上表现出滚动黏附。在P-选择素上，PSGL-1多肽的黏附强度依次为SGP3>；GP1>；SP3。在P-选择素上强健的滚动粘附力是由GP1多肽介导的，尽管它缺乏酪氨酸硫酸盐。然而，在糖基化多肽(SGP3)中添加酪氨酸硫酸盐为P-选择素创造了一种超级配体，它支持在所有剪切速率下较慢的滚动粘附性，并支持在高得多的剪切速率下的滚动粘附性。酪氨酸的硫化对PSGL-1在E-选择素上的滚动没有类似的影响。滚动动力学中的这种功能差异是通过无细胞系统唯一实现的，该系统允许精确、明确地识别粘连配体的功能活性。这些发现与最近发表的这些多肽与E-和P-选择素相互作用的结构和功能特征是一致的。
P-selectin glycoprotein ligand-1 (PSGL-1) is a large (240 kDa) glycoprotein found on the surface of nearly all leukocytes. The mature molecule is decorated with multiple N- and O-linked glycans and displays copies of the tetrasaccharide sialyl-Lewisx(sLeX), as well as a cluster of three tyrosine sulfate (tyr-SO3) groups near the N-terminus of the processed protein. Previous studies have suggested that PSGL-1 needs to be tyrosine-sulfated, in addition to glycosylated with sLeX, to successfully interact with P-selectin. To better understand how biochemical features of the PSGL-1 ligand are related to its adhesion phenotype, we have measured the dynamics of adhesion under flow of a series of well-defined PSGL-1 variants that differ in their biochemical modification, to both P- and E-selectin-coated substrates. These variants are distinct PSGL-1 peptides: one that possesses sLeXin conjunction with three N-terminal tyr-SO3groups (SGP3), one that possesses sLeXwithout tyrosine sulfation (GP1), and one that lacks sLeXbut has three N-terminal tyr-SO3groups (SP3). Although all peptides expressing sLeX, tyr-SO3, or both supported some form of rolling adhesion on P-selectin, only peptides expressing sLeXgroups showed rolling adhesion on E-selectin. On P-selectin, the PSGL-1 peptides demonstrated a decreasing strength of adhesion in the following order: SGP3>GP1>SP3. Robust, rolling adhesion on P-selectin was mediated by the GP1 peptide, despite its lack of tyrosine sulfation. However, the addition of tyrosine sulfation to glycosylated peptides (SGP3) creates a super ligand for P-selectin that supports slower rolling adhesion at all shear rates and supports rolling adhesion at much higher shear rates. Tyrosine sulfation has no similar effect on PSGL-1 rolling on E-selectin. Such functional distinctions in rolling dynamics are uniquely realized with a cell-free system, which permits precise, unambiguous identification of the functional activity of adhesive ligands. These findings are consistent with structural and functional characterizations of the interactions between these peptides and E- and P-selectin published recently.