Glycosylation of CD44 is implicated in CD44-mediated cell adhesion to hyaluronan.
Glycosylation of CD44 is implicated in CD44-mediated cell adhesion to hyaluronan.
复制标题
DOI：
10.1083/jcb.132.6.1199
复制
发表时间：
1996-03
期刊：
影响因子：
--
通讯作者：
Stamenkovic I
中科院分区：
文献类型：
--
作者：
Bartolazzi A;Nocks A;Aruffo A;Spring F;Stamenkovic I
CD 44介导的细胞与透明质酸盐的粘附受机制控制，但机制尚不清楚。在目前的工作中，我们研究了N-连接的糖基化和Ser-Gly基序在调节CD 44-透明质酸相互作用中的作用。我们的研究结果表明，一组人细胞系组成性表达CD 44与N-连接的糖基化衣霉素的抑制剂的治疗结果在这些细胞的附着透明质酸包被的基板的损失。相比之下，用脱氧甘露尻霉素处理相同的细胞，其抑制高甘露糖寡糖转化为复杂的N-连接的碳水化合物，导致CD 44介导的与透明质酸盐的粘附没有变化或增加，这表明复杂的N-连接的寡糖可能不是CD 44-HA相互作用所必需的，甚至可能抑制CD 44-HA相互作用。使用用CD 44 N-连接糖基化位点特异性突变体稳定转染的人黑素瘤细胞，我们表明CD 44的透明质酸识别结构域内的五个潜在N-连接糖基化位点的完整性对于透明质酸结合是至关重要的。这些潜在的N-连接的糖基化位点中的任何一个的突变消除了CD 44介导的黑色素瘤细胞附着到透明质酸包被的表面，这表明所有五个位点对于保持HA识别结构域处于适当的构象是必要的。我们还表明，丝氨酸残基的突变构成的四个Ser-Gly基序在膜近端域，并提供潜在的位点糖胺聚糖侧链连接，损害透明质酸结合。总之，这些观察结果表明，糖基化的CD 44的变化可以有深刻的影响，其与透明质酸的相互作用，并建议，糖基化可能提供一个重要的调节机制的CD 44功能。
CD44-mediated cell adhesion to hyaluronate is controlled by mechanisms which are poorly understood. In the present work we examine the role of N-linked glycosylation and Ser-Gly motifs in regulating CD44- hyaluronate interaction. Our results show that treatment of a panel of human cell lines which constitutively express CD44 with the inhibitor of N-linked glycosylation tunicamycin results in the loss of attachment of these cells to hyaluronate-coated substrate. In contrast, treatment of the same cells with deoxymannojirimycin, which inhibits the conversion of high mannose oligosaccharides to complex N-linked carbohydrates, results in either no change or an increase in CD44- mediated adhesion to hyaluronate, suggesting that complex N-linked oligosaccharides may not be required for and may even inhibit CD44-HA interaction. Using human melanoma cells stably transfected with CD44 N- linked glycosylation site-specific mutants, we show that integrity of five potential N-linked glycosylation sites within the hyaluronate recognition domain of CD44 is critical for hyaluronate binding. Mutation of any one of these potential N-linked glycosylation sites abrogates CD44-mediated melanoma cell attachment to hyaluronate-coated surfaces, suggesting that all five sites are necessary to maintain the HA-recognition domain in the appropriate conformation. We also demonstrate that mutation of serine residues which constitute the four Ser-Gly motifs in the membrane proximal domain, and provide potential sites for glycosaminoglycan side chain attachment, impairs hyaluronate binding. Taken together, these observations indicate that changes in glycosylation of CD44 can have profound effects on its interaction with hyaluronic acid and suggest that glycosylation may provide an important regulatory mechanism of CD44 function.