Laminin induces the stable expression of surface galactosyltransferase on lamellipodia of migrating cells.
Laminin induces the stable expression of surface galactosyltransferase on lamellipodia of migrating cells.
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DOI：
10.1083/jcb.108.6.2507
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发表时间：
1989-06
期刊：
影响因子：
--
通讯作者：
Shur BD
中科院分区：
文献类型：
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作者：
Eckstein DJ;Shur BD
我们以前已经表明，细胞表面半乳糖基转移酶（GalTase）介导的细胞扩散和迁移的基底层基质结合层粘连蛋白内的N-连接的寡糖底物。在这项研究中，我们研究了细胞表面GalTase的分布和表达过程中的间充质细胞迁移的各种细胞外基质。针对亲和纯化的β 1，4 GalTase以及抗GalTase Fab片段的抗血清抑制了含层粘连蛋白基质上的细胞迁移，而在相同条件下，抗GalTase IgG对纤连蛋白底物上的细胞迁移率没有影响。细胞迁移层粘连蛋白的表面GalTase的水平，测定125 I-抗体结合和直接酶测定，比类似的细胞迁移纤连蛋白的三倍。另一方面，当细胞在层粘连蛋白或纤连蛋白上生长时，通过酶法或北方印迹分析测定的总细胞GalTase相似。层粘连蛋白依赖性增加表面GalTase是由于其表达到迁移细胞的前缘和后缘与肌动蛋白的微丝双标记间接免疫荧光测定。在静止的细胞上，表面GalTase水平较低，但随着细胞开始在层粘连蛋白上迁移，GalTase变得极化为生长中的片状伪足。当细胞迁移到纤连蛋白底物上时，在板状伪足或丝状伪足上检测不到半乳糖苷酶。这些结果表明，含层粘连蛋白的基质诱导GalTase在细胞板状伪足和丝状伪足上稳定表达，在那里它介导随后的细胞铺展和迁移。由于纤连蛋白不能诱导半乳糖苷酶表达到板状伪足上，这些研究还表明，细胞外基质可以选择性地影响哪些细胞内组分维持在细胞表面上。
We have previously shown that cell surface galactosyltransferase (GalTase) mediates cell spreading and migration on basal lamina matrices by binding N-linked oligosaccharide substrates within laminin. In this study we have examined the distribution and expression of cell surface GalTase during mesenchymal cell migration on various extracellular matrices. Antisera raised against affinity-purified beta 1,4 GalTase, as well as anti-GalTase Fab fragments, inhibited cell migration on laminin-containing matrices, whereas under identical conditions, anti-GalTase IgG had no effect on the rate of cell migration on fibronectin substrates. Cells migrating on laminin had three times the level of surface GalTase, assayed by 125I-antibody binding and by direct enzyme assay, than similar cells migrating on fibronectin. On the other hand, total cellular GalTase, assayed either enzymatically or by Northern blot analysis, was similar when cells were grown on laminin or fibronectin. The laminin-dependent increase in surface GalTase was due to its expression onto the leading and trailing edges of migrating cells in association with actin-containing microfilaments assayed by double-label indirect immunofluorescence. On stationary cells, surface GalTase levels were low, but as cells began to migrate on laminin GalTase became polarized to the growing lamellipodia. GalTase was not detectable on lamellipodia or filopodia when cells migrated on fibronectin substrates. These results show that laminin-containing matrices induce the stable expression of GalTase onto cell lamellipodia and filopodia where it mediates subsequent cell spreading and migration. Since fibronectin was unable to induce GalTase expression onto lamellipodia, these studies also suggest that the extracellular matrix can selectively influence which intracellular components are maintained on the cell surface.