Couchman J R, Austria R, Woods A, Hughes R C
Department of Medicine, University of Alabama, Birmingham 35294.
J Cell Physiol. 1988 Aug;136(2):226-36. doi: 10.1002/jcp.1041360204.
In the light of accumulating data that implicate cell surface heparan sulfate proteoglycans (HSPGs) with a role in cell interactions with extracellular matrix molecules such as fibronectin, we have compared the properties of these molecules in wild-type BHK cells and an adhesion-defective ricin-resistant mutant (RicR14). Our results showed that the mutant, unlike BHK cells, cannot form focal adhesions when adherent to planar substrates in the presence of serum. Furthermore, while both cell lines possess similar amounts of cell surface HSPG with hydrophobic properties, that of RicR14 cells had decreased sulfation, reduced affinity for fibronectin and decreased half-life on the cell surface when compared to the normal counterpart. Our conclusions based on this data are that these altered properties may, in part, account for the adhesion defect in the ricin-resistant mutant. Whether this results from the known alteration in assembly of N-linked glycans affecting the carbohydrate chains on the proteoglycan or some other combination of factors is discussed.
鉴于越来越多的数据表明细胞表面硫酸乙酰肝素蛋白聚糖（HSPGs）在细胞与细胞外基质分子（如纤连蛋白）的相互作用中发挥作用，我们比较了野生型BHK细胞和一种黏附缺陷型蓖麻毒素抗性突变体（RicR14）中这些分子的特性。我们的结果表明，与BHK细胞不同，该突变体在血清存在的情况下贴附于平面基质时不能形成黏着斑。此外，虽然两种细胞系都拥有相似数量的具有疏水特性的细胞表面HSPG，但与正常细胞相比，RicR14细胞的HSPG硫酸化程度降低，对纤连蛋白的亲和力降低，在细胞表面的半衰期缩短。基于这些数据我们得出的结论是，这些改变的特性可能部分解释了蓖麻毒素抗性突变体中的黏附缺陷。文中讨论了这是否是由于已知的N-连接聚糖组装改变影响了蛋白聚糖上的糖链，还是其他一些因素的组合所致。
