Hyaluronan bound to CD44 on keratinocytes is displaced by hyaluronan decasaccharides and not hexasaccharides
Hyaluronan bound to CD44 on keratinocytes is displaced by hyaluronan decasaccharides and not hexasaccharides
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DOI：
10.1074/jbc.273.44.28878
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发表时间：
1998-10-30
影响因子：
4.8
通讯作者：
Tammi, M
中科院分区：
文献类型：
--
作者：
Tammi, R;MacCallum, D;Tammi, M
表皮角质形成细胞之间存在丰富的透明质酸。然而，关于它在这些细胞之间有限的细胞外空间中的组织，几乎一无所知。我们使用[H-3]葡萄糖胺和[S-35]硫酸盐的代谢标记和透明质酸特异性生物素化探针来研究透明质酸的代谢及其在大鼠表皮角质形成细胞系单层培养中的定位。透明质酸（约为20 fg/细胞）分布在两个几乎相等的细胞池的顶端和侧壁，或呈斑块状（约为160 fg/细胞）或弥漫性分布。通过与CD44抗体共定位、透明质酸十糖置换以及阻断透明质酸与CD44结合的抗体表明，斑块中的透明质酸与CD44结合。短于10个单糖的透明质酸低聚物无法取代透明质酸，这表明紧密结合需要CD44二聚化或合作相互作用。弥漫性透明质酸池在其生物合成过程中可能与透明质酸合成酶结合。
Abundant hyaluronan is present between epidermal keratinocytes. However, virtually nothing is known regarding its organization in the limited extracellular space between these cells. We have used metabolic labeling with [H-3]glucosamine and [S-35]sulfate and a hyaluronan-specific biotinylated probe to study the metabolism of hyaluronan and its localization in monolayer cultures of a rat epidermal keratinocyte cell line. Hyaluronan (similar to 20 fg/cell) was present on the apical and lateral surfaces of the cells in two nearly equal pools, either in patches (similar to 160/cell) or diffusely spread. The hyaluronan in the patches is bound to CD44 as indicated by co-localization with an antibody to CD44, and by displacement with hyaluronan decasaccharides as well as with an antibody that blocks hyaluronan binding to CD44. The inability of hyaluronan oligomers shorter than 10 monosaccharides to displace hyaluronan suggests that CD44 dimerization or cooperative interactions are required for tight binding. The diffuse hyaluronan pool is likely bound to hyaluronan synthase during its biosynthesis.