Analysis of cell surface galactosyltransferase activity during mouse trophectodermal differentiation.
Analysis of cell surface galactosyltransferase activity during mouse trophectodermal differentiation.
复制标题
小鼠滋养外胚层分化过程中细胞表面半乳糖基转移酶活性的分析。
DOI：
10.1016/0012-1606(89)90107-3
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发表时间：
1989
影响因子：
2.7
通讯作者：
Babiarz,BS
中科院分区：
文献类型：
--
作者：
Hathaway,HJ;Romagnano,LC;Babiarz,BS
第7.5天小鼠胚胎的外胎盘锥（EPC）由粘附的、增殖的滋养层细胞组成，这些滋养层细胞在植入期间转化为侵袭性滋养层巨细胞。粘附性滋养层细胞类型在细胞表面表达单克隆确定的乳糖胺聚糖（LAG）;转化为巨细胞导致LAG细胞表面表达的丧失（H.海瑟薇和B。S. Babiarz，1988，Cell Differ.24，55 -66）。LAG可以作为细胞表面半乳糖基转移酶（GalTase）的底物，在许多不同的细胞类型之间提供粘附机制（B. D. Shur，1984，Mol. Cell. 61，143 -158）。假设EPC中的LAG代表类似GalTase介导的细胞：细胞粘附系统的底物。通过掺入外源性放射性标记底物的半乳糖，在发育第7.5天的EPC滋养层上证明了细胞表面GalTase活性。在24至48小时EPC滋养层培养的酶被定位的免疫荧光细胞：细胞接触的地区。单层分化的滋养层巨细胞缺乏这种标记模式。GalTase的细胞表面糖肽底物洗脱为单峰，表观分子量为15，000 Da。该物质的一部分对内切-β-半乳糖苷酶消化敏感，表明其含有LAG结构。在24至48小时EPC副产物中，用α-乳白蛋白、尿苷5′-二磷酸半乳糖或抗GalTase抗体干扰酶：底物复合物，导致细胞：细胞接触破坏。滋养层巨细胞的分化导致对表面GalTase扰动的敏感性丧失。结果表明，粘附EPC滋养层细胞具有半乳糖苷酶介导的细胞：细胞粘附系统，其在分化为侵袭性滋养层巨细胞后下调。
The ectoplacental cone (EPC) of the Day 7.5 mouse embryo consists of a core of adhesive, proliferating trophoblast cells which transform to invasive trophoblast giant cells during implantation. Adhesive trophoblast cell types express monoclonally defined lactosaminoglycans (LAGs) at the cell surface; transformation to giant cells results in a loss of LAG cell surface expression (H. J. Hathaway and B. S. Babiarz, 1988,Cell Differ.24,55–66). LAGs can serve as substrates for cell surface galactosyltransferase (GalTase), providing an adhesive mechanism between a number of different cell types (B. D. Shur, 1984,Mol. Cell. Biochem.61,143–158). It was hypothesized that the LAGs in the EPC represented a substrate for a similar GalTase-mediated cell:cell adhesion system. Cell surface GalTase activity was demonstrated on EPC trophoblast on Day 7.5 of development by the incorporation of galactose from exogenous radiolabeled substrate. In 24- to 48-hr EPC trophoblast cultures the enzyme was localized by immunofluorescence to areas of cell:cell contact. Monolayers of differentiated trophoblast giant cells lacked this labeling pattern. The cell surface glycopeptide substrate for GalTase eluted as a single peak with an apparent molecular mass of 15,000 Da. A portion of this material was sensitive to endo-β-galactosidase digestion, indicating that it contained a LAG structure. Perturbation of the enzyme:substrate complex in 24- to 48-hr EPC outgrowths, with α-lactalbumin, uridine 5′-diphosphogalactose, or anti-GalTase antibody, resulted in the disruption of cell:cell contacts. Differentiation to trophoblast giant cells resulted in a loss of sensitivity to surface GalTase perturbation. The results suggest that adhesive EPC trophoblast cells possess a GalTase-mediated cell:cell adhesion system which is downregulated upon differentiation to invasive trophoblast giant cells.