Adamson E D, Baribault H, Kemler R
La Jolla Cancer Research Foundation, California 92037.
Dev Biol. 1990 Apr;138(2):338-47. doi: 10.1016/0012-1606(90)90201-s.
Uvomorulin (E-cadherin) is a cell adhesive molecule analogous to L-CAM in the chicken. Uvomorulin is important in the process of compaction in eight-cell mouse embryos and plays a role in F9 embryonal carcinoma cell interactions but it is not clear if it mediates aggregation or compaction, the closer interaction that also occurs in F9 cells cultured in suspension. This paper describes the finding of reduced levels of uvomorulin in a mutant cell line of F9 (5.51 att-) that is consistent with a role for uvomorulin in both aggregation and compaction. The mutant line expresses 40-50% of normal levels of uvomorulin as measured by surface radioiodination, immunoblotting, and biosynthetic labeling and immunoprecipitation with two different antisera. The mutant cell line expresses only abnormally unstable uvomorulin transcripts at very low levels. In addition, karyotypic analyses revealed an abnormal chromosome 8 on which the uvomorulin gene is located and therefore could account for aberrant uvomorulin expression. F9 5.51 att- cells aggregate loosely but do not compact (A. Grover, M. J. Rosenstraus, B. Sterman, M. E. Snook, and E. D. Anderson, 1987, Dev. Biol. 119, 1-11). The conclusion is that reduced levels of uvomorulin are sufficient for aggregation but insufficient for compaction.
桥粒芯糖蛋白（E - 钙黏蛋白）是一种细胞黏附分子，类似于鸡体内的L - 钙黏蛋白。桥粒芯糖蛋白在八细胞期小鼠胚胎的紧密化过程中起重要作用，并在F9胚胎癌细胞相互作用中发挥作用，但尚不清楚它是否介导聚集或紧密化，后者是悬浮培养的F9细胞中也会发生的更紧密的相互作用。本文描述了在F9突变细胞系（5.51 att -）中桥粒芯糖蛋白水平降低的发现，这与桥粒芯糖蛋白在聚集和紧密化过程中的作用一致。通过表面放射性碘化、免疫印迹以及用两种不同抗血清进行生物合成标记和免疫沉淀测定，该突变细胞系表达的桥粒芯糖蛋白水平为正常水平的40 - 50%。该突变细胞系仅以极低水平表达异常不稳定的桥粒芯糖蛋白转录本。此外，核型分析显示8号染色体异常，而桥粒芯糖蛋白基因位于该染色体上，因此可以解释桥粒芯糖蛋白表达异常。F9 5.51 att -细胞松散聚集但不紧密化（A. 格罗弗、M. J. 罗森施特劳斯、B. 斯特曼、M. E. 斯诺克和E. D. 安德森，1987年，《发育生物学》119卷，第1 - 11页）。结论是桥粒芯糖蛋白水平降低足以实现聚集，但不足以实现紧密化。
