Lanoix J, Skup D, Collard J F, Raymond Y
Institut du cancer de Montréal, Hôpital Notre-Dame, Québec, Canada.
Biochem Biophys Res Commun. 1992 Dec 30;189(3):1639-44. doi: 10.1016/0006-291x(92)90265-m.
The polypeptide composition of the nuclear lamina can display important variations: undifferentiated cells express only lamin B and they acquire lamins A and C only after differentiation. We have analyzed the expression of lamins A and C in P19 pluripotent mouse embryonal carcinoma cells. Undifferentiated P19 cells are completely devoid of lamins A and C. We show that undifferentiated P19 cells contain low, but detectable steady-state levels of RNAs for lamins A and C that begin to increase by 24 h of retinoic acid-induced differentiation. However, the rate of transcription of the lamin A and C gene(s), analyzed by run-on transcription assays, remains unchanged during the differentiation process. These results demonstrate that, at least in P19 embryonal carcinoma cells, regulation of the expression of lamins A and C is a post-transcriptional event.
未分化细胞仅表达核纤层蛋白B，只有在分化后才会获得核纤层蛋白A和C。我们分析了核纤层蛋白A和C在P19多能小鼠胚胎癌细胞中的表达情况。未分化的P19细胞完全缺乏核纤层蛋白A和C。我们发现，未分化的P19细胞含有低水平但可检测到的核纤层蛋白A和C的RNA稳态水平，在视黄酸诱导分化24小时后开始增加。然而，通过连续转录分析检测的核纤层蛋白A和C基因的转录速率在分化过程中保持不变。这些结果表明，至少在P19胚胎癌细胞中，核纤层蛋白A和C表达的调控是一个转录后事件。
