Logan T J, Jordan K L, Hall D
Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, Pennsylvania 19107.
Mol Biol Cell. 1994 Jun;5(6):667-78. doi: 10.1091/mbc.5.6.667.
To gain an understanding of the role the E2F1 transcription factor plays in cell physiology, the full length protein (E2F1) and an amino terminal deletion of 87 amino acids (E2F1d87) were constitutively expressed in NIH3T3 fibroblasts. Multiple cell lines were generated for each construct. These cells do not proliferate in media containing low serum and do not proliferate in soft agar, indicating that they are likely not transformed. However, both sets of cell lines show increased DNA synthesis and increased numbers of cells in S phase when cultured in media containing low serum, compared to the control cell lines. Cells expressing E2F1d87 (but not E2F1) have an extremely rounded morphology when cultured in 10% serum-containing media. These rounded cells lack detectable microfilaments, microtubules, and focal contacts. However, when these cells are cultured in low serum-containing media (0.5%), they attain the flattened morphology and cytoskeletal structure of normal NIH3T3 cells.
为了了解E2F1转录因子在细胞生理学中的作用，在NIH3T3成纤维细胞中组成性表达了全长蛋白（E2F1）和一个缺失87个氨基酸的氨基末端（E2F1d87）。针对每个构建体产生了多个细胞系。这些细胞在含有低血清的培养基中不增殖，在软琼脂中也不增殖，这表明它们可能未发生转化。然而，与对照细胞系相比，当在含有低血清的培养基中培养时，这两组细胞系均显示出DNA合成增加以及S期细胞数量增加。当在含有10%血清的培养基中培养时，表达E2F1d87的细胞（但不包括表达E2F1的细胞）具有极其圆润的形态。这些圆润的细胞缺乏可检测到的微丝、微管和粘着斑。然而，当将这些细胞在含有低血清（0.5%）的培养基中培养时，它们会呈现出正常NIH3T3细胞的扁平形态和细胞骨架结构。
