Serum response factor is required for immediate-early gene activation yet is dispensable for proliferation of embryonic stem cells
Serum response factor is required for immediate-early gene activation yet is dispensable for proliferation of embryonic stem cells
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DOI：
10.1128/mcb.21.8.2933-2943.2001
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发表时间：
2001-04-01
影响因子：
5.3
通讯作者：
Nordheim, A
中科院分区：
文献类型：
--
作者：
Schratt, G;Weinhold, B;Nordheim, A
向促分裂原饥饿的细胞中添加血清激活细胞立即早期基因（IEG）反应。血清反应因子（SRF）有助于在G（0）-G（1）细胞周期转换期间对许多IEG进行这种有丝分裂原刺激的转录诱导。SRF也被认为是细胞周期进程所必需的，因为特异性抗血清或反义RNA对SRF活性的损害先前已显示出阻断哺乳动物细胞增殖。相比之下，Srf（-1-）小鼠胚胎生长发育至E6.0。利用胚胎干（ES）细胞系统，我们在此证明野生型ES细胞在血清撤除后不经历完全的细胞周期停滞，但它们可以产生有效的IEG反应。然而，这种IEG反应在Srf（-1-）ES细胞中严重受损，这提供了IEG激活依赖于SRF的第一个遗传证据。此外，Srf（-1-）ES细胞显示改变的细胞形态，皮质肌动蛋白表达减少，明胶上的平板接种效率受损。然而，尽管存在这些缺陷，Srf（-1-）ES细胞的增殖速率基本上没有改变，表明SRF功能不是ES细胞周期进展所必需的。
Addition of serum to mitogen-starved cells activates the cellular immediate-early gene (IEG) response. Serum response factor (SRF) contributes to such mitogen-stimulated transcriptional induction of many IEGs during the G(0)-G(1) cell cycle transition. SRF is also believed to be essential for cell cycle progression, as impairment of SRF activity by specific antisera or antisense RNA has previously been shown to block mammalian cell proliferation. In contrast, Srf(-1-) mouse embryos grow and develop up to E6.0. Using the embryonic stem (ES) cell system, we demonstrate here that wild-type ES cells do not undergo complete cell cycle arrest upon serum withdrawal but that they can mount an efficient IEG response, This IEG response, however, is severely impaired in Srf(-1-) ES cells, providing the first genetic proof that IEG activation is dependent upon SRF, Also, Srf(-1-) ES cells display altered cellular morphology, reduced cortical actin expression, and an impaired plating efficiency on gelatin. Yet, despite these defects, the proliferation rates of Srf(-1-) ES cells are not substantially altered, demonstrating that SRF function is not required for ES cell cycle progression.