The mammalian transcription factor LSF (CP2/LBP-1c) binds cellular promoters modulated by cell growth signals. We demonstrate here that LSF-DNA-binding activity is strikingly regulated by induction of cell growth in human peripheral T lymphocytes. Within 15 min of mitogenic stimulation of these cells, the level of LSF-DNA-binding activity increased by a factor of five. The level of LSF protein in the nucleus remained constant throughout this interval. However, a rapid decrease in the electrophoretic mobility of LSF, attributable to phosphorylation, correlated with the increase in DNA-binding activity. pp44 (ERK1) phosphorylated LSF in vitro on the same residue that was phosphorylated in vivo, specifically at amino acid position 291, as indicated by mutant analysis. As direct verification of the causal relationship between phosphorylation and DNA-binding activity, treatment in vitro of LSF with phosphatase both increased the electrophoretic mobility of the protein and decreased LSF-DNA-binding activity. This modulation of LSF-DNA-binding activity as T cells progress from a resting to a replicating state reveals that LSF activity is regulated during cell growth and suggests that LSF regulates growth-responsive promoters.

译文

哺乳动物转录因子LSF(CP2 / LBP-1c)结合受细胞生长信号调节的细胞启动子。我们在这里证明,LSF-DNA结合活性是由人类外周血T淋巴细胞的细胞生长诱导来显着调节的。在这些细胞的促有丝分裂刺激的15分钟内,LSF-DNA结合活性的水平提高了五倍。在整个间隔期间,核中LSF蛋白的水平保持恒定。但是,可归因于磷酸化的LSF电泳迁移率的快速下降与DNA结合活性的增加有关。突变分析表明,pp44(ERK1)在体外磷酸化的同一残基上,特别是在氨基酸位置291处磷酸化LSF。作为磷酸化与DNA结合活性之间因果关系的直接验证,体外用磷酸酶处理LSF既增加了蛋白质的电泳迁移率,又降低了LSF-DNA结合活性。当T细胞从静止状态发展到复制状态时,对LSF-DNA结合活性的这种调节揭示了LSF活性在细胞生长过程中受到调节,并暗示LSF调节生长响应性启动子。

+1
+2
100研值 100研值 ¥99课程
检索文献一次
下载文献一次

去下载>

成功解锁2个技能,为你点赞

《SCI写作十大必备语法》
解决你的SCI语法难题!

技能熟练度+1

视频课《玩转文献检索》
让你成为检索达人!

恭喜完成新手挑战

手机微信扫一扫,添加好友领取

免费领《Endnote文献管理工具+教程》

微信扫码, 免费领取

手机登录

获取验证码
登录