CDF-1, a novel E2F-unrelated factor, interacts with cell cycle-regulated repressor elements in multiple promoters
CDF-1, a novel E2F-unrelated factor, interacts with cell cycle-regulated repressor elements in multiple promoters
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DOI：
10.1093/nar/25.24.4915
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发表时间：
1997-12-15
影响因子：
14.9
通讯作者：
Müller, R
中科院分区：
文献类型：
--
作者：
Liu, NS;Lucibello, FC;Müller, R
cdc 25 C、cdc 2和cyclin A启动子通过两个相邻的蛋白结合位点CDE和CD 4受转录抑制的控制。在本研究中，我们鉴定了一个与cdc 25 C CDE-CD 4模块相互作用的因子CDF-1，CDF-1在体外以协同的方式与大沟中的CDE和小格罗夫中的CD 4结合，与体内结合数据及其作为周期性阻遏物的推定功能一致，在细胞周期进程中，细胞核提取物中CDF-1与DNA的结合被下调。CDF-1也与cdc 2和细胞周期蛋白A启动子的CDE-β模块结合，但不与B-myb启动子中的E2 F位点结合。相反，E2 F复合物不识别cdc 25 C CDE-β，并且CDF-1与所有已知的E2 F和DP家族成员在免疫学上无关。这表明E2 F和CDF介导的阻遏作用受细胞周期不同阶段不同因素的控制，而E2 F介导的阻遏作用似乎与早期上调的基因有关。（在中间G（1）附近），如B-myb，CDE-β控制的基因，如cdc 25 C，cdc 2和细胞周期蛋白A，后来变得去抑制，最后，天然核提取物在甘油梯度上的分级分离导致CDF-1与E2 F复合物和pRb家族的口袋蛋白分离。这强调了CDF-1不是E2 F家族成员的结论，并指出CDF-1和E2 F在细胞周期调控方面的深刻差异。
The cdc25C, cdc2 and cyclin A promoters are controlled by transcriptional repression through two contiguous protein binding sites, termed the CDE and CHR, In the present study we have identified a factor, CDF-1, which interacts with the cdc25C CDE-CHR module, CDF-1 binds to the CDE in the major groove and to the CHR in the minor grove in a cooperative fashion in vitro, in a manner similar to that seen by genomic footprinting, In agreement with in vivo binding data and its putative function as a periodic repressor, DNA binding by CDF-1 in nuclear extracts is down-regulated during cell cycle progression. CDF-1 also binds avidly to the CDE-CHR modules of the cdc2 and cyclin A promoters, but not to the E2F site in the B-myb promoter, Conversely, E2F complexes do not recognize the cdc25C CDE-CHR and CDF-I is immunologically unrelated to all known E2F and DP family members. This indicates that E2F- and CDF-mediated repression is controlled by different factors acting at different stages during the cell cycle, While E2F-mediated repression seems to be associated with genes that are up-regulated early (around mid G(1)), such as B-myb, CDE-CHR-controlled genes, such as cdc25C, cdc2 and cyclin A, become derepressed later, Finally, the fractionation of native nuclear extracts on glycerol gradients leads to separation of CDF-1 from both E2F complexes and pocket proteins of the pRb family. This emphasizes the conclusion that CDF-1 is not an E2F family member and points to profound differences in the cell cycle regulation of CDF-1 and E2F.