DOWN-REGULATION OF THE CYCLIN-A PROMOTER IN DIFFERENTIATING HUMAN EMBRYONAL CARCINOMA-CELLS IS MEDIATED BY DEPLETION OF ATF-1 AND ATF-2 IN THE COMPLEX AT THE ATF/CRE SITE
DOWN-REGULATION OF THE CYCLIN-A PROMOTER IN DIFFERENTIATING HUMAN EMBRYONAL CARCINOMA-CELLS IS MEDIATED BY DEPLETION OF ATF-1 AND ATF-2 IN THE COMPLEX AT THE ATF/CRE SITE
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DOI：
10.1006/excr.1995.1053
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发表时间：
1995-02-01
影响因子：
3.7
通讯作者：
ODA, K
中科院分区：
文献类型：
--
作者：
NAKAMURA, T;OKUYAMA, S;ODA, K
人胚胎癌细胞系NEC 14可通过加入N，N ′-六亚甲基双乙酰胺（HMBA）诱导分化。HMBA处理后，细胞周期蛋白A转录水平急剧下降，48 h时已降至原来水平的1/10以下。通过使用报告基因和分析DNA-蛋白质复合物，研究了与这种下调有关的启动子元件。缺失-608和-259之间包含三个GC盒的序列将启动子活性降低至约一半，并且进一步缺失高达-194，消除ATF/CRE位点，导致未分化的NEC 14细胞中原始水平降低至约十分之一。这些序列参与了分化诱导的NEC 14细胞中启动子活性的下调。DNA-蛋白质复合物形成在ATF/CRE网站与未分化和分化诱导的细胞制备的提取物给出了相同的足迹，但表现出不同的电泳迁移率。用ATF-1和ATF-2的特异性抗体进行的超移试验表明，在诱导NEC 14细胞分化后，这两种因子在复合物中被耗尽。ATF/CRE位点和GC盒似乎也参与了细胞周期蛋白A启动子在生长刺激的人成纤维细胞中G（1）/S边界的上调。(C)出版社：Academic Press
The human embryonal carcinoma cell line NEC14 can be induced to differentiate by the addition of N,N'-hexamethylene-bis-acetamide (HMBA). After treatment with HMBA, the level of cyclin A transcript decreased steeply, reaching less than one-tenth of the original level by 48 h. The promoter elements concerned with this down-regulation were studied by using reporter genes and by analyzing DNA-protein complexes. The deletion of the sequence between -608 and -259 containing three GC boxes decreased the promoter activity to about a half, and further deletion up to -194, eliminating the ATF/CRE site, resulted in a decrease to about a tenth of the original level in undifferentiated NEC14 cells. These sequences were involved in down-regulation of the promoter activity in differentiation-induced NEC14 cells. DNA-protein complexes formed at the ATF/CRE site with extracts prepared from undifferentiated and differentiation-induced cells gave the same footprint, but showed different electrophoretic mobilities. The supershift assay with specific antibodies against ATF-1 and ATF-2 indicated that both factors were depleted in the complex after induction of NEC14 cell differentiation. Both the ATF/CRE site and GC boxes seemed to be also involved in up-regulation of the cyclin A promoter in growth-stimulated human fibroblasts at the G(1)/S boundary. (C) 1995 Academic Press, Inc.