C-FOS SEQUENCES NECESSARY FOR BASAL EXPRESSION AND INDUCTION BY EPIDERMAL GROWTH-FACTOR, 12-O-TETRADECANOYL PHORBOL-13-ACETATE, AND THE CALCIUM IONOPHORE
C-FOS SEQUENCES NECESSARY FOR BASAL EXPRESSION AND INDUCTION BY EPIDERMAL GROWTH-FACTOR, 12-O-TETRADECANOYL PHORBOL-13-ACETATE, AND THE CALCIUM IONOPHORE
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DOI：
10.1128/mcb.7.10.3490
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发表时间：
1987-10-01
影响因子：
5.3
通讯作者：
ROEDER, RG
中科院分区：
文献类型：
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作者：
FISCH, TM;PRYWES, R;ROEDER, RG
我们通过将 c-fos 启动子突变体转染 HeLa 和 A431 细胞，研究了表皮生长因子 (EGF)、12-O-十四烷酰佛波醇-13-乙酸酯 (TPA) 和钙离子载体 A23187 诱导人 c-fos 基因的序列要求。 HeLa 细胞中 EGF 和 TPA 的诱导需要存在位于相对于 mRNA 帽位点 -317 至 -298 的 c-fos 增强子。然而，A23187 并不诱导转染基因的表达，尽管它强烈诱导内源基因的表达，这表明它与 EGF 和 TPA 相比具有不同的诱导要求。我们还研究了增强子下游的启动子序列在 c-fos 的一般表达和诱导中的作用。 -97 和 -76 之间的序列（包括 8 个碱基对的完美同向重复序列）对于有效的通用表达是必需的，但对于基因的诱导不需要。通过凝胶迁移率变动分析检测到核提取物中与该序列特异性结合的因子。相对于 mRNA 帽位点位于 -63 和 -57 之间的 7 碱基对序列先前显示对于小鼠 c-fos 的一般表达很重要，对于人类基因的一般表达也很重要。此外，该元件对于 EGF 和 TPA 的诱导能力很重要，因为当在转染测定中分析保留增强子但缺乏 -63 至 -57 序列元件的内部缺失突变体时，诱导显着降低。
We have investigated the sequence requirements for induction of the human c-fos gene by epidermal growth factor (EGF), 12-O-tetradecanoyl phorbol-13-acetate (TPA), and the calcium ionophore A23187 by transfecting c-fos promoter mutants into HeLa and A431 cells. Induction by both EGF and TPA in HeLa cells required the presence of the c-fos enhancer located at -317 to -298 relative to the mRNA cap site. A23187, however, did not induce expression of the transfected gene, even though it strongly induced expression of the endogenous gene, suggesting that it has different requirements for induction than do EGF and TPA. We have also investigated the role of promoter sequences downstream of the enhancer in general expression and induction of c-fos. A sequence between -97 and -76, which includes an 8-base-pair perfect direct repeat, was needed for efficient general expression but not for induction of the gene. A factor in nuclear extracts that bound specifically to this sequence was detected by a gel mobility shift assay. A 7-base-pair sequence, located between -63 and -57 relative to the mRNA cap site and previously shown to be important for general expression of mouse c-fos, was also important for general expression of the human gene. In addition, this element was important for inducibility by EGF and TPA, since induction was significantly reduced when internal deletion mutants that retained the enhancer but lacked the -63 to -57 sequence element were analyzed in transfection assays.