Sterol-dependent transcriptional regulation of sterol regulatory element-binding protein-2
Sterol-dependent transcriptional regulation of sterol regulatory element-binding protein-2
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DOI：
10.1074/jbc.271.43.26461
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发表时间：
1996-10-25
影响因子：
4.8
通讯作者：
Maeda, M
中科院分区：
文献类型：
--
作者：
Sato, R;Inoue, J;Maeda, M
我们在这篇手稿中表明，在培养的HeLa细胞的细胞固醇水平调节的固醇调节元件结合蛋白-a（SREBP-2）的mRNA的表达。我们已经克隆了编码人SREBP-2的基因的5 '侧翼区。该区域的表征显示最小50个碱基对片段，其含有与人LDL受体启动子中的一个相同的10个碱基对固醇调节元件1（SRE-1），当与荧光素酶报告基因融合时赋予固醇响应性。截短的SREBP-2蛋白（氨基酸残基1-481）的强制表达也表明，该上游片段含有转录激活所需的信息。使用报告基因的突变体形式的荧光素酶测定揭示，固醇依赖性转录调节由两个邻近的基序SRE-1和NF-γ结合位点（反向CCAAT盒，ATTGGC）介导;据报道，后者在3-羟基-3-甲基戊二酰辅酶A合酶和法呢基二磷酸合酶基因的固醇依赖性调节中起关键作用（杰克逊，S. M.，Ericsson，J.，Osborne，T. F.、和Edwards，P. A.（1995）J.Biol.Chem.270，21445-21448），凝胶迁移率变动分析证明转录因子NF-Y确实与ATTGGC序列结合。这些发现表明，SREBP-2的活性不仅在转录后通过前体蛋白的蛋白水解活化来控制，而且在转录时通过其自身与NF-Y一起来控制。
We show in this manuscript that expression of the mRNA for sterol regulatory element-binding protein-a (SREBP-2) is regulated by the cellular sterol level in cultured HeLa cells. We have cloned the 5'-flanking region of the gene encoding human SREBP-2. Characterization of this region shows the minimum 50-base pair segment, which contains a 10-base pair sterol regulatory element 1 (SRE-1) identical to the one in the human LDL receptor promoter, confers sterol responsiveness when fused to the luciferase reporter gene. Enforced expression of the truncated SREBP-2 protein (amino acid residues 1-481) also shows that this upstream segment contains the information required for transcriptional activation. The luciferase assays using mutant versions of the reporter genes reveal that the sterol dependent transcriptional regulation is mediated by two nearby motifs, the SRE-1 and the NF-Y binding site (the inverted CCAAT box, ATTGGC); the latter is reported to play a critical role in sterol dependent regulation of 3-hydroxy-3-methylglutaryl-coenzyme A synthase and farnesyl diphosphate synthase genes (Jackson, S. M., Ericsson, J., Osborne, T. F., and Edwards, P. A. (1995) J. Biol. Chem. 270, 21445-21448), Gel mobility shift assays demonstrate that the transcription factor NF-Y truly binds to the ATTGGC sequence, These findings suggest that the activity of SREBP-2 is controlled not only post-translationally by proteolytic activation of the precursor protein but also transcriptionally by itself together with NF-Y.