Sive H L, Heintz N, Roeder R G
Mol Cell Biol. 1986 Oct;6(10):3329-40. doi: 10.1128/mcb.6.10.3329-3340.1986.
As part of our studies on the cell cycle regulation of human histone gene expression, we examined the elements governing transcription of a human histone H2B gene in nuclear extracts derived from human HeLa cells. Circular templates were transcribed at 5- to 10-fold higher levels than were linear templates. A series of deletion, linker-substitution, and point mutants defined cis-acting promoter sequences that were recognized in nuclear extracts. These sequences extended from 118 to 21 base pairs 5' to the transcription initiation site. Elements recognized included (from 5' to 3') a series of direct repeats, a CCAAT homology, a human histone-specific hexamer, an H2B consensus element, and a TATA box. Sequence elements 5' to the hexamer were required for its function. In contrast, the H2B consensus element could function independently of more-5' promoter elements and in turn was essential for the function of upstream elements. An interesting feature of this consensus is that its core octanucleotide (ATTTGCAT) is found in several nonhistone genes. By comparison with functional elements in an H4 promoter, we infer that a combinatorial interaction of general and gene-specific factors may contribute to the S-phase elevation of H2B transcription.
作为我们对人类组蛋白基因表达的细胞周期调控研究的一部分，我们检测了源自人类HeLa细胞的核提取物中调控人类组蛋白H2B基因转录的元件。环状模板的转录水平比线性模板高5至10倍。一系列缺失、接头替换和点突变确定了在核提取物中被识别的顺式作用启动子序列。这些序列从转录起始位点上游118个碱基对延伸至21个碱基对。所识别的元件包括（从5'到3'）一系列直接重复序列、一个CCAAT同源序列、一个人类组蛋白特异性六聚体、一个H2B共有元件和一个TATA盒。六聚体上游的序列元件是其功能所必需的。相反，H2B共有元件可以独立于更上游的启动子元件发挥作用，反过来，它对于上游元件的功能也是必不可少的。这个共有元件的一个有趣特征是其核心八聚体（ATTTGCAT）存在于几个非组蛋白基因中。通过与H4启动子中的功能元件进行比较，我们推断一般因子和基因特异性因子的组合相互作用可能有助于H2B转录在S期的升高。
