OVERLAPPING INITIATOR AND TATA BOX FUNCTIONS IN THE BASAL CORE PROMOTER OF HEPATITIS-B VIRUS
OVERLAPPING INITIATOR AND TATA BOX FUNCTIONS IN THE BASAL CORE PROMOTER OF HEPATITIS-B VIRUS
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DOI：
10.1128/jvi.69.6.3647-3657.1995
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发表时间：
1995-06-01
影响因子：
5.4
通讯作者：
TING, LP
中科院分区：
文献类型：
--
作者：
CHEN, IH;HUANG, CJ;TING, LP
B型肝炎病毒核心启动子的转录调控是病毒生命周期中的重要事件。两种信息，前核心和前基因组RNA，起始间隔30个核苷酸，由核心启动子产生。前核心RNA编码核衣壳蛋白和前基因组RNA核心和聚合酶。后一种转录物还充当通过逆转录进行病毒基因组复制的模板。我们以前已经定义了一个基本的核心启动子，它包含四个TA丰富的序列（TA1至TA4），但没有典型的TATA元件，可以指导转录的两个消息。在这项研究中，我们证明了一段含有TA4的15个核苷酸足以指导前核心和前基因组转录物的精确起始。该序列可以作为起始子和TATA元件。突变分析进一步揭示了两种功能所必需的序列是共定位的。这一发现的基础转录机制和病毒基因表达调控的意义进行了讨论。
The regulation of transcription of the hepatitis B virus core promoter is an important event in the viral life cycle. Two messages, precore and pregenomic RNAs, that are initiated 30 nucleotides apart are produced by the core promoter. Precore RNA encodes nucleocapsid protein and pregenomic RNA core and polymerase. The latter transcript also serves as a-template for viral genome replication via reverse transcription. We have previously defined a basal core promoter, which contains four TA-rich sequences (TA1 through TA4) but no canonical TATA element, that can direct transcription of both messages. In this study, we demonstrated that a stretch of 15 nucleotides containing TA4 is sufficient to direct precise initiation of both precore and pregenomic transcripts. This sequence can function as both an initiator and a TATA element. Mutational analysis further revealed that sequences essential for either function are colocalized. The significance of this finding with respect to the basal transcription mechanism and regulation of viral gene expression is discussed.