Amplification of the Kaposi's sarcoma-associated herpesvirus/human herpesvirus 8 lytic origin of DNA replication is dependent upon a cis-acting AT-rich region and an ORF50 response element and the trans-acting factors ORF50 (K-Rta) and K8 (K-bZIP)
Amplification of the Kaposi's sarcoma-associated herpesvirus/human herpesvirus 8 lytic origin of DNA replication is dependent upon a cis-acting AT-rich region and an ORF50 response element and the trans-acting factors ORF50 (K-Rta) and K8 (K-bZIP)
复制标题
DOI：
10.1016/j.virol.2003.10.016
复制
发表时间：
2004-01-20
期刊：
影响因子：
3.7
通讯作者：
Pari, GS
中科院分区：
文献类型：
--
作者：
AuCoin, DP;Colletti, KS;Pari, GS
卡波西肉瘤相关疱疹病毒（KSHV），也称为人类疱疹病毒8（HHV 8），与EB病毒（EBV）具有显著的序列同源性。在细胞培养中，HHV 8主要是潜伏的，与裂解复制相关的病毒基因不表达。两个裂解的DNA复制起点（oriLyt）存在于HHV 8基因组内，并由富含GC的DNA序列相邻的富含AT的区域组成。我们现在已经确定了oriLy依赖的DNA复制所需的基本顺式和反式作用元件。瞬时复制试验表明，两个AT丰富的元素，三个共识AP 1转录因子结合位点，一个ORF 50响应元件（RE），和共识TATA框基序是必不可少的有效的起源依赖性DNA复制。荧光素酶报告构建体的瞬时转染表明，HHV 8 oriLyt的下游区域响应于ORF 50，并表明oriLyt的一部分可能是增强子/启动子。此外，瞬时共转染复制试验阐明了一组裂解DNA复制所需的反式作用因子。这些因子由核心复制蛋白的同源物组成：ORF 6（ssDNA结合蛋白）、ORF 9（DNA聚合酶）、ORF 40 -41（引发酶相关因子）、ORF 44（解旋酶）、ORF 56（引发酶）和ORF 59（聚合酶持续合成因子），以及ORF 50（K-Rta）和K8（K-bZIP），这些因子在所有疱疹病毒中都很常见。(C)2003年爱思唯尔公司All rights reserved.
Kaposi's sarcoma-associated herpesvirus (KSHV), also known as human herpesvirus 8 (HHV8), has significant sequence homology to Epstein-Barr virus (EBV). In cell culture, HHV8 is primarily latent, and viral genes associated with lytic replication are not expressed. Two lytic origins of DNA replication (oriLyt) are present within the HHV8 genome and are composed of an AT-rich region adjacent to GC-rich DNA sequences. We have now identified essential cis- and trans-acting elements required for oriLyt-dependent DNA replication. The transient replication assay was used to show that two AT-rich elements, three consensus AP1 transcription factor-binding sites, an ORF50 response element (RE), and a consensus TATA box motif are essential for efficient origin-dependent DNA replication. Transient transfection of luciferase reporter constructs indicated that the downstream region of the HHV8 oriLyt responds to ORF50 and suggests that part of the oriLyt may be an enhancer/promoter. In addition, a transient cotransfection-replication assay elucidated the set of trans-acting factors required for lytic DNA replication. These factors consist of homologues to the core replication proteins: ORF6 (ssDNA binding protein), ORF9 (DNA polymerase), ORF40-41 (primase-associated factor), ORF44 (helicase), ORT56 (primase), and ORF59 (polymerase processivity factor) common to all herpesviruses along with ORF50 (K-Rta) and K8 (K-bZIP). (C) 2003 Elsevier Inc. All rights reserved.