Kaposi's sarcoma-associated herpesvirus latent protein LANA interacts with HIF-1α to upregulate RTA expression during hypoxia:: Latency control under low oxygen conditions
Kaposi's sarcoma-associated herpesvirus latent protein LANA interacts with HIF-1α to upregulate RTA expression during hypoxia:: Latency control under low oxygen conditions
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DOI：
10.1128/jvi.00689-06
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发表时间：
2006-08-01
影响因子：
5.4
通讯作者：
Robertson, Erle S.
中科院分区：
文献类型：
--
作者：
Cai, Qiliang;Lan, Ke;Robertson, Erle S.
低氧可诱导原发性渗出性淋巴瘤（PEL）细胞中卡波西肉瘤相关疱疹病毒（KSHV）的裂解性复制。然而，KSHV溶解性再激活的分子机制尚不清楚。在这里，我们表明，潜伏相关核抗原（拉娜），它在调节病毒和细胞基因表达中起着至关重要的作用，直接与低氧反应，缺氧诱导因子-1 α（HIF-1 α）。拉娜不仅能增强HIF-1 α的转录活性，还能提高其mRNA水平。免疫共沉淀和免疫荧光研究证明了在缺氧期间，在瞬时转染的293 T细胞以及PEL细胞系中拉娜和HIF-1 α之间的物理相互作用。通过序列分析，在必需裂解基因Rta启动子中鉴定了几个推定的缺氧反应元件（HRE-1至-6）。报告基因分析显示HRE-2（-1130至-1123）和HRE-5和HRE-6（内含子序列内分别为+234至+241和+812至+820）对于LANA介导的HIF-1 α应答是必要的和足够的。电泳迁移率变动分析表明，HIF-1 α依赖性结合的拉娜蛋白复合物特异性的HRE-2，-5，和-6基序内的启动子调控序列。这项研究表明，低氧诱导的KSHV裂解性复制至少部分是通过HIF-1 α与结合到Rta启动子的HRE基序的拉娜的合作介导的。
Hypoxia can induce lytic replication of Kaposi's sarcoma-associated herpesvirus (KSHV) in primary effusion lymphoma (PEL) cells. However, the molecular mechanism of lytic reactivation of KSHV by hypoxia remains unclear. Here we show that the latency-associated nuclear antigen (LANA), which plays a crucial role in modulating viral and cellular gene expression, directly associated with a low oxygen responder, hypoxia-inducible factor-1 alpha (HIF-1 alpha). LANA enhanced not only the transcriptional activities of HIF-1 alpha but also its mRNA level. Coimmunoprecipitation and immunotluorescence studies documented a physical interaction between LANA and HIF-1 alpha in transiently transfected 293T cells as well as in PEL cell lines during hypoxia. Through sequence analysis, several putative hypoxia response elements (HRE-1 to -6) were identified in the essential lytic gene Rta promoter. Reporter assays showed that HRE-2 (-1130 to -1123) and HRE-5 and HRE-6 (+234 to +241 and +812 to +820, respectively, within the intron sequence) were necessary and sufficient for the LANA-mediated HIF-1 alpha response. Electrophoretic mobility shift assays showed HIF-1 alpha dependent binding of a LANA protein complex specifically to the HRE-2, -5, and -6 motifs within the promoter regulatory sequences. This study demonstrates that hypoxia-induced KSHV lytic replication is mediated at least in part through cooperation of HIF-1 alpha with LANA bound to the HRE motifs of the Rta promoter.