Human butyrate-induced transcript 1 interacts with hepatitis C virus NS5A and regulates viral replication
Human butyrate-induced transcript 1 interacts with hepatitis C virus NS5A and regulates viral replication
复制标题
DOI：
10.1128/jvi.02153-07
复制
发表时间：
2008-03-01
影响因子：
5.4
通讯作者：
Matsuura, Yoshiharu
中科院分区：
文献类型：
--
作者：
Taguwa, Shuhei;Okamoto, Toru;Matsuura, Yoshiharu
丙型肝炎病毒（HCV）非结构蛋白5A（NS 5A）是病毒基因组复制所需的，并参与多种宿主信号传导途径。为了进一步了解NS 5A在HCV复制中的功能作用，我们使用NS 5A作为诱饵，通过酵母双杂交系统筛选人cDNA文库，并确定人丁酸诱导转录本1（hB-ind 1）作为一种新的NS 5A结合蛋白。内源性和外源性表达的hB-ind 1通过hB-ind 1的卷曲螺旋结构域与不同基因型的NS 5A共免疫沉淀。小干扰RNA（siRNA）介导的hB-ind 1在人肝癌细胞系中的敲低抑制HCV RNA复制子的复制和HCV基因型2a株JFH 1的感染性颗粒的产生。此外，这些减少被siRNA抗性hB-ind 1突变体的表达所抵消。在参与HCV复制的NS 5A结合宿主蛋白中，hB-ind 1表现出与FKBP 8的结合，并且hB-ind 1通过其N-末端p23同源结构域中的FxxW基序与Hsp 90相互作用。在hB-ind 1敲低细胞系中，HCV RNA复制子的复制和JFH 1病毒感染性颗粒的产生的损害不能通过表达siRNA抗性hB-ind 1突变体（其中FxxW基序被AxxA取代）来逆转。这些结果表明hB-ind 1通过与病毒和宿主蛋白相互作用在HCV RNA复制和JFH 1病毒的繁殖中起着至关重要的作用。
Hepatitis C virus (HCV) nonstructural protein 5A (NS5A) is required for the replication of the viral genome and is involved in several host signaling pathways. To gain further insight into the functional role of NS5A in HCV replication, we screened human cDNA libraries by a yeast two-hybrid system using NS5A as the bait and identified human butyrate-induced transcript 1 (hB-ind1) as a novel NS5A-binding protein. Endogenously and exogenously expressed hB-ind1 was coimmunoprecipitated with NS5A of various genotypes through the coiled-coil domain of hB-ind1. The small interfering RNA (siRNA)-mediated knockdown of hB-ind1 in human hepatoma cell lines suppressed the replication of HCV RNA replicons and the production of infectious particles of HCV genotype 2a strain JFH1. Furthermore, these reductions were canceled by the expression of an siRNA-resistant hB-ind1 mutant. Among the NS5A-binding host proteins involved in HCV replication, hB-ind1 exhibited binding with FKBP8, and hB-ind1 interacted with Hsp90 through the FxxW motif in its N-terminal p23 homology domain. The impairment of the replication of HCV RNA replicons and of the production of infectious particles of JFH1 virus in the hB-ind1 knockdown cell lines was not reversed by the expression of an siRNA-resistant hB-ind1 mutant in which the FxxW motif was replaced by AxxA. These results suggest that hB-ind1 plays a crucial role in HCV RNA replication and the propagation of JFH1 virus through interaction with viral and host proteins.