Splicing Diversity of the Human OCLN Gene and Its Biological Significance for Hepatitis C Virus Entry
Splicing Diversity of the Human OCLN Gene and Its Biological Significance for Hepatitis C Virus Entry
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DOI：
10.1128/jvi.00196-10
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发表时间：
2010-07-01
影响因子：
5.4
通讯作者：
Prokunina-Olsson, Ludmila
中科院分区：
文献类型：
--
作者：
Kohaar, Indu;Ploss, Alexander;Prokunina-Olsson, Ludmila
丙型肝炎病毒持续感染是慢性肝病的主要致病因素，包括肝硬变和癌症。最近的一项研究发现，封闭蛋白(OCLN)是一种完整的紧密连接蛋白，是丙型肝炎病毒进入细胞的关键因素之一。我们研究了OCLN在正常肝脏中的剪接多样性，并观察到不同剪接变体的不同表达，包括两种已知形式(WT-OCLN和OCLN-ex4del)和六种新形式(OCLN-ex7ext、Ocln-ex3pdel、Ocln-ex3del、Ocln-ex3-4del、Ocln-ex3p-9pdel和Ocln-ex3p-7pdel)。重组蛋白WT-OCLN和OCLN-ex7ext保留了与丙型肝炎病毒相互作用的Marvel结构域，表达于细胞膜上，体外感染力测定显示对丙型肝炎病毒的感染是允许的。所有其他形式缺乏Marvel结构域，在细胞质中表达，并且不允许丙型肝炎病毒感染。此外，我们观察到OCLN剪接形式在人类组织和细胞系中的不同表达。我们的研究表明，OCLN显著的自然剪接多样性可能有助于丙型肝炎病毒的组织趋向性，并可能改变人类丙型肝炎病毒感染的结局。对OCLN表达的调控和对丙型肝炎病毒感染易感性至关重要的遗传因素仍有待阐明。
Persistent hepatitis C virus (HCV) infection is a primary etiological factor for the development of chronic liver disease, including cirrhosis and cancer. A recent study identified occludin (OCLN), an integral tight junction protein, as one of the key factors for HCV entry into cells. We explored the splicing diversity of OCLN in normal human liver and observed variable expression of alternative splice variants, including two known forms (WT-OCLN and OCLN-ex4del) and six novel forms (OCLN-ex7ext, OCLN-ex3pdel, OCLN-ex3del, OCLN-ex3-4del, OCLN-ex3p-9pdel, and OCLN-ex3p-7pdel). Recombinant protein isoforms WT-OCLN and OCLN-ex7ext, which retained the HCV-interacting MARVEL domain, were expressed on the cell membrane and were permissive for HCV infection in in vitro infectivity assays. All other forms lacked the MARVEL domain, were expressed in the cytoplasm, and were nonpermissive for HCV infection. Additionally, we observed variable expression of OCLN splicing forms across human tissues and cell lines. Our study suggests that the remarkable natural splicing diversity of OCLN might contribute to HCV tissue tropism and possibly modify the outcome of HCV infection in humans. Genetic factors crucial for regulation of OCLN expression and susceptibility to HCV infection remain to be elucidated.