本文旨在探讨α-actinin参与丙型肝炎病毒(HCV)复制的机制。将α-actinin转染Huh7.5细胞,用JFH1感染,发现过表达α-actinin可显著增加HCVRNA水平及非结构蛋白表达,感染性HCV颗粒也同时增多。膜漂浮实验显示,α-actinin可与HCV非结构蛋白NS5A共定位于脂筏。抑制内源性α-actinin表达,可使复制子细胞内NS5A表达减少,且对非离子去污剂敏感而从脂筏脱落。免疫荧光实验显示,NS5A与内质网标志分子calnexin核周共定位消失。以上结果提示,α-actinin可通过影响非结构蛋白与脂筏的关联而参与HCV RNA的合成,为临床治疗及研制新型抗HCV药物提供理论依据和实验基础。
Cellular protein α-actinin has been shown to involve in HCV replication in Huh7 HCV replicon cells. However,it is still elusive how α-actinin regulates HCV RNA synthesis. In this study,we attempted to study the mechanism how α-actinin facilitates HCV replication. α-Actinin was transfected into JFH1-infected Huh7.5 cells. The results showed that overexpression of α-actinin significantly increased HCV nonstructural protein expression as well as intracellular and supernatant HCV RNA levels. More infective virus particles were also secreted into media. Membrane flotation analysis indicated that the vast majority of both full-length actinin and NS5A were colocalized in the detergent-resistant membrane (DRM) fractions. Knockdown of α-actinin altered the membrane association pattern of NS5A. Immunofluorescence microscopy analysis showed that NS5A was unable to display a typical pattern of cytoplasmic distribution and colocalize with calnexin on endoplasmic reticulum. Taken together,these results indicate that α-actinin regulates HCV replication through facilitation of NS5A's association with endoplasmic reticulum membrane,and may provide new insights into fundamental cellular processes and identify novel targets for antiviral intervention.