Mitogen-Activated Protein Kinase Kinase 2, a Novel E2-Interacting Protein, Promotes the Growth of Classical Swine Fever Virus via Attenuation of the JAK-STAT Signaling Pathway.
Mitogen-Activated Protein Kinase Kinase 2, a Novel E2-Interacting Protein, Promotes the Growth of Classical Swine Fever Virus via Attenuation of the JAK-STAT Signaling Pathway.
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丝裂原激活蛋白激酶激酶 2 是一种新型 E2 相互作用蛋白，通过减弱 JAK-STAT 信号通路促进猪瘟病毒的生长
DOI：
10.1128/jvi.01407-16
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发表时间：
2016-11-15
影响因子：
5.4
通讯作者：
Qiu HJ
中科院分区：
文献类型：
--
作者：
Wang J;Chen S;Liao Y;Zhang E;Feng S;Yu S;Li LF;He WR;Li Y;Luo Y;Sun Y;Zhou M;Wang X;Munir M;Li S;Qiu HJ
丝裂原活化蛋白激酶激酶/细胞外调节激酶（MEK 1/2/ERK 1/2）级联反应参与了包括丙型肝炎病毒和登革病毒在内的黄病毒科病毒的复制。该级联反应对猪瘟病毒（CSFV）复制的影响尚不清楚。本研究利用酵母双杂交技术筛选了MEK 2作为CSFV E2蛋白的一种新的结合伴侣。谷胱甘肽S-转移酶下拉，免疫共沉淀和激光共聚焦显微镜测定证实了E2-MEK 2相互作用。E2（氨基酸[aa] 890至1053）和MEK 2（氨基酸266至400）的C末端被定位为对于相互作用至关重要。MEK 2的过表达显著促进CSFV的复制，而慢病毒介导的小发夹RNA敲低MEK 2则显著抑制CSFV的复制。此外，CSFV感染诱导MEK 2的下游信号分子ERK 1/2的双相激活。此外，在PK-15细胞中，用MEK 1/2/ERK 1/2的特异性抑制剂U 0126显著抑制CSFV的复制，而用JAK-STAT特异性抑制剂ruxolitinib阻断干扰素诱导的Janus激酶-信号转导子和转录激活子（JAK-STAT）信号通路后，MEK 2不影响CSFV的复制。综上所述，我们的研究结果表明，MEK 2通过抑制JAK-STAT信号通路正向调节CSFV的复制。丝裂原活化蛋白激酶激酶2（MEK 2）是一种直接在细胞外调节激酶1/2（ERK 1/2）上游起作用的激酶，通过磷酸化作用与Raf和ERK连接。目前，对MEK 2在猪瘟病毒（CSFV）复制中的作用知之甚少，CSFV是一种毁灭性的猪瘟病毒。本文首次研究了MEK 2及其/ERK 1/2级联反应在猪瘟病毒生长中的作用。我们表明，MEK 2正调控猪瘟病毒复制。值得注意的是，我们证明了MEK 2通过抑制干扰素诱导的JAK-STAT信号通路促进CSFV复制，JAK-STAT信号通路是参与先天免疫的关键抗病毒通路。我们的工作揭示了MEK 2在CSFV感染中的新作用，并揭示了瘟病毒与宿主细胞相互作用的分子基础。
ABSTRACT The mitogen-activated protein kinase kinase/extracellular regulated kinase (MEK1/2/ERK1/2) cascade is involved in the replication of several members of the Flaviviridae family, including hepatitis C virus and dengue virus. The effects of the cascade on the replication of classical swine fever virus (CSFV), a fatal pestivirus of pigs, remain unknown. In this study, MEK2 was identified as a novel binding partner of the E2 protein of CSFV using yeast two-hybrid screening. The E2-MEK2 interaction was confirmed by glutathione S-transferase pulldown, coimmunoprecipitation, and laser confocal microscopy assays. The C termini of E2 (amino acids [aa] 890 to 1053) and MEK2 (aa 266 to 400) were mapped to be crucial for the interaction. Overexpression of MEK2 significantly promoted the replication of CSFV, whereas knockdown of MEK2 by lentivirus-mediated small hairpin RNAs dramatically inhibited CSFV replication. In addition, CSFV infection induced a biphasic activation of ERK1/2, the downstream signaling molecules of MEK2. Furthermore, the replication of CSFV was markedly inhibited in PK-15 cells treated with U0126, a specific inhibitor for MEK1/2/ERK1/2, whereas MEK2 did not affect CSFV replication after blocking the interferon-induced Janus kinase-signal transducer and activator of transcription (JAK-STAT) signaling pathway by ruxolitinib, a JAK-STAT-specific inhibitor. Taken together, our results indicate that MEK2 positively regulates the replication of CSFV through inhibiting the JAK-STAT signaling pathway. IMPORTANCE Mitogen-activated protein kinase kinase 2 (MEK2) is a kinase that operates immediately upstream of extracellular regulated kinase 1/2 (ERK1/2) and links to Raf and ERK via phosphorylation. Currently, little is known about the role of MEK2 in the replication of classical swine fever virus (CSFV), a devastating porcine pestivirus. Here, we investigated the roles of MEK2 and the MEK2/ERK1/2 cascade in the growth of CSFV for the first time. We show that MEK2 positively regulates CSFV replication. Notably, we demonstrate that MEK2 promotes CSFV replication through inhibiting the interferon-induced JAK-STAT signaling pathway, a key antiviral pathway involved in innate immunity. Our work reveals a novel role of MEK2 in CSFV infection and sheds light on the molecular basis by which pestiviruses interact with the host cell.