Enterovirus 71 3D Polymerase Interacts with Cellular Protein Nuclear Factor of Activated T Cells, 90-KD to Modulate AU-rich Target mRNA Expression and Viral Translation

• Main Authors: Chieh Hsun Lee, 李杰勳
• Other Authors: S. R. Shih
• Format: Others
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/26057389637638210256

碩士 === 長庚大學 === 醫學生物技術暨檢驗學系 === 101 === Human enterovirus 71 (EV71) genome replication is catalyzed by viral 3D RNA dependent RNA polymerase (RdRP). We identified that 3D polymerase associated with nuclear factor of activated T cell,90-KD (NF90) in EV71 infected cell by matrix-associated laser desorption/ ionization-time of flight (MALDI-TOF) analysis. RNA-binding protein NF90 is an indispensable factor for post-transcriptional regulation and has been implicated in the translational control of target mRNAs which bearing AU-rich signature motif in the 3’UTR. The aim of this study is to elucidate viral 3D polymerase-NF90 interaction that interfere host mRNAs expression and EV71 viral replication. First, we performed confocal microscopy and co-immunoprecipitation to prove that NF90 colocalized with 3D polymerase in cytosol upon EV71 infection and the association between NF90 and 3D polymerase required RNA as a intermediate. Furthermore, We utilized biotinylated RNA-protein pull-down assay to discover that 3D polymerase recombinant protein disrupts the association of NF90 and target mRNAs. On the other hand, we observed NF90 suppress viral replication at early time post infection both in EV71-FLuc replicon transfected and virus infected cells. Taken together, the study demonstrates that EV71 3D polymerase impairs NF90-target mRNAs interaction. Moreover, we also obtained evidence that NF90 suppresses EV71 IRES-driven translation at early time post infection.