Host Factors in the Replication of Positive-Strand RNA Viruses

Viruses are obligate, intracellular parasitesthat depend on host cells for successful propagation. Upon infection of host cells, positivestrand RNA viruses exploit and hijack cellularmachinery and reprogram these cells into viral“factories” through various protein-protein, protein-RNA, and protein-lipid interactions. Themolecular interplay between host factors andi n v a d i n g v i r u s e s i s a c o n t i n u o u s p r o c e s sthroughout the entire viral life cycle and determines virus host range and viral pathogenesis,as well as driving viral evolution. Studies ofhost factors have contributed insights into their normal cellular functions and helped identifyattractive targets for antiviral drug development. With the development of high throughputscreening, functional genomics, and proteomics technologies, host factors participating inviral life cycles have been identified rapidly in recent years. In this review, we summarizethe recent advances in virus-host cell interactions in positive-strand RNA virus infectionsand focus on host factors that facilitate viral replication.