Dynamics of Human and Viral RNA Methylation during Zika Virus Infection.

Infection with the flavivirus Zika (ZIKV) causes neurological, immunological, and developmental defects through incompletely understood mechanisms. We report that ZIKV infection affects viral and human RNAs by altering the topology and function of N-adenosine methylation (mA), a modification affecting RNA structure and function. mA nucleosides are abundant in ZIKV RNA, with twelve mA peaks identified across full-length ZIKV RNA. mA in ZIKV RNA is controlled by host methyltransferases METTL3 and METTL14 and demethylases ALKBH5 and FTO, and knockdown of methyltransferases increases, while silencing demethylases decreases, ZIKV production. YTHDF family proteins, which regulate the stability of mA-modified RNA, bind to ZIKV RNA, and their silencing increases ZIKV replication. Profiling of the mA methylome of host mRNAs reveals that ZIKV infection alters mA location in mRNAs, methylation motifs, and target genes modified by methyltransferases. Our results identify a mechanism by which ZIKV interacts with and alters host cell functions.