Introduction: N6 -methyladenosine (m6 A) is the most prevalent modification that occurs in messenger RNA (mRNA), affecting mRNA splicing, translation, and stability. This modification is reversible, and its related biological functions are mediated by "writers," "erasers," and "readers." The field of viral epitranscriptomics and the role of m6 A modification in virus-host interaction have attracted much attention recently. When Epstein-Barr virus (EBV) infects a human B lymphocyte, it goes through three phases: the pre-latent phase, latent phase, and lytic phase. Little is known about the viral and cellular m6 A epitranscriptomes in EBV infection, especially in the pre-latent phase during de novo infection.
Methods: Methylated RNA immunoprecipitation sequencing (MeRIP-seq) and MeRIP-RT-qPCR were used to determine the m6 A-modified transcripts during de novo EBV infection. RIP assay was used to confirm the binding of EBNA2 and m6 A readers. Quantitative reverse-transcription polymerase chain reaction (RT-qPCR) and Western blot analysis were performed to test the effect of m6 A on the host and viral gene expression.
Results: Here, we provided mechanistic insights by examining the viral and cellular m6 A epitranscriptomes during de novo EBV infection, which is in the pre-latent phase. EBV EBNA2 and BHRF1 were highly m6 A-modified upon EBV infection. Knockdown of METTL3 (a "writer") decreased EBNA2 expression levels. The emergent m6 A modifications induced by EBV infection preferentially distributed in 3' untranslated regions of cellular transcripts, while the lost m6 A modifications induced by EBV infection preferentially distributed in coding sequence regions of mRNAs. EBV infection could influence the host cellular m6 A epitranscriptome.
Conclusions: These results reveal the critical role of m6 A modification in the process of de novo EBV infection.
Keywords: BHRF1; EBNA2; Epstein-Barr virus; METTL3; RNA m6A methylation.
© 2021 The Authors. Immunity, Inflammation and Disease published by John Wiley & Sons Ltd.