Cytomegalovirus microRNAs facilitate persistent virus infection in salivary glands.

Micro (mi)RNAs are small non-coding RNAs that regulate the expression of their targets' messenger RNAs through both translational inhibition and regulation of target RNA stability. Recently, a number of viruses, particularly of the herpesvirus family, have been shown to express their own miRNAs to control both viral and cellular transcripts. Although some targets of viral miRNAs are known, their function in a physiologically relevant infection remains to be elucidated.

Systematic analysis of viral and cellular microRNA targets in cells latently infected with human gamma-herpesviruses by RISC immunoprecipitation assay.

The mRNA targets of microRNAs (miRNAs) can be identified by immunoprecipitation of Argonaute (Ago) protein-containing RNA-induced silencing complexes (RISCs) followed by microarray analysis (RIP-Chip). Here we used Ago2-based RIP-Chip to identify transcripts targeted by Kaposi's sarcoma-associated herpesvirus (KSHV) miRNAs (n = 114), Epstein-Barr virus (EBV) miRNAs (n = 44), and cellular miRNAs (n = 2337) in six latently infected or stably transduced human B cell lines. Of the six KSHV miRNA targets chosen for validation, four showed regulation via their 3'UTR, while two showed regulation via binding sites within coding sequences.