A mammalian herpesvirus uses noncanonical expression and processing mechanisms to generate viral MicroRNAs.

Journal Article (Journal Article)

Canonical primary microRNA (pri-miRNA) precursors are transcribed by RNA polymerase II and then processed by the Drosha endonuclease to generate approximately 60 nt pre-miRNA hairpins. Pre-miRNAs in turn are cleaved by Dicer to generate mature miRNAs. Previously, some short introns, called miRtrons, were reported to fold into pre-miRNA hairpins after splicing and debranching, and miRNAs can also be excised by Dicer cleavage of rare endogenous short hairpin RNAs. Here we report that the miRNAs encoded by murine gamma-herpesvirus 68 (MHV68) are also generated via atypical mechanisms. Specifically, MHV68 miRNAs are transcribed from RNA polymerase III promoters located within adjacent viral tRNA-like sequences. The resultant pri-miRNAs, which bear a 5' tRNA moiety, are not processed by Drosha but instead by cellular tRNase Z, which cleaves 3' to the tRNA to liberate pre-miRNA hairpins that are then processed by Dicer to yield the mature viral miRNAs.

Full Text

Duke Authors

Cited Authors

  • Bogerd, HP; Karnowski, HW; Cai, X; Shin, J; Pohlers, M; Cullen, BR

Published Date

  • January 15, 2010

Published In

Volume / Issue

  • 37 / 1

Start / End Page

  • 135 - 142

PubMed ID

  • 20129062

Pubmed Central ID

  • PMC2818755

Electronic International Standard Serial Number (EISSN)

  • 1097-4164

Digital Object Identifier (DOI)

  • 10.1016/j.molcel.2009.12.016


  • eng

Conference Location

  • United States