title: A microRNA of infectious laryngotracheitis virus can downregulate and direct cleavage of ICP4 mRNA.
abstract: Viral microRNAs regulate gene expression using either translational repression or mRNA cleavage and decay. Two microRNAs from infectious laryngotracheitis virus (ILTV), iltv-miR-I5 and iltv-miR-I6, map antisense to the ICP4 gene. Post-transcriptional repression by these microRNAs was tested against a portion of the ICP4 coding sequence cloned downstream of firefly luciferase. Luciferase activity was downregulated by approximately 60% with the iltv-miR-I5 mimic. Addition of an iltv-miR-I5 antagomiR or mutagenesis of the target seed sequence alleviated this effect. The iltv-miR-I5 mimic, when co-transfected with a plasmid expressing ICP4, reduced ICP4 transcript levels by approximately 50%, and inhibition was relieved by an iltv-miR-I5 antagomiR. In infected cells, iltv-miR-I5 mediated cleavage at the canonical site, as indicated by modified RACE analysis. Thus, in this system, iltv-miR-I5 decreased ILTV ICP4 mRNA levels via transcript cleavage and degradation. Downregulation of ICP4 could impact the balance between the lytic and latent states of the virus in vivo.
authors.affiliation: Elcriton, Inc. 15 Innovation Way, Suite 288, Newark, DE 19711, USA.
authors.forename: Lisa A
authors.initials: LA
authors.lastname: Waidner
authors.forename: Joan
authors.initials: J
authors.lastname: Burnside
authors.forename: Amy S
authors.initials: AS
authors.lastname: Anderson
authors.forename: Erin L
authors.initials: EL
authors.lastname: Bernberg
authors.forename: Marcelo A
authors.initials: MA
authors.lastname: German
authors.forename: Blake C
authors.initials: BC
authors.lastname: Meyers
authors.forename: Pamela J
authors.initials: PJ
authors.lastname: Green
authors.forename: Robin W
authors.initials: RW
authors.lastname: Morgan
mesh_terms: D000818:Animals; D019677:Artificial Gene Fusion; D019556:COS Cells; D002522:Chlorocebus aethiops; D015536:Down-Regulation; D015967:Gene Expression Regulation, Viral; D017930:Genes, Reporter; D025921:Iltovirus / Q000502:physiology*; D008156:Luciferases / Q000096:biosynthesis / Q000235:genetics; D035683:MicroRNAs / Q000378:metabolism*; D020871:RNA Stability; D012333:RNA, Messenger / Q000096:biosynthesis* / Q000235:genetics; D012367:RNA, Viral / Q000378:metabolism*; D014764:Viral Proteins / Q000096:biosynthesis*; D014779:Virus Replication
chemical_list: C093684:ICP4 protein, infectious laryngotracheitis virus; D035683:MicroRNAs; D012333:RNA, Messenger; D012367:RNA, Viral; D014764:Viral Proteins; D008156:Luciferases