A Kaposi's sarcoma virus RNA element that increases the nuclear abundance of intronless transcripts

Nicholas K. Conrad, Joan A. Steitz

Research output: Contribution to journalArticlepeer-review

96 Scopus citations


The Kaposi's sarcoma-associated herpesvirus produces a 1077 nucleotide noncoding, polyadenylated, exclusively nuclear RNA called PAN that is highly expressed in lytically infected cells. We report that PAN contains a novel post-transcriptional element essential for its abundant accumulation. The element, PAN-ENE (PAN RNA expression and nuclear retention element), increases the efficiency of 3′-end formation in vivo and is sufficient to enhance RNA abundance from an otherwise inefficiently expressed intronless β-globin construct. The PAN-ENE does not concomitantly increase the production of encoded protein. Rather, it retains the unspliced β-globin mRNA in the nucleus. Tethering of export factors can override the nuclear retention of the PAN-ENE, supporting a mechanism whereby the PAN-ENE blocks assembly of an export-competent mRNP. The activities of the PAN-ENE are specific to intronless constructs, since inserting the PAN-ENE into a spliced β-globin construct has no effect on mRNA abundance and does not affect localization. This is the first characterization of a cis-acting element that increases RNA abundance of intronless transcripts but inhibits assembly of an export-competent mRNP.

Original languageEnglish (US)
Pages (from-to)1831-1841
Number of pages11
JournalEMBO Journal
Issue number10
StatePublished - May 18 2005


  • 3′-end formation
  • KSHV
  • Nuclear retention
  • PAN
  • RNA export

ASJC Scopus subject areas

  • General Neuroscience
  • Molecular Biology
  • General Biochemistry, Genetics and Molecular Biology
  • General Immunology and Microbiology


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