Specific trans-acting proteins interact with auxiliary RNA polyadenylation elements in the COX-2 3′-UTR

Tyra Hall-Pogar, Songchun Liang, Lisa K. Hague, Carol S. Lutz

Research output: Contribution to journalArticlepeer-review

70 Scopus citations


Two cyclooxygenase (COX) enzymes, COX-1 and COX-2, are present in human cells. While COX-1 is constitutively expressed, COX-2 is inducible and up-regulated in response to many signals. Since increased transcriptional activity accounts for only part of COX-2 up-regulation, we chose to explore other RNA processing mechanisms in the regulation of this gene. Previously, we showed that COX-2 is regulated by alternative polyadenylation, and that the COX-2 proximal polyadenylation signal contains auxiliary upstream sequence elements (USEs) that are very important in efficient polyadenylation. To explore trans-acting protein factors interacting with these cis-acting RNA elements, we performed pull-down assays with HeLa nuclear extract and biotinylated RNA oligonucleotides representing COX-2 USEs. We identified PSF, p54nrb, PTB, and U1A as proteins specifically bound to the COX-2 USEs. We further explored their participation in polyadenylation using MS2 phage coat protein-MS2 RNA binding site tethering assays, and found that tethering any of these four proteins to the COX-2 USE mutant RNA can compensate for these cis-acting elements. Finally, we suggest that these proteins (p54nrb, PTB, PSF, and U1A) may interact as a complex since immunoprecipitations of the transfected MS2 fusion proteins coprecipitate the other proteins. Published by Cold Spring Harbor Laboratory Press.

Original languageEnglish (US)
Pages (from-to)1103-1115
Number of pages13
Issue number7
StatePublished - Jul 2007

All Science Journal Classification (ASJC) codes

  • Molecular Biology


  • 3′-untranslated region (UTR)
  • Cyclooxygenase-2 (COX-2)
  • Polyadenylation


Dive into the research topics of 'Specific trans-acting proteins interact with auxiliary RNA polyadenylation elements in the COX-2 3′-UTR'. Together they form a unique fingerprint.

Cite this