Nucleic Acids Research Advance Access published online on February 26, 2009
Nucleic Acids Research, doi:10.1093/nar/gkp098
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Gene Regulation, Chromatin and Epigenetics |
Posttranscriptional regulation of angiotensin II type 1 receptor expression by glyceraldehyde 3-phosphate dehydrogenase
1Biomedicum Helsinki and Department of Medicine, University of Helsinki, Helsinki, Finland, 2Hybrigenics SA, 3-5 Impasse Reille, 75014 Paris, France, 3Department of Cardiology, University Medical Center Groningen, Groningen, Netherlands, 4Computational Systems Biology Laboratory, Institute of Biomedicine and Genome-Scale Biology Research Program, 5Protein Chemistry Research Group, Institute of Biotechnology, University of Helsinki, Finland, 6Tufts-New England Medical Center, Boston, MA 02111, USA and 7Department of Cardiology, Helsinki University Central Hospital, Helsinki, Finland
*To whom correspondence should be addressed. Tel: +358 9 471 71920; Fax: +358 9 471 71921; Email: jukka.lehtonen{at}hus.fi
Received November 13, 2008. Revised February 4, 2009. Accepted February 6, 2009.
Regulation of angiotensin II type 1 receptor (AT1R) has a pathophysiological role in hypertension, atherosclerosis and heart failure. We started from an observation that the 3'-untranslated region (3'-UTR) of AT1R mRNA suppressed AT1R translation. Using affinity purification for the separation of 3'-UTR-binding proteins and mass spectrometry for their identification, we describe glyceraldehyde 3-phosphate dehydrogenase (GAPDH) as an AT1R 3'-UTR-binding protein. RNA electrophoretic mobility shift analysis with purified GAPDH further demonstrated a direct interaction with the 3'-UTR while GAPDH immunoprecipitation confirmed this interaction with endogenous AT1R mRNA. GAPDH-binding site was mapped to 1–100 of 3'-UTR. GAPDH-bound target mRNAs were identified by expression array hybridization. Analysis of secondary structures shared among GAPDH targets led to the identification of a RNA motif rich in adenines and uracils. Silencing of GAPDH increased the expression of both endogenous and transfected AT1R. Similarly, a decrease in GAPDH expression by H2O2 led to an increased level of AT1R expression. Consistent with GAPDH having a central role in H2O2-mediated AT1R regulation, both the deletion of GAPDH-binding site and GAPDH overexpression attenuated the effect of H2O2 on AT1R mRNA. Taken together, GAPDH is a translational suppressor of AT1R and mediates the effect of H2O2 on AT1R mRNA.
The authors wish it to be known that, in their opinion, the first two authors should be regarded as joint First Authors.