Poster abstracts

Poster number 64 submitted by Mohd M. Khan

Endothelin1 mRNA Is Posttranscriptionally Regulated By Glyceraldehyde-3-phosphate Dehydrogenase: Role In Cardiovascular Diseases

Mohd M. Khan (Univ of Maryland at Baltimore County, Baltimore, MD), John Chavis (Univ of Maryland at Baltimore County, Baltimore, MD), Beth E. Zucconi (Univ of Maryland School of Medicine, Baltimore, MD), Jacob P. Neal (Univ of Maryland at Baltimore County, Baltimore, MD), Gerald M. Wilson (Univ of Maryland School of Medicine, Baltimore, MD), Elsa D. Garcin (Univ of Maryland at Baltimore County, Baltimore, MD)

Abstract:
Regulation of Endothelin-1, the most potent vasoconstrictor, has a pathophysiological importance in cardiovascular diseases (hypertension, coronary heart diseases, congestive heart failure, and atherosclerosis), pulmonary diseases (asthma and hypertension), central nervous system diseases (Hirschprung’s disease, stroke and subarachnoid hemorrhage), and eye diseases (diabetic retinopathy and glaucoma). Glyceraldehyde-3-phosphate dehydrogenase (GAPDH), a glycolytic enzyme, can bind to the adenine-uridine rich elements (AREs) in the 3’untranslated region (3’UTR) of Endothelin-1 (ET1) mRNA, destabilize its mRNA, and leads to decreased ET1 protein levels. Pathophysiological implications of ET1 dysregulation have been treated clinically by targeting ET1 receptors or ET1 processing proteases. GAPDH-mediated regulation of ET1 mRNA stability offers an alternative therapeutic intervention. However, the molecular mechanism by which GAPDH binds to and destabilizes ET1 mRNA is unknown. GAPDH does not contain sequence homology to RNA recognition domain like other reported AdenineUridine binding proteins (AUBPs), however our preliminary studies suggest that GAPDH may contain a classical RRM like structural motif that could be involved in RNA binding.

We aim to determine the specific interactions between GAPDH and ET1 mRNA, by using mutagenesis, RNA electrophoretic mobility shift assay (REMSA), fluorescence anisotropy, molecular modeling, and xray crystallography.

We will use this structural information to guide structure based drug design of small molecules aimed at destabilizing ET1 mRNA and controlling cellular ET1 protein levels to treat cardiovascular diseases.

References:
J. Cardiovasc. Res. (2007) 76, 8–18
The FASEB Journal (2011) 25, 16–28
Bioorg Med Chem Lett. (2000) 10, 2037-9
J Cardiovasc Pharmacol (2000) 36, S36-9
Mol. Cell. Biol. (2008) 28, 7139–7155
Biochem. J. (2005) 387, 763-772
J Neurochem. (2003) 85:1228
Cell Signal. (2011) 2392:317-323
Science (1994) 265, 615-621
J. Biol. Chem. (2004) 279(10), 8655–67
J. Biol. Chem. (1995) 270, 2755–2763
Nat. Chem. Biol. (2008) 4, 700-707
J. Biol. Chem. (2005) 280, 22406-22417

Keywords: Endothelin-1, RNA, vasoconstriction, post-transcriptional regulation, heart diseases, RRM motifs, adenine-uridine rich elements (AREs)