Glyceraldehyde-3-Phosphate Dehydrogenase Regulates Endothelin-1 Expression by a Novel, Redox-Sensitive Mechanism Involving mRNA Stability

Abstract

The regulation of the synthesis of the endothelial-derived vasoconstrictor endothelin-1 (ET-1) is a complex process encompassing transcriptional as well as mRNA stability mechanisms. We have described recently the existence of a mechanism for the control of ET-1 expression based on the mRNA-destabilizing capacity of specific cytosolic proteins through interaction with AU-rich elements (AREs) present in the 3 untranslated region of the gene. We now identify glyceraldehyde-3-phosphate dehydrogenase (GAPDH) as a protein which binds to the AREs and is responsible for the destabilization of the mRNA. Oxidant stress alters the binding of GAPDH to the mRNA and its capacity to modulate ET-1 expression, a phenomenon occurring through specific S glutathionylation of the catalytically active residue Cys 152. Finally, we provide data consistent with a role for GAPDH in mRNA unwinding, yielding this molecule more prone to degradation. In contrast, S-thiolated GAPDH appears unable to modify mRNA unwinding, thus facilitating enhanced stability. Taken together, these results describe a novel, redox-based mechanism regulating mRNA stability and add a new facet to the panoply of GAPDH cellular homeostatic actions.The endothelium contributes greatly to vascular homeostasis by functioning as a sensor of physical and chemical stimuli and responding to them with specific signals. Vascular tone and blood pressure are regulated by endothelial cells through a tight balance of the levels of vasodilator and vasoconstrictor substances, the most important being nitric oxide (NO) and endothelin-1 (ET-1), respectively. In addition to its constrictor action, ET-1 has been shown to be involved in normal tissue repair and also in the pathogenesis of fibrotic diseases (38). All of these ET-1 biological actions can lead to pathophysiological processes under certain circumstances. In this respect, elevated circulating and tissue ET-1 levels have been measured in patients suffering from certain vascular diseases, such as atherosclerosis, pulmonary hypertension, or skin and lung fibrosis (2, 32). Therefore, ET-1 production and secretion by vascular endothelial cells must be tightly regulated. Endothelial cells synthesize ET-1 as a propeptide of 212 residues, preproendothelin-1, which is then subjected to specific proteolysis to yield the bioactive ET-1 peptide of 21 amino acids. The regulation of the expression is a complex process that occurs mainly at the mRNA level and involves both transcriptional and posttranscriptional mechanisms (26,27,31,45). Although the analysis of the transcription of the gene has attracted most of the attention, posttranscriptional mechanisms have recently been revealed as essential steps in the regulation of the biosynthesis (37, 43).Generally speaking, many of the processes dealing with specific regulatory mechanisms at the posttranscriptional level take place within genetic elements present in the 3Ј untranslated region (3Ј UTR) of the genes (10,17,20). Adenine-and uridine-rich elements (AREs), which are often found in...

LOXL4 Is Induced by Transforming Growth Factor β1 through Smad and JunB/Fra2 and Contributes to Vascular Matrix Remodeling

“…Smad3 knockout and wild-type embryonic fibroblasts (MEF) were isolated from newborn mice and kept in culture using standard procedures (13). Tetracycline (Tet)-inducible human embryonic kidney 293 (HEK 293) cells stably expressing LOXL4-green fluorescent protein (GFP) constructs were generated and maintained in culture according to protocols previously published (14).…”

Nuclear GAPDH: changing the fate of Müller cells in diabetes

“…Through such interaction, it may stabilize or destabilize the mRNA it is associated with. While GAPDH destabilizes the mRNA of endothelial vasoconstrictor ET-1 via its interaction and eventual mRNA degradation [35], GAPDH stabilizes the mRNA of the hematopoietic cytokine colony stimulating factor 1 [36,37]. GAPDH also interacts with the angiotensin II type 1 receptor (AT1R) mRNA [38] and decreases the AT1R translation but does not degrade the AT1R mRNA.…”

Redox Signaling in Cardiac Physiology and Pathology

“…45 Another redoxregulated function of GAPDH is to control mRNA stabilization. 46 GAPDH binds the 3′ untranslated region of endothelin-1 mRNA and enhances degradation by destabilizing it. However, when GAPDH is S-glutathionylated during oxidant stress at its catalytic Cys-152, this decreases mRNA binding to promote stabilization and enhance protein expression.…”