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Deprecated: Implicit conversion from float 231.6 to int loses precision in C:\Inetpub\vhosts\kidney.de\httpdocs\pget.php on line 534 Cell 2014 ; 157 (7): 1605-18 Nephropedia Template TP
Eswarappa SM; Potdar AA; Koch WJ; Fan Y; Vasu K; Lindner D; Willard B; Graham LM; DiCorleto PE; Fox PL
Cell 2014[Jun]; 157 (7): 1605-18 PMID24949972show ga
Translational readthrough, observed primarily in less complex organisms from viruses to Drosophila, expands the proteome by translating select transcripts beyond the canonical stop codon. Here we show that vascular endothelial growth factor-A (VEGFA) mRNA in mammalian endothelial cells undergoes programmed translational readthrough (PTR) generating VEGF-Ax, an isoform containing a unique 22-amino acid C-terminus extension. A cis-acting element in the VEGFA 3?UTR serves a dual function, not only encoding the appended peptide, but also directing the PTR by decoding the UGA stop codon as serine. Heterogeneous nuclear ribonucleoprotein (hnRNP) A2/B1 binds this element and promotes readthrough. Remarkably, VEGF-Ax exhibits anti-angiogenic activity in contrast to the pro-angiogenic activity of VEGF-A. Pathophysiological significance of VEGF-Ax is indicated by robust expression in multiple human tissues, but depletion in colon adenocarcinoma. Furthermore, genome-wide analysis revealed AGO1 and MTCH2 as authentic readthrough targets. Overall, our studies reveal a novel protein-regulated PTR event in a vertebrate system.