| First Author | Onesto C | Year | 2004 |
| Journal | J Biol Chem | Volume | 279 |
| Issue | 33 | Pages | 34217-26 |
| PubMed ID | 15175342 | Mgi Jnum | J:92234 |
| Mgi Id | MGI:3052248 | Doi | 10.1074/jbc.M400219200 |
| Citation | Onesto C, et al. (2004) Poly(A)-binding protein-interacting protein 2, a strong regulator of vascular endothelial growth factor mRNA. J Biol Chem 279(33):34217-26 |
| abstractText | Expression of vascular endothelial growth factor (VEGF) is tightly regulated, particularly at the level of its mRNA stability, which is essentially mediated through the 3'-untranslated region (3'-UTR) of VEGF mRNA. To identify new protein partners regulating VEGF mRNA stability, we screened a cDNA expression library with an RNA probe corresponding to the entire VEGF mRNA 3'-UTR. We identified the 'poly(A)-binding protein-interacting protein 2' (PAIP2) as a new VEGF mRNA 3'-UTR interacting protein. By RNA electromobility shift assays, we showed that PAIP2 binds to two distinct regions of a domain encompassing base 1 to 1280 of the VEGF 3'-UTR. Such in vitro interaction was confirmed using cell extracts in which PAIP2 expression is induced by tetracycline (Tet-on cells). Moreover, we demonstrated by RNA affinity purification as well as by ribonucleoprotein complexes immunoprecipitation, that PAIP2 interacts with VEGF mRNA in vivo. Using an in vitro RNA degradation assay, the half-life of VEGF 3'-UTR was found to be increased by overexpressing PAIP2. PAIP2 stabilizes endogenous VEGF mRNA in Tet-on cells, leading to increased VEGF secretion. Moreover, RNAi-mediated knock-down of PAIP2 significantly reduces the steady-state levels of endogenous VEGF mRNA. We also showed, by in vitro protein-protein interactions and co-immunoprecipitation experiments, that PAIP2 interacts with HuR, an already known VEGF mRNA-binding protein, suggesting cooperation of both proteins for VEGF mRNA stabilization. Hence, PAIP2 appears to be a crucial regulator of VEGF mRNA and as a consequence, any variation in its expression could modulate angiogenesis. |
