| First Author | Wilkinson JC | Year | 2004 |
| Journal | J Biol Chem | Volume | 279 |
| Issue | 49 | Pages | 51091-9 |
| PubMed ID | 15371430 | Mgi Jnum | J:114119 |
| Mgi Id | MGI:3688355 | Doi | 10.1074/jbc.M409623200 |
| Citation | Wilkinson JC, et al. (2004) VIAF, a conserved inhibitor of apoptosis (IAP)-interacting factor that modulates caspase activation. J Biol Chem 279(49):51091-9 |
| abstractText | Inhibitor of apoptosis (IAP) proteins are involved in the suppression of apoptosis, signal transduction, cell cycle control and gene regulation. Here we describe the cloning and characterization of viral IAP-associated factor (VIAF), a highly conserved, ubiquitously expressed phosphoprotein with limited homology to members of the phosducin family that associates with baculovirus Op-IAP. VIAF bound Op-IAP both in vitro and in intact cells, with each protein displaying a predominantly cytoplasmic localization. VIAF lacks a consensus IAP binding motif, and overexpression of VIAF failed to prevent Op-IAP from protecting human cells from a variety of apoptotic stimuli, suggesting that VIAF does not function as an IAP antagonist. VIAF was unable to directly inhibit caspase activation in vitro and a reduction of VIAF protein levels by RNA interference led to a decrease in Bax-mediated caspase activation, suggesting that VIAF functions to co-regulate the apoptotic cascade. Finally, VIAF is a substrate for ubiquitination mediated by Op-IAP. Thus, VIAF is a novel IAP-interacting factor that functions in caspase activation during apoptosis. |
