Apollon (Q9NR09) is a ~500 kDa membrane associated inhibitor of apoptosis (IAP) protein. It encodes baculoviral-IAP-repeat (BIR) and ubiquitin-conjugating enzyme (UBC) domains at the N and C-termini, respectively. Unlike other IAPs Apollon encodes a chimeric E2/E3 ubiquitin ligase and is essential for inhibition of apoptosis in certain cell lines. Apollon inhibits apoptosis by promoting ubiquitination and degradation of active Smac and caspase-9, but Apollon also binds to and inactivates precursors of caspase-9 and Smac. Inactivation of Apollon also leads to upregulation and nuclear localization of p53,Which results in activation of caspase-2, Bax, and Bak, ultimately leading to mitochondrial apoptosis.
BIRC6; baculoviral IAP repeat containing 6; baculoviral IAP repeat-containing protein 6; apollon; BRUCE; baculoviral IAP repeat-containing 6; ubiquitin-conjugating BIR domain enzyme apollon; ubiquitin-conjugating BIR-domain enzyme apollon; BIR repeat-containing ubiquitin-conjugating enzyme; FLJ13726; FLJ13786; KIAA1289