1. Determination of cell survival by RING-mediated regulation of inhibitor of apoptosis (IAP) protein abundance
- Author
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Miha Pakusch, Paul G Ekert, Tobias Kratina, David L. Vaux, Catherine L. Day, David C.S. Huang, Diep Chu, and John Silke
- Subjects
Proteasome Endopeptidase Complex ,Cell Survival ,Ubiquitin-Protein Ligases ,Molecular Sequence Data ,Apoptosis ,X-Linked Inhibitor of Apoptosis Protein ,Inhibitor of apoptosis ,Cell Line ,Inhibitor of Apoptosis Proteins ,Ubiquitin ,Homeostasis ,Amino Acid Sequence ,Melanoma ,Inhibitor of apoptosis domain ,Multidisciplinary ,biology ,Biological Sciences ,Protein Structure, Tertiary ,Ubiquitin ligase ,Cell biology ,XIAP ,body regions ,Biochemistry ,Proteasome ,Caspases ,biology.protein ,Baculoviral IAP repeat-containing protein 3 ,Cisplatin - Abstract
Inhibitor of apoptosis (IAP) proteins, which bind to caspases via their baculoviral IAP repeat domains, also bear RING domains that enable them to promote ubiquitylation of themselves and other interacting proteins. Here we show that the RING domain of cIAP1 allows it to bind directly to the RING of X-linked IAP, causing its ubiquitylation and degradation by the proteasome, thus revealing a mechanism by which IAPs can regulate their abundance. Expression of a construct containing the RING of cellular IAP1 was able to deplete melanoma cells of endogenous X-linked IAP, promoted apoptosis, and also markedly reduced their clonogenicity when treated with cisplatin. Cross control of protein levels by RING domains may therefore enable their levels to be manipulated therapeutically.
- Published
- 2005