Inhibitors of apoptosis catch ubiquitin.
IAP (inhibitor of apoptosis) proteins are a class of anti-apoptotic regulators characterized by the presence of BIR (baculoviral IAP repeat) domains. Some of the IAPs also possess a RING (really interesting new gene) domain with E3 ubiquitin ligase activity. In this issue of the Biochemical Journal, Blankenship et al. unveil the presence of an UBA (ubiquitin-associated domain) in several IAPs. UBAs in c-IAPs (cellular IAPs) bind to monoubiquitin and ubiquitin chains and are implicated in degradation of c-IAPs by promoting their interaction with proteasomes as well as in regulation of TNF-alpha (tumour necrosis factor-alpha)-induced apoptosis. These novel observations establish IAPs as ubiquitin-interacting proteins and opens up new lines of investigation.
Rajalingam
Krishnaraj
K
Emmy Noether Group of the DFG, Goethe University Medical School, Theodor-Stern-Kai 7, D-60590 Frankfurt, Germany.
Dikic
Ivan
I
D006801:Humans; D051034:Inhibitor of Apoptosis Proteins / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000378:metabolism*; D016328:NF-kappa B / Q000378:metabolism; D046988:Proteasome Endopeptidase Complex / Q000378:metabolism; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D025801:Ubiquitin / Q000378:metabolism*
D051034:Inhibitor of Apoptosis Proteins; D016328:NF-kappa B; D025801:Ubiquitin; D046988:Proteasome Endopeptidase Complex