The inhibitor of apoptosis, cIAP2, functions as a ubiquitin-protein ligase and promotes in vitro monoubiquitination of caspases 3 and 7.
The inhibitor of apoptosis, cIAP2, contains a putative Ring finger motif at the C terminus. Using in vitro ubiquitination assays, we found that the Ring finger of cIAP2 alone possesses intrinsic ubiquitin ligase activity and promotes substrate-independent ubiquitination. It also promotes ubiquitination of caspases 3 and 7 but not caspase-1. The Ring fingers of c-Cbl and Apc11 failed to promote caspase-7 ubiquitination, suggesting that the Ring finger of cIAP2 itself is involved in substrate recognition.
Huang
H k
Hk
Molecular Biology and Virology Laboratory, The Salk Institute for Biological Studies and the Department of Immunology, The Scripps Research Institute, La Jolla, California 92037, USA.
Joazeiro
C A
CA
Bonfoco
E
E
Kamada
S
S
Leverson
J D
JD
Hunter
T
T
D000595:Amino Acid Sequence; D053148:Caspase 3; D053179:Caspase 7; D020169:Caspases / Q000378:metabolism*; D051034:Inhibitor of Apoptosis Proteins; D008025:Ligases / Q000737:chemistry / Q000378:metabolism*; D008969:Molecular Sequence Data; D017386:Sequence Homology, Amino Acid; D044767:Ubiquitin-Protein Ligases; D014452:Ubiquitins / Q000378:metabolism*; D014764:Viral Proteins / Q000737:chemistry / Q000378:metabolism*
D051034:Inhibitor of Apoptosis Proteins; D014452:Ubiquitins; D014764:Viral Proteins; C086430:inhibitor of apoptosis, Nucleopolyhedrovirus; D044767:Ubiquitin-Protein Ligases; D053148:Caspase 3; D053179:Caspase 7; D020169:Caspases; D008025:Ligases