title: X-linked inhibitor of apoptosis protein mediates neddylation by itself but does not function as a NEDD8-E3 ligase for caspase-7.
abstract: X-linked inhibitor of apoptosis protein (XIAP) is a potent antagonist of caspases, and functions as a ubiquitin-E3 ligase by itself and for caspases. Recently, NEDD8, a ubiquitin-like modifier, has been suggested to be used for modification of caspase-7 mediated by XIAP. However, it is not clear whether caspase-7 is a bona fide target for NEDD8. Here we showed that no neddylation of caspase-7 but that of XIAP itself was observed under the conditions in which caspase-7 was modified with ubiquitin. These results reveal that XIAP does not function as a NEDD8-E3 ligase for caspase-7 in vivo.
authors.affiliation: Biosignal Research Center, Kobe University, Kobe 657-8501, Japan.
authors.forename: Taiki
authors.initials: T
authors.lastname: Nagano
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Hashimoto
authors.forename: Akio
authors.initials: A
authors.lastname: Nakashima
authors.forename: Ushio
authors.initials: U
authors.lastname: Kikkawa
authors.forename: Shinji
authors.initials: S
authors.lastname: Kamada
mesh_terms: D053179:Caspase 7 / Q000378:metabolism*; D057809:HEK293 Cells; D006801:Humans; D000075687:NEDD8 Protein; D025801:Ubiquitin / Q000378:metabolism; D044767:Ubiquitin-Protein Ligases / Q000378:metabolism*; D054875:Ubiquitination; D014452:Ubiquitins / Q000378:metabolism*; D051636:X-Linked Inhibitor of Apoptosis Protein / Q000378:metabolism*
chemical_list: D000075687:NEDD8 Protein; C082860:NEDD8 protein, human; D025801:Ubiquitin; D014452:Ubiquitins; D051636:X-Linked Inhibitor of Apoptosis Protein; D044767:Ubiquitin-Protein Ligases; D053179:Caspase 7