title: Apoptosis induction resulting from proteasome inhibition.
abstract: Proteases are known to be involved in the apoptotic pathway. We report here that benzyloxycarbonyl (Z)-Leu-Leu-leucinal(ZLLLal), a leupeptin analogue, can induce apoptosis in MOLT-4 and L5178Y cells. ZLLLal is a cell-permeant inhibitor of proteasome. Among the protease inhibitors tested, only calpain inhibitor I (acetyl-Leu-Leu-norleucinal) and ZLLLal caused a marked induction of apoptosis in MOLT-4 cells. In contrast Z-Leu-leucinal, a specific inhibitor of calpain, did not induce apoptosis. When MOLT-4 cells were incubated in the presence of ZLLLal, p53 accumulated in the cells. These results strongly suggest that inhibition of proteasome induces p53-dependent apoptosis and that proteasome can protect cell from apoptosis.
authors.affiliation: Department of Radiation Research, Tokyo Metropolitan Institute of Medical Science, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Shinohara
authors.forename: M
authors.initials: M
authors.lastname: Tomioka
authors.forename: H
authors.initials: H
authors.lastname: Nakano
authors.forename: S
authors.initials: S
authors.lastname: Toné
authors.forename: H
authors.initials: H
authors.lastname: Ito
authors.forename: S
authors.initials: S
authors.lastname: Kawashima
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects* / Q000528:radiation effects; D003546:Cysteine Endopeptidases / Q000187:drug effects*; D015853:Cysteine Proteinase Inhibitors / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D006801:Humans; D007976:Leupeptins / Q000494:pharmacology*; D051379:Mice; D009097:Multienzyme Complexes / Q000187:drug effects*; D046988:Proteasome Endopeptidase Complex; D014407:Tumor Cells, Cultured; D016159:Tumor Suppressor Protein p53 / Q000032:analysis; D014965:X-Rays
chemical_list: D015853:Cysteine Proteinase Inhibitors; D007976:Leupeptins; D009097:Multienzyme Complexes; D016159:Tumor Suppressor Protein p53; D003546:Cysteine Endopeptidases; D046988:Proteasome Endopeptidase Complex; C072553:benzyloxycarbonylleucyl-leucyl-leucine aldehyde