title: Involvement of the proteasome and antizyme in ornithine decarboxylase degradation by a reticulocyte lysate.
abstract: Ornithine decarboxylase (ODC) degradation in a freshly prepared reticulocyte lysate was examined. Immunodepletion of proteasomes from the reticulocyte lysate resulted in almost complete loss of ODC degradation. In contrast with the previously reported degradation in extracts of hepatoma tissue-culture (HTC) and Chinese-hamster ovary (CHO) cells or that by the purified 26 S proteasome, efficient degradation of ODC was observed in the lysate without exogenous antizyme, an ODC protein inhibitor induced by polyamines, owing to the presence of a significant amount of antizyme in the lysate. The degradation of ODC in the lysate was strongly suppressed on inactivation of antizyme in the lysate with antizyme inhibitor, a protein which binds to the antizyme and releases ODC from the ODC-antizyme complex. Thus the main pathway for ODC degradation in a reticulocyte lysate was essentially the same as that characterized previously in extracts of HTC and CHO cells, namely an ATP- and antizyme-dependent 26 S proteasome-catalysed pathway that is presumed to be responsible for ODC degradation in whole cells.
authors.affiliation: Department of Nutrition, Jikei University School of Medicine, Tokyo, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Murakami
authors.forename: S
authors.initials: S
authors.lastname: Matsufuji
authors.forename: K
authors.initials: K
authors.lastname: Tanaka
authors.forename: A
authors.initials: A
authors.lastname: Ichihara
authors.forename: S
authors.initials: S
authors.lastname: Hayashi
mesh_terms: D000818:Animals; D002352:Carrier Proteins; D002474:Cell-Free System; D003546:Cysteine Endopeptidases / Q000378:metabolism*; D051379:Mice; D009097:Multienzyme Complexes / Q000378:metabolism*; D009955:Ornithine Decarboxylase / Q000378:metabolism*; D065108:Ornithine Decarboxylase Inhibitors; D046988:Proteasome Endopeptidase Complex; D011506:Proteins / Q000378:metabolism* / Q000494:pharmacology*; D011817:Rabbits; D012156:Reticulocytes / Q000378:metabolism*
chemical_list: D002352:Carrier Proteins; D009097:Multienzyme Complexes; D065108:Ornithine Decarboxylase Inhibitors; D011506:Proteins; C031017:ornithine decarboxylase antizyme; C039317:ornithine decarboxylase antizyme inhibitor; D003546:Cysteine Endopeptidases; D046988:Proteasome Endopeptidase Complex; D009955:Ornithine Decarboxylase