title: Native structure of rat liver immune proteasomes.
abstract: Native structure of active forms of rat liver immune proteasomes has been studied by two-dimensional electrophoresis method modified for analysis of unpurified protein fractions. The developed method allowed revealing the proteasome immune subunits LMP7 and LMP2 in 20S subparticles and in the structures bound to one or two PA28αβ activators, but not to the PA700 activator, which is involved in the hydrolysis of ubiquitinated proteins. The results obtained indicate the participation of the immune proteasomes in delicate regulatory mechanisms based on the production of biologically active peptides and exclude their participation in processes of crude degradation of "rotated" ubiquitinated proteins.
authors.affiliation: Koltzov Institute of Developmental Biology, Russian Academy of Sciences, ul. Vavilova 26, Moscow, 119334, Russia.
authors.forename: A A
authors.initials: AA
authors.lastname: Stepanova
authors.affiliation: Koltzov Institute of Developmental Biology, Russian Academy of Sciences, ul. Vavilova 26, Moscow, 119334, Russia.
authors.forename: Yu V
authors.initials: YV
authors.lastname: Lyupina
authors.affiliation: Koltzov Institute of Developmental Biology, Russian Academy of Sciences, ul. Vavilova 26, Moscow, 119334, Russia. npsharova@bk.ru.
authors.forename: N P
authors.initials: NP
authors.lastname: Sharova
authors.affiliation: Koltzov Institute of Developmental Biology, Russian Academy of Sciences, ul. Vavilova 26, Moscow, 119334, Russia.
authors.forename: P A
authors.initials: PA
authors.lastname: Erokhov
mesh_terms: D015153:Blotting, Western; D018797:Cell Cycle Proteins; D003546:Cysteine Endopeptidases / Q000737:chemistry / Q000378:metabolism*; D015180:Electrophoresis, Gel, Two-Dimensional / Q000379:methods; D008099:Liver / Q000201:enzymology* / Q000276:immunology*; D046988:Proteasome Endopeptidase Complex / Q000737:chemistry* / Q000378:metabolism*; D011487:Protein Conformation; D011506:Proteins / Q000737:chemistry / Q000378:metabolism
chemical_list: D018797:Cell Cycle Proteins; C085834:PA700 proteasome activator; D011506:Proteins; C490050:Psme1 protein, rat; C490052:Psme2 protein, rat; C071313:LMP-2 protein; D003546:Cysteine Endopeptidases; C077436:LMP7 protein; D046988:Proteasome Endopeptidase Complex