Two-Step Mechanism of Cyclin B Degradation Initiated by Proteolytic Cleavage with the 26 S Proteasome in Fish.

ABSTRACT: To complete meiosis II, cyclin B is degraded in a short period by the inactivation of M-phase promoting factor (MPF). Previously, we showed that the destruction of cyclin B was initiated by the ubiquitin-independent proteolytic activity of the 26 S proteasome through an initial cut in the N-terminus of cyclin (at K57 in the case of goldfish cyclin B). We hypothesized that this cut allows cyclin to be ubiquitinated for further destruction by the ubiquitin-dependent proteolytic pathway, which leads to MPF inactivation. In this study, we aimed to identify the ubiquitination site for further degradation. The destruction of cyclin B point mutants in which lysine residues in a lysine-rich stretch following the cut site of cyclin B had been mutated was analyzed. All the lysine point mutants excep

SUBMITTER: Tokumoto T 

PROVIDER: S-EPMC7265292 | biostudies-literature | 2020 Jun

REPOSITORIES: biostudies-literature