Role of phosphorylation of Cdc20 in the regulation of the action of APC/C in mitosis.

The ubiquitin ligase APC/C (anaphase-promoting complex/cyclosome) is essential for the control of mitosis, and its activity is subject to tight regulation. In early mitosis, APC/C is inhibited by the mitotic checkpoint system, but subsequently it regains activity and promotes metaphase-anaphase transition by targeting cyclin B and securin for degradation. The phosphorylation of APC/C by the mitotic protein kinase Cdk1-cyclin B facilitates its interaction with its coactivator Cdc20, while the phosphorylation of Cdc20 inhibits its binding to APC/C.

Role of Polo-like kinase 1 in the regulation of the action of p31 in the disassembly of mitotic checkpoint complexes.

The Mad2-binding protein p31 has important roles in the inactivation of the mitotic checkpoint system, which delays anaphase until chromosomes attach correctly to the mitotic spindle. The activation of the checkpoint promotes the assembly of a Mitotic Checkpoint Complex (MCC), which inhibits the action of the ubiquitin ligase APC/C (Anaphase-Promoting Complex/Cyclosome) to degrade inhibitors of anaphase initiation. The inactivation of the mitotic checkpoint requires the disassembly of MCC.

Role of ubiquitylation of components of mitotic checkpoint complex in their dissociation from anaphase-promoting complex/cyclosome.

The mitotic checkpoint system ensures the fidelity of chromosome segregation in mitosis by preventing premature initiation of anaphase until correct bipolar attachment of chromosomes to the mitotic spindle is reached. It promotes the assembly of a mitotic checkpoint complex (MCC), composed of BubR1, Bub3, Cdc20, and Mad2, which inhibits the activity of the anaphase-promoting complex/cyclosome (APC/C) ubiquitin ligase. When the checkpoint is satisfied, anaphase is initiated by the disassembly of MCC.

Role of CCT chaperonin in the disassembly of mitotic checkpoint complexes.

The mitotic checkpoint system prevents premature separation of sister chromatids in mitosis and thus ensures the fidelity of chromosome segregation. When this checkpoint is active, a mitotic checkpoint complex (MCC), composed of the checkpoint proteins Mad2, BubR1, Bub3, and Cdc20, is assembled. MCC inhibits the ubiquitin ligase anaphase promoting complex/cyclosome (APC/C), whose action is necessary for anaphase initiation.

Camellia sinensis in asymptomatic hyperuricemia: A meta-analysis of tea or tea extract effects on uric acid levels.

Flavanols of Camellia sinensis exhibit uric acid (UA) lowering effect, through the modulation of both xanthine oxidase and urate excretion. In order to investigate the potential benefit of Camellia Sinenis products in asymptomatic hyperuricemia, a meta-analysis of long-term Randomized Controlled Trials (RCT) with tea or tea extract has been conducted. From 20 human intervention studies selected only 5 RCT (13 interventions) were suitable for meta-analysis (n = 472).