positive regulation of mitotic metaphase/anaphase transition

Definition

Target type: biologicalprocess

Any process that activates or increases the frequency, rate or extent of the cell cycle process in which a cell progresses from metaphase to anaphase during mitosis, triggered by the activation of the anaphase promoting complex by Cdc20/Sleepy homolog which results in the degradation of Securin. [GOC:go_curators]

The transition from metaphase to anaphase, a pivotal step in cell division, is tightly controlled by a complex network of proteins and signaling pathways. This transition is positively regulated by the activation of the anaphase promoting complex/cyclosome (APC/C), an E3 ubiquitin ligase. The APC/C, in conjunction with its co-activator Cdc20, targets key regulatory proteins for ubiquitination, leading to their proteasomal degradation.

One of the key targets of APC/C/Cdc20 is securin, a protein that inhibits the separation of sister chromatids. Degradation of securin activates separase, a protease that cleaves cohesin, the protein complex that holds sister chromatids together. This cleavage allows the sister chromatids to separate and move to opposite poles of the cell.

Another crucial target of APC/C/Cdc20 is cyclin B, a regulatory subunit of the cyclin-dependent kinase (CDK) complex that drives mitotic progression. Degradation of cyclin B inactivates the CDK complex, thus allowing the cell to exit mitosis and enter the next cell cycle phase.

The activation of APC/C/Cdc20 is tightly regulated by the spindle assembly checkpoint (SAC). The SAC ensures that all chromosomes are correctly attached to the spindle microtubules before allowing the cell to proceed into anaphase.

In summary, positive regulation of mitotic metaphase/anaphase transition is achieved by a series of events that are coordinated by the APC/C/Cdc20 complex. This complex targets key regulatory proteins for degradation, leading to the activation of separase, the inactivation of the CDK complex, and ultimately, the separation of sister chromatids and the progression of the cell cycle.'
"

Proteins (2)

Compounds (2)