Anaphase

Anaphase (from Ancient Greek ἀνα- (ana-) 'back, backward' and φάσις (phásis) 'appearance') is the stage of mitosis after the process of metaphase, when replicated chromosomes are split and the newly-copied chromosomes (daughter chromatids) are moved to opposite poles of the cell.

The destruction of securin unleashes separase which then breaks down cohesin, a protein responsible for holding sister chromatids together.

The first of these, anaphase A, moves chromosomes to either pole of a dividing cell (marked by centrosomes, from which mitotic microtubules are generated and organised).

The attached microtubules depolymerise and shorten, which together with motor proteins creates movement that pulls chromosomes towards centrosomes located at each pole of the cell.

B cyclin is marked with ubiquitin which flags it for destruction by proteasomes, which is required for the function of metaphase cyclin-dependent kinases (M-Cdks).

In essence, Activation of the Anaphase-promoting complex (APC) causes the APC to cleave the M-phase cyclin and the inhibitory protein securin which activates the separase protease to cleave the cohesin subunits holding the chromatids together.