at what stage of the cell cycle is the cyclin component of mpf destroyed?

MPF (maturation-promoting factor) is destroyed as the cell transitions from mitosis to the next interphase, specifically toward the end of mitosis during the metaphase-to-anaphase window. This destruction occurs because the APC/C (anaphase-promoting complex/cyclosome) ubiquitinates the M-phase cyclin component of MPF (the M cyclin, such as cyclin B), targeting it for proteasomal degradation. With the cyclin component degraded, MPF activity falls sharply, allowing the cell to exit mitosis and proceed into G1. In short: MPF destruction happens late in mitosis, regulated by APC/C, leading to inactivation of MPF.