The mpf protein complex turns itself off by

By activating a process that destroys cyclin components, the MPF protein complex turns itself off.
The MPF protein or the Maturation or Mitosis Promoting Factor depending on who you ask is an intricate word for the cyclin B/ CDK1 complex, which is present in the M phase, it is required in order for the entry to the M phase.

Pro insulin undergoes extensive posttranslational modification along the production pathway .

Amutation is basically the change in the gene, caused by alteration of single based units in the dna, or the genes or chromosomes were rearranged in the dna