exit from mitosis

Definition

Target type: biologicalprocess

The cell cycle transition where a cell leaves M phase and enters a new G1 phase. M phase is the part of the mitotic cell cycle during which mitosis and cytokinesis take place. [GOC:dph, GOC:tb]

Exit from mitosis is a tightly regulated process that ensures proper chromosome segregation and the formation of two daughter cells. It involves a series of events that reverse the changes that occurred during prophase, prometaphase, and metaphase.

1. **Cytokinesis:** This process physically separates the two daughter cells. In animal cells, it involves the formation of a contractile ring made of actin filaments and myosin II. This ring contracts, pinching the cell membrane inwards and eventually dividing the cytoplasm. In plant cells, cytokinesis occurs through the formation of a cell plate in the middle of the cell, which eventually develops into a new cell wall.

2. **Depolymerization of the mitotic spindle:** The microtubules of the mitotic spindle begin to depolymerize, dismantling the structure that was responsible for chromosome segregation.

3. **Decondensation of chromosomes:** The condensed chromosomes relax back into their interphase form, making the DNA accessible for transcription and other cellular processes.

4. **Reassembly of the nuclear envelope:** The fragments of the nuclear envelope that were broken down during prophase reassemble around each chromosome set, forming two separate nuclei.

5. **Reformation of the nucleolus:** The nucleolus, which is the site of ribosome biogenesis, reforms within each nucleus.

6. **Downregulation of mitotic cyclins:** The proteins that drive the cell cycle, known as cyclins, are degraded. This ensures that the cell does not prematurely enter another round of mitosis.

7. **Reactivation of cell growth and differentiation pathways:** Once mitosis is complete, the cell can resume its normal growth and differentiation processes.

These events are coordinated by a complex network of signaling pathways and protein interactions, ensuring that the process is accurate and efficient. Exit from mitosis is critical for maintaining the integrity of the genome and ensuring proper cell division.'
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Proteins (1)

Compounds (2)