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Updated: Jul 5, 2026

Combining Mitotic Cell Synchronization and High Resolution Confocal Microscopy to Study the Role of Multifunctional Cell Cycle Proteins During Mitosis
08:33

Combining Mitotic Cell Synchronization and High Resolution Confocal Microscopy to Study the Role of Multifunctional Cell Cycle Proteins During Mitosis

Published on: December 5, 2017

Triggering the all-or-nothing switch into mitosis

P H O'Farrell1

  • 1Dept of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA 94143-0448, USA. ofarrell@cgl.ucsf.edu

Trends in Cell Biology
|November 24, 2001
PubMed

Insights

Cell cycle research reveals a key switch mechanism controlling entry into mitosis. This switch rapidly removes inhibitory phosphates from cyclin:Cdk1 complexes, committing the cell to division.

Area of Science:

  • Cell Biology
  • Molecular Biology
  • Biochemistry

Background:

  • The cell cycle is tightly regulated to ensure proper cell division.
  • Entry into mitosis involves the activation of key regulatory kinases.
  • Multiple regulatory mechanisms modulate kinase activity, including phosphorylation and inhibitor binding.

Purpose of the Study:

  • To elucidate the primary regulatory mechanism controlling the G2 to mitosis transition.
  • To understand the switch-like process that commits cells to mitosis.

Main Methods:

  • Review of cell cycle investigations over the past decade.
  • Analysis of regulatory pathways modulating cyclin:Cdk1 complexes.
  • Focus on phosphorylation and dephosphorylation events.

Main Results:

  • A specific regulatory option, rather than a combination, governs the G2 to mitosis transition.
  • A switch-like mechanism integrates cellular status signals.
  • This switch involves the abrupt removal of inhibitory phosphates from preformed cyclin:Cdk1 complexes.

Conclusions:

  • The primary control for entering mitosis relies on a dephosphorylation switch.
  • This switch rapidly activates mitotic kinase by altering the balance of modifying reactions.
  • This mechanism ensures a decisive commitment to cell division.

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