New roles for p21 and p27 cell-cycle inhibitors: a function for each cell compartment?

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Studying Cell Cycle-regulated Gene Expression by Two Complementary Cell Synchronization Protocols
12:02

Studying Cell Cycle-regulated Gene Expression by Two Complementary Cell Synchronization Protocols

Published on: June 6, 2017

Olivier Coqueret1

  • 1INSERM U564, 4 rue Larrey, CHU Angers, France. olivier.coqueret@univ-angers.fr

Trends in Cell Biology
|February 1, 2003
PubMed

Insights

Cell cycle inhibitors p21 and p27 (cyclin-dependent kinase inhibitors) have known roles in cell cycle arrest. Emerging evidence reveals novel functions beyond inhibiting cyclin-dependent kinases (CDKs).

Area of Science:

  • Molecular Biology
  • Cell Biology
  • Biochemistry

Background:

  • Cell division progression is regulated by cyclins and cyclin-dependent kinases (CDKs).
  • Dysregulated CDK activity is a hallmark of human cancers.
  • Cell-cycle inhibitors, p21 and p27 (Cip/Kip proteins), normally inhibit CDK activity to arrest the cell cycle in response to anti-mitogenic signals or DNA damage.

Purpose of the Study:

  • To review recent findings on the non-canonical functions of p21 and p27 Cip/Kip proteins.
  • To explore emerging roles of p21 and p27 beyond their established CDK inhibitory activities.

Main Methods:

  • Literature review of recent discoveries regarding p21 and p27.
  • Analysis of studies identifying new protein targets of p21 and p27.
  • Examination of research on the cytoplasmic localization of p21 and p27.

Main Results:

  • Recent studies suggest p21 and p27 possess novel functions independent of CDK inhibition.
  • Identification of new targets and evidence of cytoplasmic relocalization indicate expanded roles.
  • These proteins are implicated in controlling CDK activation, regulating apoptosis, and transcriptional activation.

Conclusions:

  • p21 and p27 Cip/Kip proteins exhibit multifaceted roles in cellular regulation.
  • Their functions extend beyond cell-cycle arrest to include apoptosis and transcriptional control.
  • Further research into these additional activities is warranted to fully understand their biological significance.

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