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Published on: November 26, 2011

Cytostatic p21 G protein-activated protein kinase gamma-PAK

J Roig1, J A Traugh

  • 1Department of Biochemistry, University of California, Riverside, Riverside, California 92504, USA.

Vitamins and Hormones
|May 11, 2001
PubMed

Insights

The p21-activated protein kinase gamma-PAK (PAK2) exhibits cytostatic activity and is activated by various cellular stresses. It plays a role in apoptosis and may coordinate stress responses.

Area of Science:

  • Cell Biology
  • Molecular Biology
  • Biochemistry

Background:

  • The p21-activated protein kinase (PAK) family comprises conserved isoforms: alpha-PAK (PAK1), beta-PAK (PAK3), and gamma-PAK (PAK2).
  • gamma-PAK (PAK2) possesses distinct properties compared to PAK1 and PAK3.

Purpose of the Study:

  • To investigate the cytostatic activity of gamma-PAK (PAK2).
  • To identify the stress conditions that activate gamma-PAK (PAK2).
  • To elucidate the role of gamma-PAK (PAK2) in cellular stress responses and apoptosis.

Main Methods:

  • Microinjection of gamma-PAK (PAK2) into frog embryos.
  • Expression of gamma-PAK (PAK2) in mammalian cells.
  • Analysis of gamma-PAK (PAK2) activation pathways under various stress conditions.
  • Investigation of gamma-PAK (PAK2) cleavage by caspase 3 during apoptosis.

Main Results:

  • gamma-PAK (PAK2) demonstrated cytostatic activity, inhibiting embryonic development and cell growth.
  • gamma-PAK (PAK2) activation was observed in response to DNA damage, hyperosmolarity, sphingosine, serum starvation, and contact inhibition.
  • Activation involves phosphoinositide 3-kinase and/or tyrosine kinase pathways.
  • gamma-PAK (PAK2) is cleaved and activated by caspase 3 during apoptosis, suggesting a role in this process.
  • gamma-PAK (PAK2) localizes to the cytosol, membrane, and secretory granules.
  • Numerous substrates for gamma-PAK (PAK2) have been identified.

Conclusions:

  • gamma-PAK (PAK2) exhibits significant cytostatic effects and is a key mediator of cellular stress responses.
  • Its activation pathways and role in apoptosis highlight its importance in cellular homeostasis.
  • gamma-PAK (PAK2) may function in coordinating cellular reactions to diverse stresses.

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