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Blastomere Explants to Test for Cell Fate Commitment During Embryonic Development
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Published on: January 26, 2013

Xenopus p21-activated kinase 5 regulates blastomeres' adhesive properties during convergent extension movements

Sandrine Faure1, Julien Cau, Pascal de Santa Barbara

  • 1Centre de Recherches en Biochimie Macromoléculaire, FRE 2593 CNRS, 34293 Montpellier, France.

Developmental Biology
|December 25, 2004
PubMed

Insights

The p21-activated kinase 5 (X-PAK5) regulates cell movements during Xenopus gastrulation by controlling cell adhesion. This kinase modulates calcium-mediated cell-cell adhesion, impacting embryonic development.

Area of Science:

  • Developmental Biology
  • Cell Biology
  • Molecular Biology

Background:

  • p21-activated kinase (PAK) proteins are crucial regulators of cellular processes, including cytoskeleton dynamics and cell motility.
  • X-PAK5, a previously identified PAK protein, interacts with actin and microtubule networks, suggesting a role in coordinating cellular movements.

Purpose of the Study:

  • To investigate the functional role of X-PAK5 during gastrulation in Xenopus embryos.
  • To elucidate the molecular mechanisms by which X-PAK5 influences cell movements and adhesion during embryonic development.

Main Methods:

  • Expression of wild-type and kinase-dead X-PAK5 mutants in Xenopus embryos and activin-treated animal caps.
  • Analysis of convergent extension movements and cell reassociation assays.
  • Immunolocalization of X-PAK5 and adherens junction proteins, and assessment of calcium's effect on kinase activity.

Main Results:

  • X-PAK5 is predominantly expressed in embryonic regions undergoing significant cell migration during gastrulation.
  • Expression of kinase-dead X-PAK5 inhibits convergent extension movements by altering cell behavior and adhesion.
  • Active X-PAK5 reduces cell adhesiveness and inhibits calcium-dependent cell reassociation, while dead X-PAK5 localizes to cell junctions and increases adhesion.

Conclusions:

  • X-PAK5 plays a critical role in regulating convergent extension movements during Xenopus gastrulation.
  • The kinase modulates cell-cell adhesion through a calcium-mediated mechanism, influencing cell behavior during embryonic development.

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