Forgot Password

If you have forgotten your password you can enter your email here and get a temporary password sent to your email.

Phosphorylation of Pak1 by the p35/Cdk5 kinase affects neuronal morphology.

The small GTPase Rac and its effectors, the Pak1 and p35/Cdk5 kinases, have been assigned important roles in regulating cytoskeletal dynamics in neurons. Our previous work revealed that the neuronal p35/Cdk5 kinase associates with Pak1 in a RacGTP-dependent manner, causing hyperphosphorylation and down-regulation of Pak1 kinase activity. We have now demonstrated direct phosphorylation of Pak1 on threonine 212 by the p35/Cdk5 kinase. In neuronal growth cones, Pak1 phosphorylated on Thr-212 localized to actin and tubulin-rich areas, suggesting a role in regulating growth cone dynamics. The expression of a non-phosphorylatable Pak1 mutant (Pak1A212) induced dramatic neurite disorganization. We also observed a strong association between p35/Cdk5 and the Pak1 C-terminal kinase domain. Overall, our data show that in neurons, membrane-associated, active Pak1 is regulated by the p35/Cdk5 kinase both by association and phosphorylation, which is essential for the proper regulation of the cytoskeleton during neurite outgrowth and remodeling.

Pubmed ID: 11604394


  • Rashid T
  • Banerjee M
  • Nikolic M


The Journal of biological chemistry

Publication Data

December 28, 2001

Associated Grants


Mesh Terms

  • Animals
  • Cell Size
  • Cells, Cultured
  • Cerebral Cortex
  • Cyclin-Dependent Kinase 5
  • Cyclin-Dependent Kinases
  • Cytoskeleton
  • Growth Cones
  • Immunohistochemistry
  • Mice
  • Models, Biological
  • Neurons
  • Phosphorylation
  • Protein Structure, Tertiary
  • Protein-Serine-Threonine Kinases
  • Rats
  • Recombinant Fusion Proteins
  • p21-Activated Kinases
  • rac GTP-Binding Proteins