Identification of a common protein association region in the neuronal Cdk5 activator

J Biol Chem. 2000 Oct 13;275(41):31763-9. doi: 10.1074/jbc.M004358200.


Cyclin-dependent protein kinase 5 (Cdk5) depends on the association with neuronal Cdk5 activator (Nck5a) for kinase activity. A variety of cellular proteins have been shown to undergo high affinity association with Nck5a, including three novel proteins, C42, C48, and C53 found by a yeast two-hybrid screen (Ching, Y. P., Qi, Z., and Wang, J. H. (2000) Gene 242, 285-294). The three proteins show competitive binding to Nck5a suggesting that they bind at a common site. The binding site has been mapped to a region of 26 amino acid residues (residues 145 to 170) at the N-terminal boundary of the kinase activation domain of Nck5a. This region of Nck5a contains an amphipathic alpha-helix whose hydrophobic face is involved in Cdk5 activation (Chin, K. T., Ohki, S, Tang, D., Cheng, H. C., Wang, J. H. , and Zhang, M. (1999) J. Biol. Chem. 274, 7120-7127). Several lines of evidence suggest that Nck5a interacts with the binding proteins at the hydrophilic face of the amphipathic alpha-helix. First, the Nck5a-(145-170) peptide can bind Cdk5 and Nck5a-binding proteins simultaneously. Second, the association of Nck5a-(145-170) to C48 can be markedly reduced by high ionic strength whereas the interaction between Nck5a and Cdk5 is not affected. Third, substitution of Glu(157) by glutamine in Nck5a-(145-170) abolishes the peptide's ability to bind to the three Nck5a-binding proteins without diminishing its Cdk5 binding activity.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Substitution / genetics
  • Binding, Competitive
  • Carrier Proteins / metabolism*
  • Cell Cycle Proteins
  • Cyclin-Dependent Kinase 5
  • Cyclin-Dependent Kinases / metabolism
  • Enzyme Activation
  • Humans
  • Intracellular Signaling Peptides and Proteins*
  • Macromolecular Substances
  • Mutation / genetics
  • Nerve Tissue Proteins / chemistry*
  • Nerve Tissue Proteins / genetics
  • Nerve Tissue Proteins / metabolism*
  • Osmolar Concentration
  • Peptide Fragments / metabolism
  • Protein Binding
  • Protein Structure, Secondary
  • Protein Structure, Tertiary
  • Recombinant Fusion Proteins / metabolism
  • Tumor Suppressor Proteins


  • CDK5RAP2 protein, human
  • CDK5RAP3 protein, human
  • Carrier Proteins
  • Cell Cycle Proteins
  • Intracellular Signaling Peptides and Proteins
  • Macromolecular Substances
  • Nerve Tissue Proteins
  • Peptide Fragments
  • Recombinant Fusion Proteins
  • Tumor Suppressor Proteins
  • neuronal Cdk5 activator (p25-p35)
  • Cyclin-Dependent Kinase 5
  • CDK5 protein, human
  • Cyclin-Dependent Kinases
  • CDK5RAP1 protein, human