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Development of Inhibitors of Protein-protein Interactions through REPLACE: Application to the Design and Development Non-ATP Competitive CDK Inhibitors
10:33

Development of Inhibitors of Protein-protein Interactions through REPLACE: Application to the Design and Development Non-ATP Competitive CDK Inhibitors

Published on: October 26, 2015

p13suc1 suppresses the catalytic function of p34cdc2 kinase for intermediate filament proteins, in vitro

M Kusubata1, T Tokui, Y Matsuoka

  • 1Department of Neurophysiology, Tokyo Metropolitan Institute of Gerontology, Japan.

The Journal of Biological Chemistry
|October 15, 1992
PubMed

Insights

The p13suc1 protein selectively inhibits the p34cdc2 kinase, preventing the phosphorylation and disassembly of specific filament proteins like vimentin and desmin. This finding clarifies the role of p13suc1 in cell cycle regulation.

Area of Science:

  • Cell Biology
  • Molecular Biology
  • Biochemistry

Background:

  • p34cdc2 kinase activity regulates cell cycle progression through mitosis.
  • The precise role of p13suc1 in modulating p34cdc2 kinase function remains incompletely understood despite known interactions.

Purpose of the Study:

  • To investigate the specific effects of p13suc1 on p34cdc2 kinase activity.
  • To characterize the phosphorylation of filament proteins by purified p34cdc2 kinase.

Main Methods:

  • Developed a novel purification method for p34cdc2 kinase, free from p13suc1 association, using a buffer with 0.5 M NaCl and 50% ethylene glycol.
  • Assessed the stoichiometric phosphorylation of vimentin and desmin by purified p34cdc2 kinase.
  • Utilized peptide mapping to analyze the site-specificity of p13suc1 inhibition.

Main Results:

  • Purified p34cdc2 kinase efficiently phosphorylated vimentin and desmin.
  • Exogenous p13suc1 significantly suppressed the phosphorylation of vimentin and desmin, inhibiting filament disassembly.
  • Histone H1 phosphorylation remained unaffected by p13suc1, indicating selective inhibition.
  • Peptide mapping revealed non-site-specific inhibition of vimentin and desmin phosphorylation by p13suc1.

Conclusions:

  • p13suc1 exhibits a selective inhibitory effect on the catalytic activity of p34cdc2 kinase towards specific filament proteins.
  • This selectivity suggests a crucial regulatory role for p13suc1 in controlling cytoskeletal dynamics during mitosis.

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