The tyrosine phosphatase CD148 interacts with the p85 regulatory subunit of phosphoinositide 3-kinase

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Co-immunoprecipitation Assay for Studying Functional Interactions Between Receptors and Enzymes
09:40

Co-immunoprecipitation Assay for Studying Functional Interactions Between Receptors and Enzymes

Published on: September 28, 2018

Nobuo Tsuboi1, Tadahiko Utsunomiya, Richard L Roberts

  • 1Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232, USA.

The Biochemical Journal
|March 20, 2008
PubMed

Insights

CD148 phosphatase dephosphorylates the p85 subunit of PI3K, modulating its activity. This interaction is crucial for regulating cell growth and transformation signaling pathways.

Area of Science:

  • Cell Biology
  • Molecular Biology
  • Biochemistry

Background:

  • CD148, a transmembrane tyrosine phosphatase, influences cell growth and transformation.
  • The precise signaling mechanisms of CD148 remain incompletely understood.

Purpose of the Study:

  • To identify intracellular molecules involved in CD148 signaling.
  • To elucidate the interaction between CD148 and phosphoinositide 3-kinase (PI3K).

Main Methods:

  • Modified yeast two-hybrid screening using a substrate-trapping mutant of CD148 (CD148 D/A).
  • In vitro and in intact cell assays to assess protein interactions and phosphorylation.
  • CD148 knock-down using siRNA.

Main Results:

  • CD148 D/A specifically interacted with the p85 regulatory subunit of PI3K in a phosphorylation-dependent manner.
  • CD148 dephosphorylated p85 in vitro and reduced p85 phosphorylation induced by active Src.
  • CD148 modulated PI3K activity, with knock-down increasing activity upon serum stimulation.

Conclusions:

  • CD148 interacts with and dephosphorylates the p85 subunit of PI3K.
  • This interaction modulates the magnitude of PI3K activity, impacting cell signaling pathways.

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