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Liprin alpha1 interacts with PP2A B56gamma

Jason D Arroyo1, Grace M Lee, William C Hahn

  • 1Department of Medical Oncology, Dana-Farber Cancer Institute, 44 Binney Street, Dana 1538, Boston, Massachusetts 02115, USA.

Cell Cycle (Georgetown, Tex.)
|February 1, 2008
PubMed

Insights

Protein phosphatase 2A (PP2A) B56gamma complexes interact with liprin alpha1, a novel binding partner. This interaction reveals a new role for PP2A B56gamma beyond its phosphatase activity, impacting cell morphology.

Area of Science:

  • Molecular Biology
  • Cell Biology
  • Biochemistry

Background:

  • Protein phosphatase 2A (PP2A) is a key serine-threonine phosphatase family involved in regulating numerous cellular processes.
  • Inhibition of PP2A contributes to human cell transformation, and specific subunits like B56gamma are crucial for its function.
  • Depletion of PP2A B56gamma complexes in immortalized human cells induces in vitro cell transformation.

Purpose of the Study:

  • To identify novel binding partners of the PP2A B56gamma regulatory subunit.
  • To investigate the functional significance of PP2A B56gamma interacting proteins.
  • To explore potential PP2A B56gamma functions independent of its phosphatase activity.

Main Methods:

  • Tandem affinity purification coupled with mass spectrometry was employed to identify proteins interacting with PP2A B56gamma.
  • RNA interference (RNAi) was used to suppress liprin alpha1 expression.
  • Cell morphology and transformation assays were performed.

Main Results:

  • Liprin alpha1 was identified as a novel protein interacting with PP2A B56gamma.
  • B56gamma-liprin alpha1 complexes were found to be distinct from PP2A complexes containing B56gamma.
  • While liprin alpha1 did not directly cause cell transformation, its suppression via RNAi led to altered cell morphology.

Conclusions:

  • PP2A B56gamma interacts with liprin alpha1, forming distinct complexes.
  • Liprin alpha1's role in altering cell morphology suggests a novel function for PP2A B56gamma independent of its phosphatase activity.
  • These findings open new avenues for understanding PP2A regulation and its role in cell biology.

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