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Identification of Intracellular Signaling Events Induced in Viable Cells by Interaction with Neighboring Cells Undergoing Apoptotic Cell Death
09:18

Identification of Intracellular Signaling Events Induced in Viable Cells by Interaction with Neighboring Cells Undergoing Apoptotic Cell Death

Published on: December 27, 2016

G1 to S phase transition protein 1 induces apoptosis signal-regulating kinase 1 activation by dissociating 14-3-3

J A Lee1, J E Park, D H Lee

  • 1College of Pharmacy, Chung-Ang University, Seoul, Republic of Korea.

Oncogene
|August 19, 2007
PubMed

Insights

G(1) to S phase transition protein 1 (GSPT1) regulates apoptosis signal-regulating kinase 1 (ASK1) by enhancing its activity. GSPT1 promotes ASK1-induced apoptosis by increasing ASK1 autophosphorylation and inhibiting its interaction with 14-3-3 protein.

Area of Science:

  • Cellular Biology
  • Molecular Biology
  • Biochemistry

Background:

  • Apoptosis signal-regulating kinase 1 (ASK1) is a key mediator of apoptosis, crucial for cellular responses to various death stimuli.
  • ASK1 activity is tightly regulated through mechanisms like post-translational modifications and protein-protein interactions.

Purpose of the Study:

  • To identify novel regulators of ASK1 activity and its role in apoptosis.
  • To elucidate the mechanism by which G(1) to S phase transition protein 1 (GSPT1) influences ASK1-mediated apoptosis.

Main Methods:

  • In vitro kinase assays to assess ASK1 autophosphorylation and kinase activity.
  • Co-immunoprecipitation to study protein-protein interactions between GSPT1 and ASK1.
  • Small interfering RNA (siRNA) analysis to evaluate the effect of GSPT1 expression levels on ASK1 activity.
  • Caspase-3 activity assays to measure apoptosis induction.

Main Results:

  • GSPT1 interacts with ASK1 and enhances ASK1-induced apoptosis via caspase-3 activation.
  • GSPT1 promotes ASK1 autophosphorylation and increases its kinase activity.
  • ASK1 autophosphorylation is dependent on endogenous GSPT1 levels.
  • GSPT1 inhibits the interaction between ASK1 and the inhibitory protein 14-3-3, but not the activating protein TRAF2.

Conclusions:

  • GSPT1 acts as a novel positive regulator of ASK1-mediated apoptosis.
  • GSPT1 enhances ASK1 activity by promoting autophosphorylation and disrupting the inhibitory ASK1-14-3-3 interaction.
  • These findings reveal a new regulatory pathway in apoptosis signaling involving GSPT1 and ASK1.

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