The luciferase-based in vivo protein-protein interaction assay revealed that CHK1 promotes PP2A and PME-1 interaction

Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved..

Protein phosphatase 2A (PP2A) is an essential serine/threonine protein phosphatase, and its dysfunction is involved in the onset of cancer and neurodegenerative disorders. PP2A functions as a trimeric holoenzyme whose composition is regulated by the methyl-esterification (methylation) of the PP2A catalytic subunit (PP2Ac). Protein phosphatase methylesterase-1 (PME-1) is the sole PP2Ac methylesterase, and the higher PME-1 expression is observed in various cancer and neurodegenerative diseases. Apart from serving as a methylesterase, PME-1 acts as a PP2A inhibitory protein, binding directly to PP2Ac and suppressing its activity. The intricate function of PME-1 hinders drug development by targeting the PME-1/PP2Ac axis. This study applied the NanoBiT system, a bioluminescence-based protein interaction assay, to elucidate the molecular mechanism that modulates unknown PME-1/PP2Ac protein-protein interaction (PPI). Compound screening identified that the CHK1 inhibitors inhibited PME-1/PP2Ac association without affecting PP2Ac methylation levels. CHK1 directly phosphorylates PP2Ac to promote PME-1 association. Phospho-mass spectrometry identified multiple phospho-sites on PP2Ac, including the Thr219, that affect PME-1 interaction. An anti-phospho-Thr219 PP2Ac antibody was generated and showed that CHK1 regulates the phosphorylation levels of this site in cells. On the contrary, in vitro phosphatase assay showed that CHK1 is the substrate of PP2A, and PME-1 hindered PP2A-mediated dephosphorylation of CHK1. Our data provides novel insights into the molecular mechanisms governing the PME-1/PP2Ac PPI and the triad relationship between PP2A, PME-1, and CHK1.

Medienart:

E-Artikel

Erscheinungsjahr:

2024

Erschienen:

2024

Enthalten in:

Zur Gesamtaufnahme - year:2024

Enthalten in:

The Journal of biological chemistry - (2024) vom: 06. Apr., Seite 107277

Sprache:

Englisch

Beteiligte Personen:

Ando, Sana [VerfasserIn]
Tanaka, Keiko [VerfasserIn]
Matsumoto, Maharu [VerfasserIn]
Oyama, Yuki [VerfasserIn]
Tomabechi, Yuri [VerfasserIn]
Yamagata, Atsushi [VerfasserIn]
Shirouzu, Mikako [VerfasserIn]
Nakagawa, Reiko [VerfasserIn]
Okimoto, Noriaki [VerfasserIn]
Taiji, Makoto [VerfasserIn]
Sato, Koichi [VerfasserIn]
Ohama, Takashi [VerfasserIn]

Links:

Volltext

Themen:

CHK1
DNA damage
Journal Article
NanoBiT system
PME-1
PP2A

Anmerkungen:

Date Revised 08.04.2024

published: Print-Electronic

Citation Status Publisher

doi:

10.1016/j.jbc.2024.107277

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM370781562