Defining the Protein Phosphatase 2A (PP2A) Subcomplexes That Regulate FoxO Transcription Factor Localization

The family of forkhead box O (FoxO) transcription factors regulate cellular processes involved in glucose metabolism, stress resistance, DNA damage repair, and tumor suppression. FoxO transactivation activity is tightly regulated by a complex network of signaling pathways and post-translational modi...

Full description

Saved in:
Bibliographic Details
Main Authors: Adeline M. Luperchio, Daniel J. Salamango
Format: Article
Language:English
Published: MDPI AG 2025-02-01
Series:Cells
Subjects:
Online Access:https://www.mdpi.com/2073-4409/14/5/342
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1850050867226476544
author Adeline M. Luperchio
Daniel J. Salamango
author_facet Adeline M. Luperchio
Daniel J. Salamango
author_sort Adeline M. Luperchio
collection DOAJ
description The family of forkhead box O (FoxO) transcription factors regulate cellular processes involved in glucose metabolism, stress resistance, DNA damage repair, and tumor suppression. FoxO transactivation activity is tightly regulated by a complex network of signaling pathways and post-translational modifications. While it has been well established that phosphorylation promotes FoxO cytoplasmic retention and inactivation, the mechanism underlying dephosphorylation and nuclear translocation is less clear. Here, we investigate the role of protein phosphatase 2A (PP2A) in regulating this process. We demonstrate that PP2A and AMP-activated protein kinase (AMPK) combine to regulate nuclear translocation of multiple FoxO family members following inhibition of metabolic signaling or induction of oxidative stress. Moreover, chemical inhibitor studies indicate that nuclear accumulation of FoxO proteins occurs through inhibition of nuclear export as opposed to promoting nuclear import as previously speculated. Functional, genetic, and biochemical studies combine to identify the PP2A complexes that regulate FoxO nuclear translocation, and the binding motif required. Mutating the FoxO-PP2A interface to enhance or diminish PP2A binding alters nuclear translocation kinetics accordingly. Together, these studies shed light on the molecular mechanisms regulating FoxO nuclear translocation and provide insights into how FoxO regulation is integrated with metabolic and stress-related stimuli.
format Article
id doaj-art-00475e9876b44ba1b64fc7daba45462a
institution DOAJ
issn 2073-4409
language English
publishDate 2025-02-01
publisher MDPI AG
record_format Article
series Cells
spelling doaj-art-00475e9876b44ba1b64fc7daba45462a2025-08-20T02:53:19ZengMDPI AGCells2073-44092025-02-0114534210.3390/cells14050342Defining the Protein Phosphatase 2A (PP2A) Subcomplexes That Regulate FoxO Transcription Factor LocalizationAdeline M. Luperchio0Daniel J. Salamango1Department of Microbiology, Immunology, and Molecular Genetics, UT Health Science Center, San Antonio, TX 78229, USADepartment of Microbiology, Immunology, and Molecular Genetics, UT Health Science Center, San Antonio, TX 78229, USAThe family of forkhead box O (FoxO) transcription factors regulate cellular processes involved in glucose metabolism, stress resistance, DNA damage repair, and tumor suppression. FoxO transactivation activity is tightly regulated by a complex network of signaling pathways and post-translational modifications. While it has been well established that phosphorylation promotes FoxO cytoplasmic retention and inactivation, the mechanism underlying dephosphorylation and nuclear translocation is less clear. Here, we investigate the role of protein phosphatase 2A (PP2A) in regulating this process. We demonstrate that PP2A and AMP-activated protein kinase (AMPK) combine to regulate nuclear translocation of multiple FoxO family members following inhibition of metabolic signaling or induction of oxidative stress. Moreover, chemical inhibitor studies indicate that nuclear accumulation of FoxO proteins occurs through inhibition of nuclear export as opposed to promoting nuclear import as previously speculated. Functional, genetic, and biochemical studies combine to identify the PP2A complexes that regulate FoxO nuclear translocation, and the binding motif required. Mutating the FoxO-PP2A interface to enhance or diminish PP2A binding alters nuclear translocation kinetics accordingly. Together, these studies shed light on the molecular mechanisms regulating FoxO nuclear translocation and provide insights into how FoxO regulation is integrated with metabolic and stress-related stimuli.https://www.mdpi.com/2073-4409/14/5/342AKTFoxOPI3KPP2Asubcellular localizationtranscription factor
spellingShingle Adeline M. Luperchio
Daniel J. Salamango
Defining the Protein Phosphatase 2A (PP2A) Subcomplexes That Regulate FoxO Transcription Factor Localization
Cells
AKT
FoxO
PI3K
PP2A
subcellular localization
transcription factor
title Defining the Protein Phosphatase 2A (PP2A) Subcomplexes That Regulate FoxO Transcription Factor Localization
title_full Defining the Protein Phosphatase 2A (PP2A) Subcomplexes That Regulate FoxO Transcription Factor Localization
title_fullStr Defining the Protein Phosphatase 2A (PP2A) Subcomplexes That Regulate FoxO Transcription Factor Localization
title_full_unstemmed Defining the Protein Phosphatase 2A (PP2A) Subcomplexes That Regulate FoxO Transcription Factor Localization
title_short Defining the Protein Phosphatase 2A (PP2A) Subcomplexes That Regulate FoxO Transcription Factor Localization
title_sort defining the protein phosphatase 2a pp2a subcomplexes that regulate foxo transcription factor localization
topic AKT
FoxO
PI3K
PP2A
subcellular localization
transcription factor
url https://www.mdpi.com/2073-4409/14/5/342
work_keys_str_mv AT adelinemluperchio definingtheproteinphosphatase2app2asubcomplexesthatregulatefoxotranscriptionfactorlocalization
AT danieljsalamango definingtheproteinphosphatase2app2asubcomplexesthatregulatefoxotranscriptionfactorlocalization