PPP2R2B Gene

PPP2R2B (Protein Phosphatase 2 Regulatory Subunit B Beta)

Introduction

Ppp2R2B Gene is an important component in the neurobiology of neurodegenerative diseases. This page provides detailed information about its structure, function, and role in disease processes.

Overview

PPP2R2B (Protein Phosphatase 2 Regulatory Subunit B Beta)

Introduction

Ppp2R2B Gene is an important component in the neurobiology of neurodegenerative diseases. This page provides detailed information about its structure, function, and role in disease processes.

Overview

<div class="infobox infobox-gene"> [@oleary2020]
<table> [@liu2019]
<tr><th>Gene Symbol</th><td>PPP2R2B</td></tr> [@vafai2022]
<tr><th>Full Name</th><td>Protein Phosphatase 2 Regulatory Subunit B Beta</td></tr>
<tr><th>Chromosomal Location</th><td>5q31.3</td></tr>
<tr><th>NCBI Gene ID</th><td>[5520](https://www.ncbi.nlm.nih.gov/gene/5520)</td></tr>
<tr><th>OMIM</th><td>[604326](https://www.omim.org/entry/604326)</td></tr>
<tr><th>Ensembl ID</th><td>ENSG00000156475</td></tr>
<tr><th>UniProt ID</th><td>[Q9Y2T7](https://www.uniprot.org/uniprot/Q9Y2T7)</td></tr>
<tr><th>Associated Diseases</th><td>Spinocerebellar Ataxia Type 12 (SCA12)</td></tr>
</table>
</div>

Function

PPP2R2B encodes the β isoform of the B55 regulatory subunit of protein phosphatase 2A (PP2A). This regulatory subunit targets [PP2A](/entities/pp2a) to specific substrates, modulating phosphorylation states of key neuronal proteins.

Structure and Function

• Protein Family: PP2A B subunit family (B55/B/PR55)
• Function: Regulatory subunit targeting PP2A to specific substrates
• Expression: Neuronal tissue, particularly cerebellum and cerebral [cortex](/brain-regions/cortex)
• PP2A complex: Forms heterotrimeric complex with catalytic (C) and scaffolding (A) subunits

Physiological Role

PPP2R2B-containing PP2A complexes:

• Dephosphorylates [tau](/proteins/tau): Regulates [tau](/proteins/tau) phosphorylation at multiple sites
• Modulates neurotransmission: Targets synaptic proteins
• Cell cycle regulation: Neuronal cell cycle control
• [Apoptosis](/mechanisms/apoptosis) regulation: Pro-/anti-apoptotic signaling

Disease Associations

Spinocerebellar Ataxia Type 12 (SCA12)

SCA12 is caused by a CAG repeat expansion in the 5'UTR of PPP2R2B:

• Repeat length: Normal < 40, pathogenic > 51
• Inheritance: Autosomal dominant
• Onset: Typically in the 4th-5th decade

• Cerebellar ataxia (gait, limb, speech)
• Movement disorders (tremor, parkinsonism)
• Psychiatric symptoms (depression, anxiety)
• Cognitive impairment in later stages
• Cortical thumb sign on MRI

• CAG expansion reduces PPP2R2B expression
• Altered PP2A activity in [neurons](/entities/neurons)
• Deregulated phosphorylation of neuronal substrates
• Progressive cerebellar degeneration

Expression

PPP2R2B shows regional expression:

• Cerebral cortex (highest)
• Cerebellar Purkinje cells
• Basal ganglia
• [Hippocampus](/brain-regions/hippocampus)
• Spinal cord motor neurons

Therapeutic Targeting

Current therapeutic approaches:

• PP2A modulators: Drugs that restore PP2A activity
• Antisense oligonucleotides: Targeting expanded repeat transcripts
• Symptomatic treatment: Tremor control, psychiatric management
• Physical therapy: Balance and gait training

Key Publications

Background

The study of Ppp2R2B Gene has evolved significantly over the past decades. Research in this area has revealed important insights into the underlying mechanisms of neurodegeneration and continues to drive therapeutic development.

Historical context and key discoveries in this field have shaped our current understanding and will continue to guide future research directions.

See Also

• [Spinocerebellar Ataxia](/diseases/spinocerebellar-ataxia) Disease Index
• Cerebellar Degeneration - Mechanism
• [Tau Pathology](/mechanisms/tauopathies) - Related Pathway
• PP2A Signaling - Related Biology

External Links

• [NCBI Gene: PPP2R2B](https://www.ncbi.nlm.nih.gov/gene/5520)
• [UniProt: Q9Y2T7](https://www.uniprot.org/uniprot/Q9Y2T7)
• [OMIM: 604326](https://www.omim.org/entry/604326)
• [GeneReviews: SCA12](https://www.ncbi.nlm.nih.gov/books/NBK1144/)

Therapeutic Implications

PP2A-B55β is a promising target for neurodegenerative disease therapy. Inhibitors that activate PP2A are being developed for AD and PD, while inhibitors are being investigated for certain cancers. The challenge is achieving tissue-specific modulation.

| Approach | Target | Stage | Indication |
|----------|--------|-------|------------|
| LB-100 | PP2A activator | Clinical | Solid tumors, AD |
| Small molecule activators | PP2A-B55β | Preclinical | PD |
| PP2A-B55β inhibitors | PP2A-B55β | Discovery | Cancer |

Research Directions

Current research focuses on understanding how PP2A-B55β dysregulation contributes to tau hyperphosphorylation in AD. Studies are investigating the role of PP2A-B55β in α-synuclein phosphorylation in PD. Additionally, research is exploring biomarkers for PP2A activity in cerebrospinal fluid.

Brain Atlas Resources

• [Allen Human Brain Atlas - PPP2R2B Expression](https://human.brain-map.org/microarray/search/show?search_term=PPP2R2B)
• [Allen Cell Type Atlas - PPP2R2B](https://celltypes.brain-map.org/)
• [BrainSpan - PPP2R2B Developmental Expression](https://brainspan.org/)
• [Allen Mouse Brain Atlas - PPP2R2B](https://mouse.brain-map.org/)

References

Pathway Diagram

The following diagram shows the key molecular relationships involving PPP2R2B Gene discovered through SciDEX knowledge graph analysis: