PPP2R2B Gene - Protein Phosphatase 2 Regulatory Subunit B Beta
A key regulator of PP2A holoenzyme specificity and substrate dephosphorylation, implicated in spinocerebellar ataxia and cancer.
Gene Information Card
| Symbol | PPP2R2B |
|---|---|
| Full Name | Protein Phosphatase 2 Regulatory Subunit B, Beta |
| Gene Type | Protein coding |
| Chromosomal Location | 5q32 |
| NCBI Gene ID | 5521 ncbi.nlm.nih.gov/gene/5521 |
| Ensembl ID | ENSG00000145777 |
| UniProt ID | Q00005 |
| OMIM ID | 604325 |
| HGNC ID | 9305 |
| Aliases | B55beta, PP2A-B55beta, PR2AB55B, PR55BETA |
Description
PPP2R2B encodes the beta isoform of the B55 regulatory subunit of protein phosphatase 2A (PP2A). This subunit determines substrate specificity and subcellular localization of the PP2A holoenzyme, which dephosphorylates serine/threonine residues. The gene contains a CAG repeat in the 5' UTR; expansion of this repeat causes spinocerebellar ataxia type 12 (SCA12). PPP2R2B also functions as a tumor suppressor by regulating cell cycle and apoptosis.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Spinocerebellar ataxia type 12 (SCA12) | Expansion of a CAG trinucleotide repeat in the 5' UTR leads to altered PPP2R2B expression and PP2A activity, causing neurodegeneration. | OMIM #604326; ClinVar |
| Breast cancer | Reduced expression or loss of PPP2R2B impairs PP2A-mediated dephosphorylation of oncogenic substrates (e.g., AKT, ERK), promoting proliferation. | COSMIC; PMID: 22926525 |
| Lung cancer | Somatic mutations and promoter hypermethylation of PPP2R2B contribute to PP2A inactivation and tumor progression. | COSMIC; PMID: 23542345 |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Brain | 12.5 | High |
| Heart | 8.3 | Medium |
| Liver | 4.1 | Low |
| Kidney | 6.7 | Medium |
| Testis | 9.2 | Medium |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HEK293 | 15.2 | High expression |
| HeLa | 10.8 | Medium expression |
| MCF7 | 7.5 | Medium expression |
| A549 | 5.3 | Low expression |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| CAG repeat expansion (5' UTR) | Repeat expansion | Variable (normal 4-31; pathogenic >51) | Altered PPP2R2B expression; SCA12 |
| p.Arg183Trp | Missense | <0.01% | Unknown functional effect |
| c.1-?_*_del | Deletion | Rare | Loss of function; cancer |
Mutation functional classification
Loss of Function (LOF)
Deletions and promoter hypermethylation reduce PPP2R2B expression, impairing PP2A tumor suppressor activity.
Gain of Function (GOF)
Not reported.
Dominant Negative (DN)
CAG repeat expansion may produce a toxic RNA or protein with dominant-negative effects on PP2A function.
View complete mutation data：
Gene Ontology (GO)
Pathways
• PP2A-mediated dephosphorylation (Reactome: R-HSA-163285)
• Signaling by Receptor Tyrosine Kinases (Reactome: R-HSA-9006925)
• Cell Cycle
• Mitotic (Reactome: R-HSA-69278)
Protein Summary
PPP2R2B encodes the B55beta regulatory subunit of protein phosphatase 2A (PP2A). This subunit directs PP2A to specific substrates such as AKT, ERK, and p53, controlling cell cycle progression, apoptosis, and neuronal survival. The protein is highly expressed in brain and testis. Mutations and CAG repeat expansions in PPP2R2B are linked to spinocerebellar ataxia type 12 and various cancers.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| PPP2R2B Knockout HEK293 Cell Line | EDJ-KQ852 | Human | 5521 | Details Get a Quote |
| PPP2R2B Knockout HeLa Cell Line | EDJ-KQ18364 | Human | 5521 | Details Get a Quote |
| PPP2R2B Knockout A-549 Cell Line | EDJ-KQ62690 | Human | 5521 | Details Get a Quote |
| PPP2R2B Knockout HCT 116 Cell Line | EDJ-KQ71159 | Human | 5521 | Details Get a Quote |
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