PPP2R1B: Protein Phosphatase 2 Regulatory Subunit B Beta
A key regulator of cell signaling and tumor suppression
Gene Information Card
| Symbol | PPP2R1B |
|---|---|
| Full Name | Protein Phosphatase 2 Regulatory Subunit B Beta |
| Gene Type | Protein coding |
| Chromosomal Location | 11q23.1 |
| NCBI Gene ID | 5519 ncbi.nlm.nih.gov/gene/5519 |
| Ensembl ID | ENSG00000137713 |
| UniProt ID | P30154 |
| OMIM ID | 603113 |
| HGNC ID | 9303 |
| Aliases | PR65B, PP2A-Abeta, PP2A PR65-B |
Description
PPP2R1B encodes the beta isoform of the A subunit (PR65) of protein phosphatase 2 (PP2A), a major serine/threonine phosphatase involved in cell cycle regulation, growth signaling, and apoptosis. The A subunit serves as a scaffold for the catalytic C subunit and regulatory B subunits. Mutations and altered expression of PPP2R1B are implicated in various cancers, including lung, breast, and colorectal carcinomas.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Lung cancer | Loss of heterozygosity and somatic mutations in PPP2R1B disrupt PP2A holoenzyme assembly, impairing tumor suppressor function. | PMID: 9660920 |
| Colorectal cancer | Mutations in PPP2R1B reduce PP2A activity, promoting Wnt/β-catenin signaling. | PMID: 15355999 |
| Breast cancer | Decreased PPP2R1B expression correlates with poor prognosis and altered AKT signaling. | PMID: 21947055 |
| Hepatocellular carcinoma | PPP2R1B mutations found in a subset of tumors, suggesting a role in liver carcinogenesis. | PMID: 12007222 |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Brain | 12.5 | Medium |
| Heart | 8.3 | Medium |
| Liver | 6.1 | Low |
| Lung | 7.8 | Medium |
| Kidney | 9.2 | Medium |
| Testis | 15.0 | High |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HeLa | 10.2 | Cervical cancer cell line |
| A549 | 8.5 | Lung cancer cell line |
| MCF7 | 7.9 | Breast cancer cell line |
| HEK293 | 11.0 | Embryonic kidney cell line |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.539G>A (p.Arg180Gln) | Missense | <1% | Impaired binding to regulatory B subunits |
| c.1123C>T (p.Arg375Trp) | Missense | <1% | Reduced PP2A activity |
| c.1465_1466del (p.Leu489fs) | Frameshift | <0.5% | Loss of function |
| c.1A>G (p.Met1Val) | Start loss | <0.1% | Complete loss of protein expression |
Mutation functional classification
Loss of Function (LOF)
Most reported mutations in PPP2R1B result in loss of scaffold function, reducing PP2A holoenzyme assembly and activity.
Gain of Function (GOF)
No evidence of gain-of-function mutations in PPP2R1B.
Dominant Negative (DN)
Some missense mutations (e.g., p.Arg180Gln) may act in a dominant-negative manner by sequestering catalytic or regulatory subunits.
View complete mutation data：
Gene Ontology (GO)
| • GO:0000159 - protein phosphatase type 2A complex | • GO:0005515 - protein binding |
| • GO:0006470 - protein dephosphorylation | • GO:0007165 - signal transduction |
| • GO:0008283 - cell population proliferation | • GO:0043085 - positive regulation of catalytic activity |
Pathways
• hsa04110 - Cell cycle
• hsa04115 - p53 signaling pathway
• hsa04310 - Wnt signaling pathway
• hsa04010 - MAPK signaling pathway
• hsa04151 - PI3K-Akt signaling pathway
Protein Summary
The PPP2R1B protein (PR65 beta) is a 589-amino acid scaffold subunit of PP2A. It contains 15 HEAT repeats that mediate interactions with the catalytic C subunit and various regulatory B subunits. PR65 beta is essential for PP2A holoenzyme stability and substrate specificity. The protein is ubiquitously expressed, with highest levels in testis and brain. Structural alterations due to mutations can disrupt PP2A function, contributing to oncogenic signaling.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| PPP2R1B Knockout HEK293 Cell Line | EDJ-KQ395 | Human | 5519 | Details Get a Quote |
| PPP2R1B Knockout A-549 Cell Line | EDJ-KQ18618 | Human | 5519 | Details Get a Quote |
| PPP2R1B Knockout HCT 116 Cell Line | EDJ-KQ18619 | Human | 5519 | Details Get a Quote |
| PPP2R1B Knockout HeLa Cell Line | EDJ-KQ18620 | Human | 5519 | Details Get a Quote |
| Ppp2r1b Knockout 3T3-Swiss albino Cell Line | EDJ-KZ410 | Mouse | 5519 | Details Get a Quote |
| PPP2R1B Knockout HAP1 Cell Line | EDC07950 | Human | 5519 | Details Get a Quote |
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