PTPA: Protein Phosphatase 2 Phosphatase Activator
A key regulator of PP2A phosphatase activity, implicated in cancer and neurological disorders.
Gene Information Card
| Symbol | PTPA |
|---|---|
| Full Name | Protein Phosphatase 2 Phosphatase Activator |
| Gene Type | Protein coding |
| Chromosomal Location | 9q34.3 |
| NCBI Gene ID | 5524 ncbi.nlm.nih.gov/gene/5524 |
| Ensembl ID | ENSG00000136869 |
| UniProt ID | Q15257 |
| OMIM ID | 600756 |
| HGNC ID | 9308 |
| Aliases | PPP2R4, PP2A, PR53 |
Description
PTPA (Protein Phosphatase 2 Phosphatase Activator) encodes a regulatory subunit of protein phosphatase 2A (PP2A). The encoded protein activates the latent form of PP2A by converting the inactive dimeric form to the active heterotrimeric form. It also possesses peptidyl-prolyl cis-trans isomerase activity. PTPA is essential for PP2A holoenzyme assembly and function, impacting cell cycle regulation, signal transduction, and apoptosis.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Cancer (multiple types) | Dysregulation of PP2A activity via PTPA mutations or altered expression leads to aberrant cell proliferation and survival. | COSMIC; PMID: 23583978 |
| Neurodevelopmental disorders | Loss-of-function variants in PTPA impair PP2A activation, affecting neuronal signaling and development. | ClinVar; PMID: 31036916 |
| Alzheimer's disease | Reduced PTPA expression correlates with decreased PP2A activity and increased tau phosphorylation. | PMID: 21832049 |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Brain | 12.5 | Medium |
| Heart | 8.3 | Medium |
| Liver | 6.1 | Low |
| Kidney | 9.7 | Medium |
| Testis | 15.2 | High |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HEK293 | 14.8 | High expression |
| HeLa | 11.2 | Medium expression |
| K562 | 9.5 | Medium expression |
| MCF7 | 7.3 | Low expression |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.287G>A (p.Arg96His) | Missense | <0.1% | Reduced PP2A activation; associated with neurodevelopmental delay (ClinVar) |
| c.1A>G (p.Met1?) | Start loss | <0.1% | Loss of protein expression; likely pathogenic (ClinVar) |
| c.511C>T (p.Arg171Trp) | Missense | <0.1% | Impaired isomerase activity; reported in cancer (COSMIC) |
Mutation functional classification
Loss of Function (LOF)
Missense and truncating mutations that reduce or abolish PTPA's ability to activate PP2A, leading to decreased PP2A activity.
Gain of Function (GOF)
Not well documented; no clear gain-of-function mutations reported in major databases.
Dominant Negative (DN)
Some missense variants (e.g., p.Arg96His) may interfere with wild-type PTPA function in a dominant-negative manner, though evidence is limited.
View complete mutation data：
Gene Ontology (GO)
| • protein phosphatase type 2A regulator activity (GO:0008601) | • peptidyl-prolyl cis-trans isomerase activity (GO:0003755) |
| • protein kinase binding (GO:0019901) | • regulation of phosphoprotein phosphatase activity (GO:0043666) |
| • cytosol (GO:0005829) | • nucleus (GO:0005634) |
Pathways
• REACT: R-HSA-163615 - PP2A-mediated dephosphorylation
• REACT: R-HSA-69278 - Cell Cycle
• Mitotic
• REACT: R-HSA-1257604 - PIP3 activates AKT signaling
Protein Summary
PTPA (PPP2R4) is a 370-amino acid protein that functions as a specific activator of protein phosphatase 2A (PP2A). It binds to the PP2A dimer (catalytic and scaffold subunits) and induces a conformational change that allows the regulatory subunit to bind, forming the active trimeric holoenzyme. PTPA also exhibits peptidyl-prolyl cis-trans isomerase activity, which is required for its PP2A activation function. The protein is widely expressed, with highest levels in brain and testis. Mutations in PTPA are associated with neurodevelopmental disorders and cancer.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| PTPA Knockout HEK293 Cell Line | EDJ-KQ3709 | Human | 5524 | Details Get a Quote |
| PTPA Knockout A-549 Cell Line | EDJ-KQ24366 | Human | 5524 | Details Get a Quote |
| PTPA Knockout HCT 116 Cell Line | EDJ-KQ25738 | Human | 5524 | Details Get a Quote |
| PTPA Knockout HeLa Cell Line | EDJ-KQ25739 | Human | 5524 | Details Get a Quote |
Displaying Records 1 To 4 Of 4 Records
