Seroatlas · Human Serome Atlas

PTPA

Serine/threonine-protein phosphatase 2A activator

Also known as: PPP2R4, PR53, PTPA_HUMAN

Cross-references: UniProt · Ensembl · Human Protein Atlas · GeneCards · NCBI Gene

Protein identityUniProt · HPA

UniProt accession
Q15257
Gene
PTPA
Ensembl
ENSG00000119383
Chromosome
9
Canonical length
358 aa
Protein class
Enzymes, Plasma proteins, Predicted intracellular proteins
Subcellular location
Nucleoplasm,Cytosol

OverviewNCBI Gene

Protein phosphatase 2A is one of the four major Ser/Thr phosphatases and is implicated in the negative control of cell growth and division. Protein phosphatase 2A holoenzymes are heterotrimeric proteins composed of a structural subunit A, a catalytic subunit C, and a regulatory subunit B. The regulatory subunit is encoded by a diverse set of genes that have been grouped into the B/PR55, B'/PR61, and B''/PR72 families. These different regulatory subunits confer distinct enzymatic specificities and intracellular localizations to the holozenzyme. The product of this gene belongs to the B' family. This gene encodes a specific phosphotyrosyl phosphatase activator of the dimeric form of protein phosphatase 2A. Alternative splicing results in multiple transcript variants encoding different isoforms. [provided by RefSeq, Jul 2008]

Canonical amino-acid sequenceUniProt

358 residues, UniProt reviewed canonical sequence.

>Q15257|PTPA
     1  MAEGERQPPP DSSEEAPPAT QNFIIPKKEI HTVPDMGKWK RSQAYADYIG FILTLNEGVK
    61  GKKLTFEYRV SEMWNEVHEE KEQAAKQSVS CDECIPLPRA GHCAPSEAIE KLVALLNTLD
   121  RWIDETPPVD QPSRFGNKAY RTWYAKLDEE AENLVATVVP THLAAAVPEV AVYLKESVGN
   181  STRIDYGTGH EAAFAAFLCC LCKIGVLRVD DQIAIVFKVF NRYLEVMRKL QKTYRMEPAG
   241  SQGVWGLDDF QFLPFIWGSS QLIDHPYLEP RHFVDEKAVN ENHKDYMFLE CILFITEMKT
   301  GPFAEHSNQL WNISAVPSWS KVNQGLIRMY KAECLEKFPV IQHFKFGSLL PIHPVTSG

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against PTPA can act on the native protein depends on physical access: surface and secreted proteins are reachable by circulating antibodies, intracellular proteins usually are not.

Antibody reachability
Intracellular
Secreted
No
Transmembrane segments
0
Mean surface accessibility (rSASA)
0.29
Highest tissue expression
319 nTPM

Expression across tissuesHPA

Tissue

  • skeletal muscle: 319 nTPM
  • tongue: 192 nTPM
  • heart muscle: 167 nTPM
  • cerebral cortex: 158 nTPM
  • liver: 150 nTPM
  • parathyroid gland: 138 nTPM

Single-cell type

  • loop of henle epithelial cells: 29 nCPM
  • distal convoluted tubule cells: 27 nCPM
  • papillary tip epithelial cells: 26 nCPM
  • renal collecting duct principal cells: 26 nCPM
  • renal collecting duct intercalated cells: 24 nCPM
  • proximal tubule cells: 24 nCPM

Immune cell

  • myeloid DC: 23 nTPM
  • gdT-cell: 21 nTPM
  • NK-cell: 21 nTPM
  • total PBMC: 20 nTPM
  • MAIT T-cell: 20 nTPM
  • classical monocyte: 19 nTPM

Brain region

  • thalamus: 219 nTPM
  • cerebral cortex: 217 nTPM
  • amygdala: 203 nTPM
  • medulla oblongata: 189 nTPM
  • hippocampal formation: 189 nTPM
  • midbrain: 186 nTPM

DiseaseUniProt · ClinVar · IEDB · PubMed

Four sources answering four different questions about PTPA.

Disease | AllUniProt

Conditions PTPA is implicated in, by any mechanism.

  • Parkinson disease 25, autosomal recessive early-onset, with impaired intellectual development (PARK25) MIM:620482

Disease | GeneticClinVar

2 pathogenic / likely-pathogenic of 31 ClinVar records.

Conditions with pathogenic or likely-pathogenic variants.

  • Parkinson disease 25, autosomal recessive early-onset, with impaired intellectual development

Genetic constraint and essentialitygnomAD · DepMap

Does the body need this protein intact? Low LOEUF or a strong DepMap dependency means loss or blockade of the protein is likely to be felt.

gnomAD LOEUF (loss-of-function intolerance)
0.26
gnomAD pLI
0.99
DepMap mean gene effect
-0.56
DepMap dependency class
common

Cancer expressionTCGA

Across TCGA tumor cohorts, this protein is over-expressed in roughly 5% of surveyed tumor types (aggregate summary; per-cohort expression, alteration, and survival load in the interactive view).

OntologyGO

Biological processes

Molecular functions

Cellular components

Protein domainsUniProt · Pfam · InterPro

  • Phosphotyrosyl phosphatase activator, PTPA
  • PTPA superfamily
  • Phosphotyrosyl phosphatase activator, C-terminal lid domain
  • Phosphotyrosyl phosphate activator (PTPA) protein

KeywordsUniProt

InteractionsUniProt · HPA

Protein binding partners of PTPA in the human serome: UniProt-annotated complex subunits plus reported interactors. Each links to its own Seroatlas record.

Antibody and autoantibody relevanceSeroatlas analysis

Seroatlas reads PTPA as an antibody target. Whether an autoantibody or antibody against PTPA could matter depends on whether native PTPA is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

PTPA is annotated as predominantly intracellular. Intracellular proteins are common autoantibody markers, becoming visible to the immune system after cell injury or altered processing, but are usually markers of disease rather than direct drivers.

Annotation status

The present source text does not explicitly label PTPA as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Canonical record: https://seroatlas.com/gene/PTPA. Study-independent annotations aggregated from UniProt, Human Protein Atlas, PubMed, IEDB, Pfam, InterPro, Gene Ontology, AlphaFold, gnomAD, DepMap, ClinVar, TCGA. Catalog release seroatlas-reviewed-human-uniprot-20260313.

Seroatlas is the reference for exploring autoantibody and antibody serology at the human-protein level: the autoreactome and human serome, multiplex serology (HuProt, HuScan, VirScan, PhIP-Seq).

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