Seroatlas · Human Serome Atlas

PPA1

Inorganic pyrophosphatase

Also known as: IOPPP, IPYR_HUMAN, PP, PP1, Ppase, SID6-8061

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

Protein identityUniProt · HPA

UniProt accession: Q15181
Gene: PPA1
Ensembl: ENSG00000180817
Chromosome: 10
Canonical length: 289 aa
Protein class: Enzymes, Metabolic proteins, Predicted intracellular proteins
Subcellular location: Vesicles
Quaternary structure: Homodimer

OverviewNCBI Gene

The protein encoded by this gene is a member of the inorganic pyrophosphatase (PPase) family. PPases catalyze the hydrolysis of pyrophosphate to inorganic phosphate, which is important for the phosphate metabolism of cells. Studies of a similar protein in bovine suggested a cytoplasmic localization of this enzyme. [provided by RefSeq, Jul 2008]

Canonical amino-acid sequenceUniProt

289 residues, UniProt reviewed canonical sequence.

>Q15181|PPA1
     1  MSGFSTEERA APFSLEYRVF LKNEKGQYIS PFHDIPIYAD KDVFHMVVEV PRWSNAKMEI
    61  ATKDPLNPIK QDVKKGKLRY VANLFPYKGY IWNYGAIPQT WEDPGHNDKH TGCCGDNDPI
   121  DVCEIGSKVC ARGEIIGVKV LGILAMIDEG ETDWKVIAIN VDDPDAANYN DINDVKRLKP
   181  GYLEATVDWF RRYKVPDGKP ENEFAFNAEF KDKDFAIDII KSTHDHWKAL VTKKTNGKGI
   241  SCMNTTLSES PFKCDPDAAR AIVDALPPPC ESACTVPTDV DKWFHHQKN

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against PPA1 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): 0.24
Highest tissue expression: 308 nTPM

Expression across tissuesHPA

Tissue

retina: 308 nTPM
spinal cord: 228 nTPM
cerebellum: 194 nTPM
adrenal gland: 182 nTPM
pancreas: 178 nTPM
midbrain: 177 nTPM

Single-cell type

esophageal apical cells: 1,223 nCPM
müller glia: 951 nCPM
gastric progenitor cells: 931 nCPM
esophageal basal cells: 833 nCPM
esophageal suprabasal cells: 776 nCPM
endometrial luminal cells: 646 nCPM

Immune cell

myeloid DC: 190 nTPM
MAIT T-cell: 131 nTPM
naive CD4 T-cell: 123 nTPM
T-reg: 121 nTPM
memory CD4 T-cell: 113 nTPM
naive CD8 T-cell: 107 nTPM

Brain region

cerebellum: 167 nTPM
white matter: 163 nTPM
pons: 163 nTPM
spinal cord: 152 nTPM
medulla oblongata: 142 nTPM
hypothalamus: 129 nTPM

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): 1
gnomAD pLI: 0
gnomAD missense Z: 0.84
DepMap mean gene effect: -0.89
DepMap dependency class: common

Cancer expressionTCGA

Across TCGA tumor cohorts, this protein is over-expressed in roughly 4% of surveyed tumor types (aggregate summary; per-cohort expression, alteration, and survival load in the interactive view).

OntologyGO

Biological processes

phosphate-containing compound metabolic process

Molecular functions

Cellular components

Protein domainsUniProt · Pfam · InterPro

KeywordsUniProt

Antibody and autoantibody relevanceSeroatlas analysis

Seroatlas reads PPA1 as an antibody target. Whether an autoantibody or antibody against PPA1 could matter depends on whether native PPA1 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

PPA1 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 PPA1 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Loading the interactive Seroatlas protein explorer...