Seroatlas · Human Serome Atlas

PPA2

Inorganic pyrophosphatase 2, mitochondrial

Also known as: FLJ20459, IPYR2_HUMAN

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

Protein identityUniProt · HPA

UniProt accession: Q9H2U2
Gene: PPA2
Ensembl: ENSG00000138777
Chromosome: 4
Canonical length: 334 aa
Protein class: Cancer-related genes, Disease related genes, Enzymes, Metabolic proteins, Plasma proteins, Potential drug targets, Predicted intracellular proteins
Subcellular location: Mitochondria
Quaternary structure: Homodimer

OverviewNCBI Gene

The protein encoded by this gene is localized to the mitochondrion, is highly similar to members of the inorganic pyrophosphatase (PPase) family, and contains the signature sequence essential for the catalytic activity of PPase. PPases catalyze the hydrolysis of pyrophosphate to inorganic phosphate, which is important for the phosphate metabolism of cells. Alternate transcriptional splice variants, encoding different isoforms, have been characterized. [provided by RefSeq, Jul 2008]

Canonical amino-acid sequenceUniProt

334 residues, UniProt reviewed canonical sequence.

>Q9H2U2|PPA2
     1  MSALLRLLRT GAPAAACLRL GTSAGTGSRR AMALYHTEER GQPCSQNYRL FFKNVTGHYI
    61  SPFHDIPLKV NSKEENGIPM KKARNDEYEN LFNMIVEIPR WTNAKMEIAT KEPMNPIKQY
   121  VKDGKLRYVA NIFPYKGYIW NYGTLPQTWE DPHEKDKSTN CFGDNDPIDV CEIGSKILSC
   181  GEVIHVKILG ILALIDEGET DWKLIAINAN DPEASKFHDI DDVKKFKPGY LEATLNWFRL
   241  YKVPDGKPEN QFAFNGEFKN KAFALEVIKS THQCWKALLM KKCNGGAINC TNVQISDSPF
   301  RCTQEEARSL VESVSSSPNK ESNEEEQVWH FLGK

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against PPA2 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): 0.31
Highest tissue expression: 33 nTPM

Expression across tissuesHPA

Tissue

tongue: 33 nTPM
choroid plexus: 28 nTPM
heart muscle: 27 nTPM
skeletal muscle: 26 nTPM
bone marrow: 20 nTPM
kidney: 19 nTPM

Single-cell type

esophageal suprabasal cells: 265 nCPM
lactotrophs: 265 nCPM
esophageal basal cells: 256 nCPM
gonadotrophs: 229 nCPM
oligodendrocyte progenitor cells: 221 nCPM
retinal pigment epithelial cells: 217 nCPM

Immune cell

myeloid DC: 50 nTPM
NK-cell: 36 nTPM
intermediate monocyte: 30 nTPM
memory B-cell: 29 nTPM
basophil: 27 nTPM
non-classical monocyte: 27 nTPM

Brain region

choroid plexus: 34 nTPM
hypothalamus: 28 nTPM
white matter: 27 nTPM
cerebral cortex: 27 nTPM
thalamus: 27 nTPM
midbrain: 24 nTPM

DiseaseUniProt · ClinVar · IEDB · PubMed

Four sources answering four different questions about PPA2.

Disease | AllUniProt

Conditions PPA2 is implicated in, by any mechanism.

Sudden cardiac failure, alcohol-induced (SCFAI) MIM:617223
Sudden cardiac failure, infantile (SCFI) MIM:617222

Disease | GeneticClinVar

18 pathogenic / likely-pathogenic of 432 ClinVar records.

Conditions with pathogenic or likely-pathogenic variants.

Sudden cardiac failure, infantile
Sudden cardiac failure, alcohol-induced
Inborn genetic diseases
Cardiovascular phenotype

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): 1.27
gnomAD pLI: 0
gnomAD missense Z: 0.43
DepMap mean gene effect: -0.38
DepMap dependency class: selective

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

Molecular functions

Cellular components

Protein domainsUniProt · Pfam · InterPro

KeywordsUniProt

Antibody and autoantibody relevanceSeroatlas analysis

Seroatlas reads PPA2 as an antibody target. Whether an autoantibody or antibody against PPA2 could matter depends on whether native PPA2 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

PPA2 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 PPA2 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

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