Seroatlas · Human Serome Atlas

PPIG

Peptidyl-prolyl cis-trans isomerase G

Also known as: CARS-Cyp, PPIG_HUMAN, SCAF10, SRCyp

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

Protein identityUniProt · HPA

UniProt accession
Q13427
Gene
PPIG
Ensembl
ENSG00000138398
Chromosome
2
Canonical length
754 aa
Protein class
Enzymes, Metabolic proteins, Plasma proteins, Predicted intracellular proteins
Subcellular location
Nuclear speckles,Cytosol

OverviewNCBI Gene

Enables peptidyl-prolyl cis-trans isomerase activity. Predicted to be involved in protein folding. Located in cytosol and nuclear speck. [provided by Alliance of Genome Resources, Jul 2025]

Canonical amino-acid sequenceUniProt

754 residues, UniProt reviewed canonical sequence.

>Q13427|PPIG
     1  MGIKVQRPRC FFDIAINNQP AGRVVFELFS DVCPKTCENF RCLCTGEKGT GKSTQKPLHY
    61  KSCLFHRVVK DFMVQGGDFS EGNGRGGESI YGGFFEDESF AVKHNKEFLL SMANRGKDTN
   121  GSQFFITTKP TPHLDGHHVV FGQVISGQEV VREIENQKTD AASKPFAEVR ILSCGELIPK
   181  SKVKKEEKKR HKSSSSSSSS SSDSDSSSDS QSSSDSSDSE SATEEKSKKR KKKHRKNSRK
   241  HKKEKKKRKK SKKSASSESE AENLEAQPQS TVRPEEIPPI PENRFLMRKS PPKADEKERK
   301  NREREREREC NPPNSQPASY QRRLLVTRSG RKIKGRGPRR YRTPSRSRSR DRFRRSETPP
   361  HWRQEMQRAQ RMRVSSGERW IKGDKSELNE IKENQRSPVR VKERKITDHR NVSESPNRKN
   421  EKEKKVKDHK SNSKERDIRR NSEKDDKYKN KVKKRAKSKS RSKSKEKSKS KERDSKHNRN
   481  EEKRMRSRSK GRDHENVKEK EKQSDSKGKD QERSRSKEKS KQLESKSNEH DHSKSKEKDR
   541  RAQSRSRECD ITKGKHSYNS RTRERSRSRD RSRRVRSRTH DRDRSRSKEY HRYREQEYRR
   601  RGRSRSRERR TPPGRSRSKD RRRRRRDSRS SEREESQSRN KDKYRNQESK SSHRKENSES
   661  EKRMYSKSRD HNSSNNSREK KADRDQSPFS KIKQSSQDNE LKSSMLKNKE DEKIRSSVEK
   721  ENQKSKGQEN DHVHEKNKKF DHESSPGTDE DKSG

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against PPIG 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)
0.57
Highest tissue expression
51 nTPM

Expression across tissuesHPA

Tissue

  • bone marrow: 51 nTPM
  • liver: 44 nTPM
  • lymph node: 35 nTPM
  • thymus: 34 nTPM
  • tonsil: 33 nTPM
  • choroid plexus: 33 nTPM

Single-cell type

  • early primary spermatocytes: 351 nCPM
  • oocytes: 299 nCPM
  • syncytiotrophoblasts: 289 nCPM
  • neutrophils: 289 nCPM
  • erythrocyte progenitors: 273 nCPM
  • mast cells: 260 nCPM

Immune cell

  • neutrophil: 40 nTPM
  • naive B-cell: 39 nTPM
  • eosinophil: 37 nTPM
  • naive CD4 T-cell: 34 nTPM
  • memory B-cell: 33 nTPM
  • basophil: 32 nTPM

Brain region

  • hypothalamus: 51 nTPM
  • cerebellum: 49 nTPM
  • cerebral cortex: 46 nTPM
  • midbrain: 43 nTPM
  • white matter: 43 nTPM
  • medulla oblongata: 41 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)
0.32
gnomAD pLI
0.96
gnomAD missense Z
1.72
DepMap mean gene effect
0.02
DepMap dependency class
none

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

KeywordsUniProt

InteractionsUniProt · HPA

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

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

Canonical record: https://seroatlas.com/gene/PPIG. 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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