Seroatlas · Human Serome Atlas

PPIB

Peptidyl-prolyl cis-trans isomerase B

Also known as: B, CYP-S1, CYPB, OI9, PPIase, PPIB_HUMAN, SCYLP

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

Protein identityUniProt · HPA

UniProt accession: P23284
Gene: PPIB
Ensembl: ENSG00000166794
Chromosome: 15
Canonical length: 216 aa
Protein class: Disease related genes, Enzymes, Human disease related genes, Metabolic proteins, Plasma proteins, Potential drug targets, Predicted intracellular proteins, Predicted secreted proteins
Subcellular location: Nucleoplasm,Endoplasmic reticulum
Secretome location: Secreted to blood

OverviewNCBI Gene

The protein encoded by this gene is a cyclosporine-binding protein and is mainly located within the endoplasmic reticulum. It is associated with the secretory pathway and released in biological fluids. This protein can bind to cells derived from T- and B-lymphocytes, and may regulate cyclosporine A-mediated immunosuppression. Variants have been identified in this protein that give rise to recessive forms of osteogenesis imperfecta. [provided by RefSeq, Oct 2009]

Canonical amino-acid sequenceUniProt

216 residues, UniProt reviewed canonical sequence.

>P23284|PPIB
     1  MLRLSERNMK VLLAAALIAG SVFFLLLPGP SAADEKKKGP KVTVKVYFDL RIGDEDVGRV
    61  IFGLFGKTVP KTVDNFVALA TGEKGFGYKN SKFHRVIKDF MIQGGDFTRG DGTGGKSIYG
   121  ERFPDENFKL KHYGPGWVSM ANAGKDTNGS QFFITTVKTA WLDGKHVVFG KVLEGMEVVR
   181  KVESTKTDSR DKPLKDVIIA DCGKIEVEKP FAIAKE

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against PPIB 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: 867 nTPM

Expression across tissuesHPA

Tissue

liver: 867 nTPM
epididymis: 848 nTPM
pancreas: 776 nTPM
thyroid gland: 630 nTPM
ovary: 596 nTPM
cervix: 575 nTPM

Single-cell type

extravillous trophoblasts: 2,057 nCPM
decidual stromal cells: 1,668 nCPM
plasma cells: 1,608 nCPM
syncytiotrophoblasts: 1,390 nCPM
epididymal principal cells: 1,105 nCPM
migrating cytotrophoblasts: 897 nCPM

Immune cell

plasmacytoid DC: 2,650 nTPM
total PBMC: 1,513 nTPM
MAIT T-cell: 934 nTPM
myeloid DC: 932 nTPM
gdT-cell: 932 nTPM
memory B-cell: 831 nTPM

Brain region

white matter: 155 nTPM
medulla oblongata: 149 nTPM
hypothalamus: 145 nTPM
thalamus: 144 nTPM
choroid plexus: 144 nTPM
cerebellum: 123 nTPM

DiseaseUniProt · ClinVar · IEDB · PubMed

Four sources answering four different questions about PPIB.

Disease | AllUniProt

Conditions PPIB is implicated in, by any mechanism.

Osteogenesis imperfecta 9 (OI9) MIM:259440

Disease | GeneticClinVar

22 pathogenic / likely-pathogenic of 210 ClinVar records.

Conditions with pathogenic or likely-pathogenic variants.

Disease | ImmuneIEDB

Conditions an epitope on PPIB was assayed in.

prostate adenocarcinoma B and T cell
prostate cancer B and T cell
cancer B and T cell
castration-resistant prostate carcinoma B and T cell
triple-receptor negative breast cancer B and T cell
Her2-receptor negative breast cancer B and T cell
Her2-receptor positive breast cancer B and T cell
cervical squamous cell carcinoma B and T cell
gastric adenocarcinoma B and T cell
atopic dermatitis B cell
biliary tract cancer B and T cell
esophageal cancer B and T cell
colorectal cancer B and T cell
leiomyosarcoma B and T cell
osteosarcoma B and T cell
synovial sarcoma B and T cell
lung cancer B and T cell
prostatic urethral cancer B and T cell
pancreatic carcinoma B cell
lung small cell carcinoma B cell

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): 1.6
gnomAD pLI: 0
gnomAD missense Z: 0.3
DepMap mean gene effect: -0.1
DepMap dependency class: selective

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

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

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