Seroatlas · Human Serome Atlas

PPIL1

Peptidyl-prolyl cis-trans isomerase-like 1

Also known as: CYPL1, PPIL1_HUMAN

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

Protein identityUniProt · HPA

UniProt accession
Q9Y3C6
Gene
PPIL1
Ensembl
ENSG00000137168
Chromosome
6
Canonical length
166 aa
Protein class
Disease related genes, Enzymes, Human disease related genes, Metabolic proteins, Plasma proteins, Potential drug targets, Predicted intracellular proteins
Subcellular location
Nucleoli

OverviewNCBI Gene

This gene is a member of the cyclophilin family of peptidylprolyl isomerases (PPIases). The cyclophilins are a highly conserved, ubiquitous family, members of which play an important role in protein folding, immunosuppression by cyclosporin A, and infection of HIV-1 virions. Based on similarity to other PPIases, this protein could accelerate the folding of proteins and might catalyze the cis-trans isomerization of proline imidic peptide bonds in oligopeptides. [provided by RefSeq, Jul 2008]

Canonical amino-acid sequenceUniProt

166 residues, UniProt reviewed canonical sequence.

>Q9Y3C6|PPIL1
     1  MAAIPPDSWQ PPNVYLETSM GIIVLELYWK HAPKTCKNFA ELARRGYYNG TKFHRIIKDF
    61  MIQGGDPTGT GRGGASIYGK QFEDELHPDL KFTGAGILAM ANAGPDTNGS QFFVTLAPTQ
   121  WLDGKHTIFG RVCQGIGMVN RVGMVETNSQ DRPVDDVKII KAYPSG

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against PPIL1 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)
0.26
Highest tissue expression
41 nTPM

Expression across tissuesHPA

Tissue

  • heart muscle: 41 nTPM
  • choroid plexus: 32 nTPM
  • thyroid gland: 31 nTPM
  • retina: 27 nTPM
  • basal ganglia: 26 nTPM
  • hypothalamus: 25 nTPM

Single-cell type

  • oocytes: 88 nCPM
  • migrating cytotrophoblasts: 82 nCPM
  • extravillous trophoblasts: 75 nCPM
  • cytotrophoblasts: 71 nCPM
  • differentiating spermatogonia: 69 nCPM
  • esophageal basal cells: 52 nCPM

Immune cell

  • MAIT T-cell: 20 nTPM
  • naive CD8 T-cell: 16 nTPM
  • gdT-cell: 15 nTPM
  • memory CD8 T-cell: 14 nTPM
  • naive CD4 T-cell: 14 nTPM
  • memory CD4 T-cell: 12 nTPM

Brain region

  • hypothalamus: 30 nTPM
  • spinal cord: 27 nTPM
  • choroid plexus: 27 nTPM
  • medulla oblongata: 26 nTPM
  • pons: 26 nTPM
  • cerebellum: 24 nTPM

DiseaseUniProt · ClinVar · IEDB · PubMed

Four sources answering four different questions about PPIL1.

Disease | AllUniProt

Conditions PPIL1 is implicated in, by any mechanism.

Disease | GeneticClinVar

10 pathogenic / likely-pathogenic of 43 ClinVar records.

Conditions with pathogenic or likely-pathogenic variants.

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)
0.81
gnomAD pLI
0.12
gnomAD missense Z
0.58
DepMap mean gene effect
-0.65
DepMap dependency class
common

Cancer expressionTCGA

Across TCGA tumor cohorts, this protein is over-expressed in roughly 8% 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 PPIL1 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 PPIL1 as an antibody target. Whether an autoantibody or antibody against PPIL1 could matter depends on whether native PPIL1 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

PPIL1 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 PPIL1 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Canonical record: https://seroatlas.com/gene/PPIL1. 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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