Seroatlas · Human Serome Atlas

FKBP4

Peptidyl-prolyl cis-trans isomerase FKBP4

Also known as: FKBP4_HUMAN, FKBP52, FKBP59

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

Protein identityUniProt · HPA

UniProt accession
Q02790
Gene
FKBP4
Ensembl
ENSG00000004478
Chromosome
12
Canonical length
459 aa
Protein class
Enzymes, Metabolic proteins, Plasma proteins, Predicted intracellular proteins
Subcellular location
Nucleoplasm,Cytosol
Quaternary structure
Homodimer

OverviewNCBI Gene

The protein encoded by this gene is a member of the immunophilin protein family, which play a role in immunoregulation and basic cellular processes involving protein folding and trafficking. This encoded protein is a cis-trans prolyl isomerase that binds to the immunosuppressants FK506 and rapamycin. It has high structural and functional similarity to FK506-binding protein 1A (FKBP1A), but unlike FKBP1A, this protein does not have immunosuppressant activity when complexed with FK506. It interacts with interferon regulatory factor-4 and plays an important role in immunoregulatory gene expression in B and T lymphocytes. This encoded protein is known to associate with phytanoyl-CoA alpha-hydroxylase. It can also associate with two heat shock proteins (hsp90 and hsp70) and thus may play a role in the intracellular trafficking of hetero-oligomeric forms of the steroid hormone receptors. This protein correlates strongly with adeno-associated virus type 2 vectors (AAV) resulting in a significant increase in AAV-mediated transgene expression in human cell lines. Thus this encoded protein is thought to have important implications for the optimal use of AAV vectors in human gene therapy. The human genome contains several non-transcribed pseudogenes similar to this gene. [provided by RefSeq, Sep 2008]

Canonical amino-acid sequenceUniProt

459 residues, UniProt reviewed canonical sequence.

>Q02790|FKBP4
     1  MTAEEMKATE SGAQSAPLPM EGVDISPKQD EGVLKVIKRE GTGTEMPMIG DRVFVHYTGW
    61  LLDGTKFDSS LDRKDKFSFD LGKGEVIKAW DIAIATMKVG EVCHITCKPE YAYGSAGSPP
   121  KIPPNATLVF EVELFEFKGE DLTEEEDGGI IRRIQTRGEG YAKPNEGAIV EVALEGYYKD
   181  KLFDQRELRF EIGEGENLDL PYGLERAIQR MEKGEHSIVY LKPSYAFGSV GKEKFQIPPN
   241  AELKYELHLK SFEKAKESWE MNSEEKLEQS TIVKERGTVY FKEGKYKQAL LQYKKIVSWL
   301  EYESSFSNEE AQKAQALRLA SHLNLAMCHL KLQAFSAAIE SCNKALELDS NNEKGLFRRG
   361  EAHLAVNDFE LARADFQKVL QLYPNNKAAK TQLAVCQQRI RRQLAREKKL YANMFERLAE
   421  EENKAKAEAS SGDHPTDTEM KEEQKSNTAG SQSQVETEA

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against FKBP4 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)
0.32
Highest tissue expression
97 nTPM

Expression across tissuesHPA

Tissue

  • cerebellum: 97 nTPM
  • esophagus: 67 nTPM
  • skeletal muscle: 66 nTPM
  • kidney: 60 nTPM
  • choroid plexus: 58 nTPM
  • liver: 56 nTPM

Single-cell type

  • late primary spermatocytes: 283 nCPM
  • syncytiotrophoblasts: 277 nCPM
  • breast lactating cells: 261 nCPM
  • esophageal apical cells: 252 nCPM
  • esophageal suprabasal cells: 243 nCPM
  • esophageal basal cells: 242 nCPM

Immune cell

  • basophil: 17 nTPM
  • non-classical monocyte: 16 nTPM
  • naive B-cell: 14 nTPM
  • memory B-cell: 14 nTPM
  • MAIT T-cell: 14 nTPM
  • naive CD8 T-cell: 14 nTPM

Brain region

  • white matter: 183 nTPM
  • cerebellum: 159 nTPM
  • cerebral cortex: 143 nTPM
  • pons: 115 nTPM
  • hypothalamus: 112 nTPM
  • thalamus: 107 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)
0.5
gnomAD pLI
0.16
gnomAD missense Z
1.21
DepMap mean gene effect
-0.02
DepMap dependency class
selective

Cancer expressionTCGA

Across TCGA tumor cohorts, this protein is over-expressed in roughly 9% 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 FKBP4 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 FKBP4 as an antibody target. Whether an autoantibody or antibody against FKBP4 could matter depends on whether native FKBP4 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

FKBP4 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 FKBP4 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Canonical record: https://seroatlas.com/gene/FKBP4. 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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