Pathway candidateNCBI-verifiedprotein-coding

FKBP4

FKBP prolyl isomerase 4

NCBI Gene: 2288 Ensembl GeneCards UniProt: Q02790

Pathway candidate — not linked to PFS or PSSD by any record here

FKBP4 is in the library because it belongs to the receptor chaperones family. No study, report or commentary in the corpus names it, so a variant in FKBP4 is not, by itself, evidence of anything related to post-drug syndromes.

Gene summary

A protein-coding gene on chromosome 12 (steroid receptor chaperones). 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.

Source: NCBI Gene, accessed 2026-10-07.

Protein reference (UniProt)

Protein: Peptidyl-prolyl cis-trans isomerase FKBP4
Function: Immunophilin protein with PPIase and co-chaperone activities. Component of steroid receptors heterocomplexes through interaction with heat-shock protein 90 (HSP90). May play a role in the intracellular trafficking of heterooligomeric forms of steroid hormone receptors between cytoplasm and nuclear compartments. The isomerase activity controls neuronal growth cones via regulation of TRPC1 channel opening. Also acts as a regulator of microtubule dynamics by inhibiting MAPT/TAU ability to promote microtubule assembly. May have a protective role against oxidative stress in mitochondria.
Subcellular location: Cytoplasm, cytosol; Mitochondrion; Nucleus; Cytoplasm, cytoskeleton; Cell projection, axon.
Tissue specificity: Widely expressed.

Source: UniProtKB/Swiss-Prot Q02790, release 2026_03, licensed CC BY 4.0. This is the protein’s normal biology, not evidence about post-drug syndromes; associated conditions are inherited disorders of the gene, not PFS, PSSD or PRSD.

Why its pathway is in the library

Chaperone/co-chaperone control of steroid-receptor folding and sensitivity is a regulatory layer above the receptors themselves, tied to stress-axis signaling.

Written for the whole receptor chaperones family, not for FKBP4 specifically.

Mentioned in 0 corpus records

No corpus record names FKBP4 directly yet. It is in the library because it sits in a pathway the corpus tracks (Receptor chaperones).

Also in steroid receptor chaperones

All 14 genes

Browse by family on the gene families page.

Gene summary

Source: NCBI Gene, accessed 2026-10-07.

Protein reference (UniProt)

Protein: Peptidyl-prolyl cis-trans isomerase FKBP4
Function: Immunophilin protein with PPIase and co-chaperone activities. Component of steroid receptors heterocomplexes through interaction with heat-shock protein 90 (HSP90). May play a role in the intracellular trafficking of heterooligomeric forms of steroid hormone receptors between cytoplasm and nuclear compartments. The isomerase activity controls neuronal growth cones via regulation of TRPC1 channel opening. Also acts as a regulator of microtubule dynamics by inhibiting MAPT/TAU ability to promote microtubule assembly. May have a protective role against oxidative stress in mitochondria.
Subcellular location: Cytoplasm, cytosol; Mitochondrion; Nucleus; Cytoplasm, cytoskeleton; Cell projection, axon.
Tissue specificity: Widely expressed.