Organization of the human FK506-binding immunophilin FKBP52 protein gene (FKBP4).

FKBP52 is a widely expressed FK506-binding immunophilin that possesses peptidylprolyl isomerase activity and a tetratricopeptide repeat involved in protein-protein interaction. FKBP52 plays an important role in steroid receptor function and is implicated in other diverse processes, including regulation of transcription, cation channel activity, and gene transfer efficiency. Reported here is the genomic organization of the human FKBP52 gene (FKBP4), which shares all but one of the same exon-intron boundaries as the structurally related immunophilin FKBP51 gene (FKBP5).

The FK506-binding immunophilin FKBP51 is transcriptionally regulated by progestin and attenuates progestin responsiveness.

FKBP51 and FKBP52 are large molecular weight FK506-binding immunophilins that have diverse biochemical functions. Best studied is the role that they play as components of steroid hormone receptors. Differential display and gene array screens have identified FKBP51 as a progestin-inducible gene.