FK506-binding protein 8 (FKBP8)

FK506-binding protein 8 (FKBP8, also known as FKBP38) is a member of the immunophilin family. Unlike the classic immunophilins, FKBP8’s peptidyl-prolyl isomerase (PPIase) activity is only activated by Ca²⁺/calmodulin, and it contains unique structural features such as three tetratricopeptide repeat domains and a C-terminal transmembrane domain that anchors it to the endoplasmic reticulum and mitochondrial membranes[3]. FKBP8 is involved in the regulation of apoptosis by modulating mitochondrial pathways, interacting with proteins such as Bcl-2, and is implicated in controlling cell growth and proliferation partly via regulation of mTOR and response to hypoxia[3][6]. It is considered a potential tumor suppressor due to its inverse correlation with cell growth rates in certain cancers. FKBP8 does not function as a typical immunophilin with strong affinity for FK506 or rapamycin, with its structure adapted for additional, possibly neuroprotective, roles[4][7].

Other names

FKBP38FKBP prolyl isomerase 8FKBPr38

Allosteric modulation by Ca²⁺ and calmodulin, which releases inhibition of FKBP8 PPIase activity; Binds and regulates anti-apoptotic protein Bcl-2; Alteration of mTOR signaling pathway, influencing cell survival and growth