Solution structure of the N-terminal domain of human FKBP38 (FKBP38NTD)
[FKBP8_HUMAN] Constitutively inactive PPiase, which becomes active when bound to calmodulin and calcium. Seems to act as a chaperone for BCL2, targets it to the mitochondria and modulates its phosphorylation state. The BCL2/FKBP8/calmodulin/calcium complex probably interferes with the binding of BCL2 to its targets. The active form of FKBP8 may therefore play a role in the regulation of apoptosis.  
Publication Abstract from PubMed
FKBP38 regulates apoptosis through unique interactions with multiple regulators including Bcl-2. Interestingly, the peptidylprolyl isomerase activity of FKBP38 is only detectable when it binds to calcium-saturated calmodulin (CaM/Ca(2+)). This, in turn, permits the formation of a complex with Bcl-2. FKBP38 thereby provides an important link between isomerase activity and apoptotic pathways. Here, we show that the N-terminal extension (residues 1-32) preceding the catalytic domain of FKBP38 has an autoinhibitory activity. The core isomerase activity of FKBP38 is inhibited by transient interactions involving the flexible N-terminal extension that precedes the catalytic domain. Notably, CaM/Ca(2+) binds to this N-terminal extension and thereby releases the autoinhibitory contacts between the N-terminal extension and the catalytic domain, thus potentiating the isomerase activity of FKBP38. Our data demonstrate how CaM/Ca(2+) modulates the catalytic activity of FKBP38.
Functional role of the flexible N-terminal extension of FKBP38 in catalysis.,Kang C, Ye H, Chia J, Choi BH, Dhe-Paganon S, Simon B, Schutz U, Sattler M, Yoon HS Sci Rep. 2013 Oct 22;3:2985. doi: 10.1038/srep02985. PMID:24145868
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.