PMID: 26248042

Authors:

Guasch A, Aranguren-Ibanez A, Perez-Luque R, Aparicio D, Martinez-Hoyer S, Mulero MC, Serrano-Candelas E, Perez-Riba M, Fita I

Title:

Calcineurin Undergoes a Conformational Switch Evoked via Peptidyl-Prolyl Isomerization.

Journal:

PLoS One. 2015 Aug 6;10(8):e0134569. doi: 10.1371/journal.pone.0134569., eCollection 2015.

Abstract:

A limited repertoire of PPP family of serine/threonine phosphatases with a highly conserved catalytic domain acts on thousands of protein targets to orchestrate myriad central biological roles. A major structural reorganization of human calcineurin, a ubiquitous Ser/Thr PPP regulated by calcium and calmodulin and targeted by immunosuppressant drugs cyclosporin A and FK506, is unveiled here. The new conformation involves trans- to cis-isomerization of proline in the SAPNY sequence, highly conserved across PPPs, and remodels the main regulatory site where NFATc transcription factors bind. Transitions between cis- and trans-conformations may involve peptidyl prolyl isomerases such as cyclophilin A and FKBP12, which are known to physically interact with and modulate calcineurin even in the absence of immunosuppressant drugs. Alternative conformations in PPPs provide a new perspective on interactions with substrates and other protein partners and may foster development of more specific inhibitors as drug candidates.