Cyclophilin D reduces Ca2+ sequestration by complement 1q binding protein.

ABSTRACT: Complement 1q binding protein (C1qBP) and cyclophilin D (CypD) are mitochondrial matrix proteins; C1qBP has been implicated in many cellular processes, including the regulation of oxidative phosphorylation, and CypD is widely associated with the regulation of mitochondrial permeability transition pore (mPTP) opening. In this study, C1qBP and CypD were shown, in vitro, to form a stable protein-protein complex. CypD-C1qBP interaction was disrupted by cyclosporin A and compromised by mutations of the CypD active site residues R55 and R82. AlphaFold protein modelling revealed that the large negatively charged surface of C1qBP binds to the positive surface of CypD. This electrostatically driven interaction was confirmed by the pH dependence of the protein-protein interaction, with lower affinit

SUBMITTER: Adegbite O 

PROVIDER: S-EPMC12751049 | biostudies-literature | 2025 Dec

REPOSITORIES: biostudies-literature