Elena-Real, Carlos ADíaz-Quintana, AntonioGonzález-Arzola, KatiuskaVelázquez-Campoy, AdriánOrzáez, MarLópez-Rivas, AbelardoGil-Caballero, SergioDe la Rosa, Miguel ÁDíaz-Moreno, Irene2023-01-252023-01-252018-03-06http://hdl.handle.net/10668/12211Apoptosis is a highly regulated form of programmed cell death, essential to the development and homeostasis of multicellular organisms. Cytochrome c is a central figure in the activation of the apoptotic intrinsic pathway, thereby activating the caspase cascade through its interaction with Apaf-1. Our recent studies have revealed 14-3-3ε (a direct inhibitor of Apaf-1) as a cytosolic cytochrome c target. Here we explore the cytochrome c / 14-3-3ε interaction and show the ability of cytochrome c to block 14-3-3ε-mediated Apaf-1 inhibition, thereby unveiling a novel function for cytochrome c as an indirect activator of caspase-9/3. We have used calorimetry, NMR spectroscopy, site mutagenesis and computational calculations to provide an insight into the structural features of the cytochrome c / 14-3-3ε complex. Overall, these findings suggest an additional cytochrome c-mediated mechanism to modulate apoptosome formation, shedding light onto the rigorous apoptotic regulation network.enAttribution 4.0 Internationalhttp://creativecommons.org/licenses/by/4.0/14-3-3 ProteinsAmino Acid MotifsApoptotic Protease-Activating Factor 1Caspase 3Caspase 9Cytochromes cCytosolEnzyme ActivationHumansProtein Bindingresearch article29511177open access10.1038/s41419-018-0408-12041-4889PMC5840378https://www.nature.com/articles/s41419-018-0408-1.pdfhttps://www.ncbi.nlm.nih.gov/pmc/articles/PMC5840378/pdf