Systematic Reconstruction of Calcium Signaling Networks in Mitochondria

• Applicant: Professorin Fabiana Perocchi, Ph.D.
• Subject Area: Cell Biology
• Term: from 2012 to 2018
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 221568619

Mitochondria are an integral part of calcium (Ca2+)-mediated signal transduction cascades. The organelle can take up, buffer, and release Ca2+ ions during physiological and pathological elevations of intracellular Ca2+ to shape cytosolic Ca2+ transients, stimulate ATP production, and regulate cell death. The basic mechanisms of mitochondrial Ca2+ homeostasis have been firmly established for decades, yet, we know only a handful of the proteins responsible: what is the fate of Ca2+ inside mitochondria? How are the Ca2+ signals conveyed and translated into an adequate mitochondrial response? What happens when mitochondrial Ca2+ handling is compromised and how can we prevent deleterious effects? To address these questions we will combine an evolutionary genomics approach with loss-of-function genetic and chemical screens and in-depth analyses of mitochondrial Ca2+ physiology. By reconstructing and comparing the evolutionary history of mammalian mitochondrial proteins with known Ca2+ signaling components, we will predict novel candidate genes for the mitochondrial Ca2+ toolkit. We will test all candidates by complementary assays of Ca2+ kinetics and bioenergetics. Essential protein set for several mitochondrial signaling modules will be characterized by exogenous expression in mitochondria of S. cerevisiae, that lack analogous activities. This strategy will also provide us with a specific in vitro assay to search for chemical modulators of mitochondrial Ca2+ uptake. By expanding our recent molecular characterization of the mitochondrial uptake machinery, the proposed research has the potential to shed light on yet unidentified Ca2+ signaling networks of mitochondria that could be targeted pharmacologically in the treatment of numerous human diseases.

• DFG Programme: Independent Junior Research Groups
• Major Instrumentation: Extracellular Flux Analyzer ; Luminescence Microplate Counter
• Instrumentation Group: 3100 Immunochemische Bestimmungsgeräte (außer Immunelektrphorese 141) ; 3560 Warburg-Apparaturen, Zellstoffwechsel-Analysengeräte