P 26 - Dr. Frank Edlich
Mitochondrial morphology regulation by dynamic Bcl-2 protein complexes
| Dr. Frank Edich Institut für Biochemie und Molekularbologie, Universität Freiburg Stefan-Meier-Str. 17 79104 Freiburg Phone: +49 761 203-97482 Fax: +49 761 203-5253 |
Project Summary
Mitochondria accommodate the respiratory chain and essential biosynthetic pathways. Stressinduced mitochondrial damage is confined by fusion and fission evershifting mitochondria from fragmented vesicles to hyperfused networks. Swift and reversible changes of mitochondrial morphology and clearance indicate dynamic control processes, but how mitochondrial quality control is coordinated, remains unknown. Interestingly, Bcl-2 proteins have been shown to interact with the mitochondrial morphology machinery and could stimulate both fusion and fission of mitochondria. The contradictory effects suggested for Bcl-2 proteins on mitochondrial dynamics and the swift regulation of the organelle morphology indicates the dynamic association of Bcl-2 proteins with the multi-protein complexes mediating mitochondrial fusion and fission. The proposed project will explore the influence of Bcl-2 family members on stressdependent regulation of mitochondrial morphology and clearance. Our previous research has established the control of Bcl-2 protein activities by conformational changes on the outer mitochondrial membrane (OMM) of healthy cells. The haracterization of dynamic mitochondrial morphology and mitophagy regulated by Bcl-2 proteins and other factors faces the challenge to link transient changes of protein conformations to the regulation of organelle quality control. Therefore two strategies will be used: (i) stabilization of intermediate conformational states of Bcl-2 proteins and (ii) characterization of protein interactions in living cells by quantitative confocal microscopy techniques. The complementation of constrained protein conformations with quantitative confocal methods will provide a unique insight into rapid changes of multiprotein complexes on the OMM. We aim to establish a new concept of coupling reversible conformational changes of Bcl-2 proteins to mitochondrial dynamics regulation. |