Working group (Hassan Hashimi)

This working group within the Laboratory of Molecular Biology of Protists focuses on the evolution of factors that are responsible for giving mitochondria their distinctive shape. Mitochondria are commonly referred to as the powerhouse of the cell. However, it is small subcompartments within the organelle called cristae that give them the ability to provide energy to the cell. Cristae are dynamic, for example changing their shape in animals to facilitate apoptosis (i.e. programmed cell death). These ultrastructures also assume a surprising variety of shapes throughout the diverse eukaryotic tree of life for unknown reasons. Thus, we want to understand how these shapes influence the role of mitochondria as powerhouses, and how they may help to give mitochondria other functions. We also want to determine if the developmental program is shared among these different cristae. Our main model organism is the flagellated protist Trypanosoma brucei, a fascinating organism in its own right. However, we also employ other microbes to answer our questions, such as alphaproteobacteria (the very distant relatives of mitochondria) and ciliates. We take a multidisciplinary approach to addressing these questions, involving among other things transgenic manipulation of cells, electron and fluorescence microscopy, proteomics and lipidomics.