Mitochondria are rod-shaped organelles that supply the cell with energy by changing nutrients into adenosine triphosphate (ATP). The fragmentation or fission of mitochondria decreases the energy within the cell. Due to the lack of energy, the cell becomes unhealthy and may die. We are interested in the effect of mitochondrial fission in neurons in relation to damage caused by stroke.

The mitochondrial dynamics protein 51 (MiD51) is located in the outer membrane of mitochondria. Recently, it was published that MiD51 controls the shape of mitochondria by preventing mitochondrial fission and by promoting mitochondrial fusion. Interactions between dynamin-related protein 1 (Drp1), mitochondrial fission 1 protein (Fis1), and MiD51 prevent mitochondrial fission. Another fragmentation system in the mitochondria is the mitochondrial fission factor (Mff) and Drp1 interaction. The MiD51 and Fis1 system might compete with the MFF and Drp1 system. In order to study the interaction of MiD51 and Fis1, we study two versions of the MiD51 protein, MiD51 47-463 and MiD51 47-304; one version of the MiD51 is longer than the other version. We want see what effect the different lengths will have on the way the proteins bind. Through a process called subcloning, we create plasmid vectors. Specifically, polymerase chain reaction (PCR) is used to amplify the target gene. Once the plasmid vector is created, it is transformed in bacterial cells and replicated. After the subcloning process, the proteins are expressed in BL21 chemically competent E.coli cells. Then, we performed pull-downs on MiD51 and Fis1, in order to see if these proteins interact and if they bind. A pull-down analysis is an in vitro technique used to study the interaction between proteins. If MiD51 binds with Fis1, we predict this interaction affects the activity of Drp1.