Qualitative and Quantitative Assessment of the Role of Endocytic Regulatory and/or Rab Proteins on Mitochondrial Fusion and Fission.

Mitochondria are the major energy generating organelle in the cell; accordingly mitochondrial homeostasis is key to mitochondrial function. In recent years, new paradigms have uncovered roles for endocytic regulatory proteins in the control of mitochondrial fusion and fission, thus highlighting the utility of techniques for the study of mitochondrial morphology. Herein we detail methods to qualitatively and quantitatively measure the impact of select proteins on mitochondrial fusion and fission in human retinal pigmented epithelial (RPE1) cells. We demonstrate how commercially available small interfering RNA (siRNA) can be used to target various endocytic regulatory proteins, and freely available software can be used to evaluate the impact of these proteins on mitochondria by quantifying their effect on mitochondrial morphology. It is our goal to provide simple protocols that may prove useful for researchers new to the realm of endocytic regulatory proteins and mitochondrial homeostasis.