Analysis of mitochondrial dynamics; The role of the fusion protein Ugo1 and analysis of the mechanism of mitochondrial division

Mitochondrial dynamics are essential processes that function to maintain the organelle in cells. The processes of mitochondrial division and fusion are unique and the exact mechanistic details of how these double membraned organelles carry out these processes are not completely understood. In mitochondrial division in yeast, two dynamin related GTPases (DRPs) located on the outer and inner membrane respectively are thought to regulate the membrane remodeling events required to fusion two adjacent organelles. The third division component, Ugo1, is thought to act as an adaptor linking outer and inner membrane fusion complexes in some way. This dissertation provides evidence that Ugo1 does indeed interact with both the outer and inner membrane components through study of temperature sensitive ugo1 mutants. In contrast to the machineries that fuse mitochondria, division of mitochondrial membranes is regulated at the outer membrane by three components: Dnm1, Fis1, and Mdv1. The outer membrane DRP, Dnm1, is thought to be the master regulator of the division process. This dissertation provides evidence that furthers our understanding of the mechanism of Dnm1 assembly through analysis of the mutant protein Dnm1G385D and also presents evidence for the discovery of a new inhibitor of mitochondrial division DRPs that specifically targets the yeast and mammalian cell DRPs, Dnm1 and Drp1.