ECLIPSED DUAL DISTRIBUTION OF MITOCHONDRIAL PROTEINS IN EUKARYOTES: UBIQUITINATION IN YEAST MITOCHONDRIA AS A PARADIGM

Abstract

Mitochondria are multifunctional, vital organelles of eukaryotic cells. Previous studies of Ophry Pines' lab demonstrate that dual targeting of mitochondrial proteins is a highly abundant phenomenon using Saccharomyces cerevisiae as the model organism. The studies of the present thesis indicate that a significant fraction of cellular proteins, much more than previously assumed, are eclipsed dual targeted and may be functional in mitochondria. As suggested by our data, ubiquitination in this organelle is achieved by eclipsed targeted components of the ubiquitination machinery. Additionally, the iTRAQ proteomics approach applied in the current thesis sets the ground for systematic screening of dual targeting regulation. We believe that the present studies will have an impact on discovery of new molecular events by which dual targeting, especially eclipsed dual targeting, occurs in the cell and will hopefully advance our understanding of the mitochondrial function and reshape our perception of protein subcellular compartmentalization.