FROM WORM TO YEAST AND BACK: INVESTIGATING ANIMAL PAR POLARITY WITH RECONSTITUTION

Abstract

Cell polarity, the asymmetric organization of components within cells, is essential for the normal functioning and survival of many cell types. The key regulators of polarity in animal cells include the well-conserved partitioning-defective (PAR) proteins, which are generally segregated into two distinct compartments on the cell cortex. I reconstituted the C. elegans embryonic polarity networks in a heterologous cell system, Saccharomyces cerevisiae. Consistent with the pattern in C. elegans zygotes, the complexes of PAR proteins introduced in yeast cells yielded a mutually-segregated distribution at the cell cortex. To further investigate the biochemical properties of one of the PAR proteins, PAR-3, in the context of physiological conditions, I used C. elegans intestine precursor cells (E cells) as a model system. This project combines the advantages of reverse engineering system established in budding yeast and C. elegans embryo in vivo to understand the principles of cell polarity and novel properties of PAR-3.