Giant Peroxisomes: Optogenetic Enlargement and Evaluation of Candidate Organelle For Future Use as Synthetic Organelle
By: Nelson Menjivar
Department: Cellular & Molecular Biology
Faculty Advisor: Dr. Mark Chan
Our understanding of how our cells interact, how they function and how their own molecules act have allowed us to engineer cells for a variety of purposes including chemical synthesis and synthetic tissue formation. Synthetic organelles are at the forefront for deeper understanding and control of cellular reactions, and in this poster we focus on a candidate organelle–the peroxisome–that has previously shown to be capable of compartmentalizing proteins, a necessary ability for usage as a synthetic organelle. In order to more properly utilize the peroxisome for synthetic organelle function, enlargement of the organelle is necessary. Under methanol media, peroxisomes have been shown to increase greatly in size; yet the use of methanol as a carbon source makes it difficult to rapidly culture cells. Using literature and optogenetic size scaling experiments, we find that the peroxisome organelle scales in size with the cell to maintain an overall organelle-to-cell size ratio. Using this knowledge, we can produce larger peroxisomes in budding yeast without the need of methanol media, allowing the peroxisome to become a more viable synthetic organelle. We aim to achieve this through reversible light induced inhibition of the BEM-1 protein in Saccharomyces cerevisiae. Inhibition of this protein has been seen to prevent the budding of daughter cells in S. cerevisiae, resulting in much larger mother cells. We expect to see enlarged organelles as a result of this experiment; specifically enlarged peroxisomes. Successful results will leave us with giant peroxisomes, capable of function as synthetic organelles, without the need of methanol media or other carbon sources. This application will allow for future exploration of enzyme reactions and other chemical experiments within yeast cells, as well deeper insight into the yeast cell as a whole.