A Chromosomal Plasmid for Pichia Pastoris
Pichia pastoris and Centromeric Plasmids
Pichia pastoris is a species of yeast that is widely used in the biotechnical industry as a vehicle for the production of recombinant proteins. However, it lacks a centromeric plasmid — a genetic structure within the cell that replicates as though it is a small independent chromosome. By inserting a centromeric sequence into a plasmid within a cell, it is possible to simultaneously provide P. pastoris with the stability of a chromosome and the flexibility of a plasmid.
What We Created
For the 2018 iGEM competition, the University of Chicago GeneHackers are continuing to develop a centromeric plasmid for Pichia pastoris. Centromeric plasmids combine the stability of a chromosome and the flexibility of a plasmid to create the perfect tool for the biotechnical industry. Pichia pastoris, a strain of yeast often used in this field, lacks a centromeric plasmid, which limits the research that can be done with this species. Such a plasmid will be useful for a multitude of purposes, including bioengineering and industrial applications. We have found several putative sequences within the genome of Pichia pastoris that will allow our bacterial-yeast shuttle vector to integrate into the yeast's chromosomes. Upon creating our centromeric plasmid, we will perform fluorescence and sectoring assays to ensure the DNA is distributed evenly among daughter cells of the yeast, and we will work to optimize the P. pastoris chromosomal sequence. Overall, our goal for this year is to complete our P. pastoris centromeric plasmid.
As stated before, our new plasmid will be useful for a multitude of purposes, including bioengineering and industrial applications. Today's science focuses on E. Coli because it is cheaper and easier to use. However, yeast is superior to E.Coli because it offers the advantages of eukaryotic membrane-targeting machinery, chaperones, and faithful post translational modifications. With the success of our project, a wide variety of labs and companies can use P. pastoris to solve problems.