The methylotrophic yeast Pichia pastoris is widely used in the production of recombinant proteins. P. pastoris grows to high cell density, provides tightly controlled methanol-inducible trans gene expression and efficiently secretes heterologous proteins in defined media.
However, during culture of a strain of P. pastoris, recombinantly expressed proteins may be degraded before they can be collected, resulting in a mixture of proteins that includes fragments of recombinantly expressed proteins and a decreased yield of full-length recombinant proteins. What is needed, therefore, are tools and engineered strains to mitigate protein degradation in P. pastoris. 