Improve the Protein Synthesis through Engineering the Endoplasmic Reticulum Proliferation Pathway in Pichia Pastoris

Pichia pastoris，one of the most widely used expression system, has been developed as production platform for thousands of proteins successfully, but the productivities of most target proteins were still low. Using the metabolic engineering for the modification of the Pichia pastoris host cell to improve the heterologous protein expression has been becoming a newly research hotspot. Endoplasmic reticulum is the major place for synthesis and folding of the nascent proteins, and the proliferation of endoplasmic reticulum has been thought as one of the necessity to enhance the heterologous protein production. However, rare study has focused on engineering this important organelle for enhancing the protein production in P. pastoris. Previously, the gene encoding DGKpp involved in membrane regeneration and phospholipid metabolism showed significantly upregulated expression levels in the engineered Pichia strains with the capability of high heterologous protein production and it is a new hint to convince us to do the ER proliferation engineering for heterologous protein production. In this study, combining the bioinformatics, metabolic engineering and modern biological techniques, the molecular function of DGKpp on the endoplasmic reticulum proliferation will be explored. Finally, two industrial enzymes will be selected to test their heterologous expression in the ER-proliferated Pichia chassis. 

 Keywrods Metabolic engineering, Pichia pastoris, Endoplasmic reticulum proliferation, phospholipid metabolism