Moderate Expression of Increases Protein Secretion by Saccharomyces cerevisiae.

The yeast is widely used to produce biopharmaceutical proteins. However, the limited capacity of the secretory pathway may reduce its productivity. Here, we increased the secretion of a heterologous α-amylase, a model protein used for studying the protein secretory pathway in yeast, by moderately overexpressing , which is involved in protein translocation from the endoplasmic reticulum to the Golgi apparatus. The moderate overexpression of increased α-amylase secretion by generating more endoplasmic reticulum exit sites. The production of reactive oxygen species resulting from the heterologous α-amylase production was reduced. A genome-wide expression analysis indicated decreased endoplasmic reticulum stress in the strain that moderately overexpressed , which was consistent with a decreased volume of the endoplasmic reticulum. Additionally, fewer mitochondria were observed. Finally, the moderate overexpression of was shown to improve the secretion of two other recombinant proteins, endoglucanase I and glucan-1,4-α-glucosidase, indicating that this mechanism is of general relevance. There is an increasing demand for recombinant proteins to be used as enzymes and pharmaceuticals. The yeast is a cell factory that is widely used to produce recombinant proteins. Our study revealed that moderate overexpression of increased recombinant protein secretion in This new strategy can be combined with other targets to engineer cell factories to efficiently produce protein in the future.