[Genetic engineering of Pichia pastoris expression system for improved secretion of heterologous proteins--a review].

Due to the potential for producing soluble, correctly folded protein with high yield, Pichia pastoris is currently one of the most effective hosts for the expression of heterologous proteins. However, limitations of expression efficiency are often reported for many different heterologous proteins. Accumulating evidences suggest that protein folding and processing of heterologous protein is a major bottleneck during secretion process in yeast. Apart from optimization of the fermentation process, the current strategies for strain engineering for improving protein secretion are focused mainly on folding and processing, and systematic engineering by high-throughput screening for potential secretion enhancers. This article reviews the genetic engineering progresses of these aspects.