Reinforcement strategies of chassis cell secretory pathway for improving heterologous protein production

Abstract

The production of heterologous proteins via microbial secretion is currently a prominent focus in biological product development. However, the full realization of this method remains hindered by limited understanding of the protein secretion mechanism with in target microorganisms. To enhance protein production, microbial chassis cell are being reinforced via synthetic biology and metabolic engineering, proving highly efficient. Among microorganisms, gram-positive bacteria are widely employed due to their absence of an outer membrane, facilitating the production of various secreted proteins, including industrial enzymes, functional nutrients, and medical peptides. Fungi also play a pivotal role in secreted protein production, thanks to their efficient post-translational modification and secretory capabilities. In this context, we highlighted the secretion mechanism of heterologous proteins in B. subtilis and P. pastoris, two classical secretory systems. Their proficient protein secretion, low number of extracellular heteroproteins, and convenient genetic manipulation make them both highly preferable as chassis cells. On this basis, the strategies of enhancing protein secretory pathway after synthesis through genetic engineering were elaborated, and the application of some cutting-edge technologies in this pathway were expanded.

Keywords

• Bacillus subtilis
• Pichia pastoris
• Heterologous protein
• Secretion pathways