Aspergillus niger ireA Gene Mutations for Recombinant Protein Secretion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for increasing the productivity of recombinant protein production in fungal host strains, such as the secretion of heterologous proteins, are limited in efficiency and yield, particularly due to the constraints of existing stress response mechanisms like the unfolded protein response in eukaryotic cells.
Innovation Solution
Introducing specific amino acid substitutions in the ireA gene of Aspergillus niger, specifically at positions 81 and 84, to enhance the secretion of recombinant polypeptides, like glucoamylase from Penicillium oxalicum, by modifying the IreA protein function, thereby improving protein yield and productivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional fungal host strains are used for recombinant protein production, then the production process is simple, but the productivity and yield of secreted polypeptides are limited
Solution Approach 1:
The patent applies parameter changes by introducing specific amino acid substitutions (Ala81Thr and Ala84Thr) in the IreA protein sequence of Aspergillus niger. These targeted changes in the protein's primary structure modify the unfolded protein response signaling pathway, thereby enhancing the secretion capacity and productivity of recombinant polypeptides without requiring complex system-level modifications
Solution Approach 2:
The invention implements local quality by focusing modifications on specific positions (81 and 84) of the IreA protein rather than altering the entire protein or the host genome extensively. The substitutions of alanine residues with threonine at these localized positions create a modified IreA variant that specifically enhances protein secretion while maintaining the overall simplicity of the fungal host system
2Productivity
If the unfolded protein response pathway is left unmodified, then the host cell remains stable, but the secretion efficiency of heterologous proteins is insufficient
Solution Approach 1:
The patent modifies the unfolded protein response pathway by changing specific parameters of the IreA protein - the amino acid residues at positions 81 and 84. These parameter changes in the protein sequence alter the pathway's signaling capacity, enabling enhanced secretion efficiency while the fungal host maintains its fundamental stability and usability
Data Source
AI summary
The instant invention relates to filamentous fungal host cells producing and secreting a heterologous polypeptide of interest, said mutant host cell comprising and expressing a mutated ireA gene or a homologue thereof encoding a modified IreA polypeptide or a homologue thereof, said modified IreA polypeptide or homologue thereof comprising amino acid substitutions in 5 positions corresponding to positions 81 and 84 in the Aspergillus niger IreA amino acid sequence shown in SEQ ID NO:16, as well as methods of producing a polypeptide of interest in said cells and methods for constructing said cells.