Building a programmable protein factory: Recent advances in expression element engineering for Komagataella phaffii

Area of Science:

• * Biotechnology
• * Molecular Biology
• * Synthetic Biology

Background:

• * Komagataella phaffii is a leading eukaryotic host for recombinant protein production.
• * Expression efficiency relies on promoters, terminators, signal peptides, and vectors.
• * Previous reviews analyzed these elements in isolation, hindering integrated design.

Purpose of the Study:

• * To provide a unified analysis of recent progress in K. phaffii genetic elements.
• * To establish practical guidelines for rational expression cassette design.
• * To identify knowledge gaps for future strain engineering.

Main Methods:

• * Comprehensive review of promoter engineering strategies (e.g., remodeling, chimeric construction).
• * Systematic characterization of transcription terminator activity ranges.
• * Analysis of signal peptide engineering techniques (e.g., directed evolution, fusion).
• * Overview of evolving expression vector technologies (e.g., MoClo, CRISPR, OPENPichia).

Main Results:

• * Expanded promoter repertoire beyond classical options.
• * Demonstrated significant variation in terminator activity impacting protein yield.
• * Identified signal peptide optimization as cargo-dependent, yielding up to 14-fold improvements.
• * Highlighted advancements in vector systems enabling efficient gene integration.

Conclusions:

• * Integrated framework for designing K. phaffii expression cassettes.
• * Practical guidelines for combinatorial element selection.
• * Identified need for quantitative models and standardized benchmarking for K. phaffii strain engineering.