Native-State Stability Determines the Extent of Degradation Relative to Secretion of Protein Variants from Pichia pastoris
2011

Protein Secretion from Pichia pastoris

Sample size: 9 publication Evidence: high

Author Information

Author(s): Whyteside Graham, Alcocer Marcos J. C., Kumita Janet R., Dobson Christopher M., Lazarou Maria, Pleass Richard J., Archer David B.

Primary Institution: School of Biology, University of Nottingham, Nottingham, United Kingdom

Hypothesis

Less stable proteins are targeted for degradation over secretion.

Conclusion

The study shows that the stability of protein variants affects their secretion levels, with less stable variants being retained in the cell and targeted for degradation.

Supporting Evidence

  • Less stable variants of human lysozyme showed lower secretion yields.
  • UPR and ERAD genes were up-regulated in response to less stable protein variants.
  • Intracellular retention of less stable variants was significantly higher than that of more stable variants.
  • Engineering scFv variants improved their secretion by enhancing their stability.

Takeaway

This study found that proteins that are not very stable get stuck in the cell instead of being sent out, which is why we see less of them outside.

Methodology

The researchers expressed mutational variants of human lysozyme in Pichia pastoris and measured the transcription levels of UPR, ERAD, and ER-phagy related genes using qRT-PCR.

Limitations

The study does not provide a formal direct demonstration of ER-phagy induction.

Digital Object Identifier (DOI)

10.1371/journal.pone.0022692

Want to read the original?

Access the complete publication on the publisher's website

View Original Publication