Imbalance of heterologous protein folding and disulfide bond formation rates yields runaway oxidative stress
Artikel i vetenskaplig tidskrift, 2012

Background The protein secretory pathway must process a wide assortment of native proteins for eukaryotic cells to function. As well, recombinant protein secretion is used extensively to produce many biologics and industrial enzymes. Therefore, secretory pathway dysfunction can be highly detrimental to the cell and can drastically inhibit product titers in biochemical production. Because the secretory pathway is a highly-integrated, multi-organelle system, dysfunction can happen at many levels and dissecting the root cause can be challenging. In this study, we apply a systems biology approach to analyze secretory pathway dysfunctions resulting from heterologous production of a small protein (insulin precursor) or a larger protein (α-amylase). Results HAC1-dependent and independent dysfunctions and cellular responses were apparent across multiple datasets. In particular, processes involving (a) degradation of protein/recycling amino acids, (b) overall transcription/translation repression, and (c) oxidative stress were broadly associated with secretory stress. Conclusions Apparent runaway oxidative stress due to radical production observed here and elsewhere can be explained by a futile cycle of disulfide formation and breaking that consumes reduced glutathione and produces reactive oxygen species. The futile cycle is dominating when protein folding rates are low relative to disulfide bond formation rates. While not strictly conclusive with the present data, this insight does provide a molecular interpretation to an, until now, largely empirical understanding of optimizing heterologous protein secretion. This molecular insight has direct implications on engineering a broad range of recombinant proteins for secretion and provides potential hypotheses for the root causes of several secretory-associated diseases.

protein production

unfolded protein response

Protein secretion

HAC1

oxidative stress

Författare

Keith Tyo

Chalmers, Kemi- och bioteknik, Livsvetenskaper, Systembiologi

Zihe Liu

Chalmers, Kemi- och bioteknik, Livsvetenskaper, Systembiologi

Dina Petranovic Nielsen

Chalmers, Kemi- och bioteknik, Livsvetenskaper, Systembiologi

Jens B Nielsen

Chalmers, Kemi- och bioteknik, Livsvetenskaper, Systembiologi

BMC Biology

1741-7007 (ISSN)

Vol. 10 Art. no 16- 16

Ämneskategorier

Biologiska vetenskaper

Fundament

Grundläggande vetenskaper

Styrkeområden

Livsvetenskaper och teknik

DOI

10.1186/1741-7007-10-16