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eIF2 alpha phosphorylation, stress perception, and the shutdown of global protein synthesis in cultured CHO cells

Underhill, Michele F., Birch, John R., Smales, Christopher Mark, Naylor, Louise H. (2005) eIF2 alpha phosphorylation, stress perception, and the shutdown of global protein synthesis in cultured CHO cells. Biotechnology and Bioengineering, 89 (7). pp. 805-814. ISSN 0006-3592. (doi:10.1002/bit.20403) (The full text of this publication is not currently available from this repository. You may be able to access a copy if URLs are provided) (KAR id:6220)

The full text of this publication is not currently available from this repository. You may be able to access a copy if URLs are provided.
Official URL:
http://dx.doi.org/10.1002/bit.20403

Abstract

The perception of environmental stress in animal cells engineered to produce heterologous protein leads to the induction of stress signaling pathways and ultimately apoptosis and cell death. Protein synthesis is regulated in response to various environmental stresses by phosphorylation of the a subunit of the eukaryotic initiation factor 2 (eIF2). In this study we have utilized a model system of Chinese hamster ovary cells engineered to secrete recombinant TIMP-1 protein to investigate the relationship between the cellular rate of protein synthesis, eIF2alpha phosphorylation, cellular stress perception, and the rate of cell specific recombinant protein synthesis. The rate of total protein synthesis was maximal after 48 hours of culture, remaining relatively high until 96 hours of culture, after which a decline was observed. Towards the end of culture a marked increase in labeled secreted protein was observed. Total eIF2alpha expression levels were high during the exponential growth phase and decreased slightly towards the end of culture. On the other hand, the relative expression of phosphorylated eIF2alpha showed a bi-phasic response with a small increase in phosphorylated eIF2alpha observed at 48 hours of culture, and a significant increase at 120 hours post-inoculation. The large increase in phosphorylated elF2alpha coincided with the observed increase in labeled secreted protein and the decline in total cellular protein synthesis. A marked increase in ubiquitination was also observed at 120 hours post-inoculation that coincided with reduced rates of cellular protein synthesis and mRNA translation attenuation. We suggest that eIF2alpha phosphorylation is an indicator of cellular stress perception, which could be exploited in recombinant protein manufacturing to commence feeding and engineering strategies. (C) 2005 Wiley Periodicals, Inc.

Item Type: Article
DOI/Identification number: 10.1002/bit.20403
Subjects: Q Science
Divisions: Divisions > Division of Natural Sciences > Biosciences
Depositing User: Mark Smales
Date Deposited: 04 Sep 2008 22:49 UTC
Last Modified: 16 Nov 2021 09:44 UTC
Resource URI: https://kar.kent.ac.uk/id/eprint/6220 (The current URI for this page, for reference purposes)

University of Kent Author Information

Underhill, Michele F..

Creator's ORCID:
CReDIT Contributor Roles:

Smales, Christopher Mark.

Creator's ORCID: https://orcid.org/0000-0002-2762-4724
CReDIT Contributor Roles:

Naylor, Louise H..

Creator's ORCID:
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