The cold-shock response in mammalian cells: investigating the HeLa cell cold-shock proteome

Abstract

In recent years there have been a number of reports that suggest the sub-physiological (<37 degrees C) temperature in vitro culturing of mammalian cells can result in enhanced heterologous protein production. Despite these reports, the mechanisms by which mammalian cells respond to such conditions are largely unknown. We therefore set out to use a model in vitro culture HeLa cell system to begin investigating the cold-shock response in mammalian cell systems. Sub-physiological temperature cultivation resulted in reduced growth and proliferation and a lower total cell protein content. Proteomic analysis confirmed that HeLa cells actively respond to sub-physiological temperature by up-regulating a number of proteins and immunoblot analysis confirmed that specific proteins are indeed up-regulated in a time and temperature dependent manner. Additional work is likely to improve our understanding of the cold-shock response in mammalian cells and identify candidate target proteins for cell engineering to further enhance heterologous protein production at sub-physiological temperatures.

Fig. 1

Representative 2D-PAGE map from a HeLa cell extract. The gel shown is that from HeLa cells cultured at 10 °C. For further details see text

Fig. 2

Expression of specific target proteins during the in vitro culturing of HeLa cells at 37, 32 and 10 °C over a 48 h period as determined by immunoblotting. For further details see text