This may be important at lower temperatures, because they stabilize the RNA secondary structures, and this stabilization is a major detrimental physiological effect of temperature downshift.
This promoter drives high levels of protein expression, comparable to the commonly used T7-system, but is induced by a downshift in temperature rather than addition of an exogenous chemical inducer [ 9, 10].
The lower heat-induced rise of F0 fluorescence recorded in ssadh mutants as well as the downshift of the F0/Temperature curve to lower temperature shows that photosystem II is impaired in ssadh plants possibly due to high ROI levels.
Recently, activation of the HOG pathway upon a downshift in temperature (30 to 12°C) was monitored in S. cerevisiae, whereas in Schizosaccharomyces pombe the Sty1p MAP-kinase (the Hog1p homolog) lead to the activation of several cold-induced genes [ 35, 36].
Microorganisms differ in responding to a sudden downshift in temperature and this, in turn, impacts their metabolic processes and can cause various structural modifications.
Interestingly, all of these genes (except gyrA) encode class I shock proteins, which are induced at high levels after a shift to a lower temperature (deaD is more than 8-fold up-regulated at 30°C) whereas class II shock proteins are induced a few-fold from their steady-state levels after a downshift in temperature [20].
On the other hand, it was also found that the Sln1 branch of the HOG pathway is activated when membrane fluidity is reduced by a rapid downshift in temperature to <10° or by dimethyl sulfoxide treatment (Hayashi and Maeda 2006; Panadero et al. 2006).
Furthermore, an obvious downshift of the 2D-band of the low-temperature samples (approximately 2,708 cm−1) could be seen, which should be compared with approximately 2,722 cm−1 for high-temperature ones.
In contrast, the conjugated enzyme was essentially stable at 25°C and underwent progressive destabilization on increasing temperature, suggestive of a substantial downshift of the stability optimum.
This temperature was estimated from G band downshift of the carbon nanotube caused due to the bond loosening due to thermal expansion of the bonds.
