Due to phosphate limitation, the expression of hundreds of proteins is induced and, at the same time, the levels of more than two hundred proteins are reduced [ 10, 24].
One major limitation in the expression of eukaryotic proteins in bacteria is an inability to post-translationally modify the expressed protein.
However, a deeper analysis of the expression patterns of three redundant, fully functional, and simultaneously expressed Sultr1 2 forms (BjSultr1 2a, BjSultr1 2b, BjSultr1 2c) revealed that sulfate limitation induced the expression of all the variants, whilst BjSultr1 2b and BjSultr1 2c only seemed to have the capacity to respond to Cd.
In this study, we observed a significantly positive T-Value of SigB under low oxygen supply, which revealed that oxygen limitation activated the expression of some genes in SigB-regulon (Table 1).
Elsewhere, while Pst in E. coli was demonstrated to have decreased expression in the presence of excessive inorganic phosphate, phosphate limitation induces the expression of Pst[ 29].
A BioLector experiment was conducted to study in detail the general effects of a phosphate limitation on the expression of the fluorescence protein EcFbFP.
M. smegmatis possesses a GlnR homologue (MSMEG5784), with 55% amino acid identity to the S. coelicolor GlnR, with 52 GlnR binding sites during nitrogen limitation controlling the expression of over 100 genes [ 21- 23].
Initially, cell-free expression was restricted by several limitations, especially for the expression of transmembrane proteins or proteins rich in disulfide bonds.
In this study, we demonstrated that mcl-PHA biosynthesis on xylose does not occur when xylA and xylB are expressed even under nitrogen limitation, perhaps because the expression of xylAB channels the metabolic flux to central metabolism such as TCA cycle for cell maintenance or/and to production of side products like acetate, rather than to PHA synthesis.
Another limitation lies in the expression of mHLA-DR results.
Sulfate limitation also induces the expression of microRNA miR395 in a SLIM1-dependent manner [ 22, 23].
