34 research outputs found
Correlation of gene expression and protein production rate - a system wide study
<p>Abstract</p> <p>Background</p> <p>Growth rate is a major determinant of intracellular function. However its effects can only be properly dissected with technically demanding chemostat cultivations in which it can be controlled. Recent work on <it>Saccharomyces cerevisiae </it>chemostat cultivations provided the first analysis on genome wide effects of growth rate. In this work we study the filamentous fungus <it>Trichoderma reesei </it>(<it>Hypocrea jecorina</it>) that is an industrial protein production host known for its exceptional protein secretion capability. Interestingly, it exhibits a low growth rate protein production phenotype.</p> <p>Results</p> <p>We have used transcriptomics and proteomics to study the effect of growth rate and cell density on protein production in chemostat cultivations of <it>T. reesei</it>. Use of chemostat allowed control of growth rate and exact estimation of the extracellular specific protein production rate (SPPR). We find that major biosynthetic activities are all negatively correlated with SPPR. We also find that expression of many genes of secreted proteins and secondary metabolism, as well as various lineage specific, mostly unknown genes are positively correlated with SPPR. Finally, we enumerate possible regulators and regulatory mechanisms, arising from the data, for this response.</p> <p>Conclusions</p> <p>Based on these results it appears that in low growth rate protein production energy is very efficiently used primarly for protein production. Also, we propose that flux through early glycolysis or the TCA cycle is a more fundamental determining factor than growth rate for low growth rate protein production and we propose a novel eukaryotic response to this i.e. the lineage specific response (LSR).</p
Chemotaxonomic Fingerprinting of Chilean Lichens Through Maldi and Electrospray Ionization Mass Spectrometry
Largeâscale changes in abundance of terricolous bryophytes and macrolichens in Finland
Identification of some lichenised fungi from James Ross Island (Antarctic Peninsula) using nrITS markers
The collections of threatened bryophytes from Ladoga Karelia (Russia) in Finnish herbaria
Changes in the abundance, composition and species richness of mountain vegetation in relation to summer grazing by reindeer
Optimization of the secretion pathway for heterologous proteins in Bacillus subtilis
Secretion of homologous proteins in large amounts has been accomplished for many proteins, but no efficient secretion system has been described so far which can be generally applied for heterologous proteins. The objective of this review article is to compare the three major secretion pathways in E. coli and in B. subtilis and review the stages of conversion of the secreted proteins from the unfolded polypeptide chains into the correctly folded and fully active protein. Furthermore, bottlenecks in the production of heterologous proteins and the ways to resolve them are briefly discussed