This title appears in the Scientific Report :
2012
Please use the identifier:
http://hdl.handle.net/2128/18544 in citations.
Regulatorische Aspekte der Expression und Sekretion heterologer Proteine in $\textit{Corynebacterium glutamicum}$
Regulatorische Aspekte der Expression und Sekretion heterologer Proteine in $\textit{Corynebacterium glutamicum}$
The impact of biotechnological production of heterologous proteins is steadily increasing. Herein secretory protein production is advantageous since it saves both time and money during downstream processing. $\textit{Corynebacterium glutamicum}$ is a promising host organism for Sec- as well as Tat-d...
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Personal Name(s): | Chattopadhyay, Ava Rebecca (Corresponding author) |
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Contributing Institute: |
Biotechnologie; IBG-1 |
Imprint: |
Jülich
Forschungszentrum Jülich GmbH Zentralbibliothek, Verlag
2013
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Physical Description: |
179 S. |
Dissertation Note: |
Dissertation, Heinrich-Heine-Universität Düsseldorf, 2012 |
ISBN: |
978-3-89336-845-7 |
Document Type: |
Book Dissertation / PhD Thesis |
Research Program: |
ohne Topic |
Series Title: |
Schriften des Forschungszentrums Jülich. Reihe Gesundheit / Health
62 |
Subject (ZB): | |
Link: |
OpenAccess |
Publikationsportal JuSER |
The impact of biotechnological production of heterologous proteins is steadily increasing. Herein secretory protein production is advantageous since it saves both time and money during downstream processing. $\textit{Corynebacterium glutamicum}$ is a promising host organism for Sec- as well as Tat-dependent secretory protein production. In this work on the one hand the transcriptional response to Tatdependent secretion of model proteins in $\textit{C. glutamicum}$ was analysed to ideally identify bottlenecks within this production strategy. On the other hand the twocomponent systems CgtRS2 and CgtSR7 of $\textit{C. glutamicum}$ were studied as there was evidence of involvement of these systems in regulation of transcriptional responses induced by Sec-dependent protein secretion. The following results were obtained. i. Studying several variants of fusion proteins containing different Tat signal peptides $\textit{C. glutamicum}$ did hardly show any response to Tat-dependent secretion on the transcriptional level. Only upon secretion of one single variant of a model protein in combination with a Tat signal peptide there was repression of two genes encoding putative Tat substrates. This indicates a Tat translocase nearly at full-capacity during secretion of this variant. The examination of four further variants of fusion proteins containing Tat signal peptides did not result in transcriptional responses to Tatdependent secretion. ii. However, a $\textit{C. glutamicum tatAC}$ deletion mutant examined to simulate a Tat translocase completely used to capacity showed several transcriptional differences in comparison to a $\textit{C. glutamicum qcrA}$ deletion mutant which is deficient of the most important Tat substrate contributing to functionality of the bc1aa3 supercomplex. Besides deficiency of the more effective respiration branch, lack of the functional Tat translocase caused oxidative stress and slight copper stress in the cell. Since the simulation of a Tat translocase at maximum capacity caused oxidative stress in contrast to secretion of all studied variants of fusion proteins containing Tat signal peptides, the dimension of expression and secretion of the variants of fusion proteins seems not to be sufficiently high to use the Tat translocase’s full capacity. This indicates the possibility to express and secrete significantly higher amounts of heterologous protein in $\textit{C. glutamicum}$ compared to the amounts achieved in this work before complete capacity utilisation of the Tat translocase occurs. [...] |