Feierstunde aus Anlass des Tages der Deutschen Einheit und der Wiederbegründung des Freistaates Sachsen im Plenarsaal des Sächsischen Landtages.

Veranstaltung zum Tag der Deutschen Einheit im Sächsischen Landtag gemeinsam mit dem Streichquartett der Kammerphilharmonie Dresden.

Wie an jedem 3. Oktober werden am Nachmittag wieder Tausende Menschen den Tag der offenen Tür nutzen und das Parlament der Sachsen, das Herz der sächsischen Demokratie, erkunden.

Am 3. Oktober 1989, auf den Tag genau vor 30 Jahren, setzte deshalb die DDR-Staatsführung den pass- und visafreien Verkehr zwischen der DDR und der Tschechoslowakei aus. Die Grenzschließung zum Nachbarland war eine der vielen Bankrotterklärungen der kommunistischen Diktatur. Die SED-Führung wusste erneut kein anderes Mittel, um die Abstimmung mit den Füßen zu stoppen, als das Einsperren der Bevölkerung. Es herrschte »Panik im Olymp«.

Feierstunde des Sächsischen Landtags aus Anlass des 30. Tages der Deutschen Einheit und des 30. Jubiläums der Wiederbegründung des Freistaates Sachsen.

Der 3. Oktober 1990 als Tag der Deutschen Einheit ist für uns Sachsen von doppelter historischer Bedeutung. Er markiert eben auch die Wiedergründung unseres Freistaates, geboren aus der Friedlichen Revolution, aus einer Freiheitsrevolution, die die Spaltung Deutschlands und Europas überwand.

Seit 33 Jahren ist unser Land wiedervereinigt in Freiheit und Demokratie. Dieser 3. Oktober ist ein Tag der Freude, ein Tag zum Feiern. Unser Nationalfeiertag. Was für ein Aufbruch war das 1990? Was für eine Hoffnung und Zukunftsgewissheit. Grundlage für diese deutsche Einheit war die erfolgreiche Friedliche Revolution, waren die vielen mutigen Menschen, die dem SED-Regime ein Ende bereitet haben.

Swine influenza viruses (SIV) are a common and an important cause of respiratory disease in pigs. Pigs can serve as mixing vessels for the evolution of reassortment viruses containing both avian and human signatures, which have the potential to cause pandemics. NS1 protein of influenza A viruses is a major antagonist of host defence and it regulates multiple functions during infection by interacting with a variety of host proteins. Therefore, it is important to study swine viruses and NS1-interacting host factors in order to understand the mechanisms by which NS1 regulates virus replication and exerts its host defense functions. Influenza A viruses enter the host through the respiratory tract and infect epithelial cells in the respiratory tract, which form the primary sites of virus replication in the host. Thus, studying SIV infection in primary swine respiratory epithelial cells (SRECs) would resemble conditions similar to natural infection. The objectives of this study were to identify NS1-interacting host factors in the virus-infected SRECs and to understand the physiological role of at least one of the factors in influenza virus infection. The approaches to meet this objective were to generate a recombinant SIV carrying a Strep-tag in the NS1 protein, infect SRECs with the Strep-tag virus, purify NS1-interacting host protein complex from the infected cells by pull-down using strep-tactin resin and then study the physiological role of one of the NS1-interacting partners during influenza infection. Using a reverse-genetics strategy, a recombinant virus carrying the Strep-tag NS1 was successfully rescued and the SRECs were infected with this recombinant virus. The Strep-tag in the NS1 protein facilitated the isolation of an intact NS1-interacting protein complex and the proteins present in the complex were identified by liquid chromatography-tandem mass spectrometry. The identified proteins were grouped to enrich for different functions using bioinformatics. This gave an insight into the different functions that NS1 may regulate during infection and the potential host partners involved in these functions. Among the host proteins identified as potential interaction partners, RNA helicases were particularly of interest to study. Influenza being an RNA virus, RNA helicases could have important functions in the virus life cycle. Among the identified RNA helicases, DDX3 has been shown to regulate IFNβ induction and affect the life cycle of a number of viruses. However, its function in influenza A virus life cycle has not been studied. Hence, this study explored whether DDX3 has any role in the influenza A virus life cycle. Immunoprecipitation studies revealed viral proteins NP and NS1 as direct interaction partners with DDX3. DDX3 is a known component of stress granules (SGs) and influenza A virus lacking the NS1 gene is reported to induce SG formation. Therefore, the role of DDX3 in SG formation, induced by PR8 influenza A virus lacking NS1 (PR8 del NS1) was explored. The results from this study showed that DDX3 co-localized with NP in SGs indicating that DDX3 may interact with NP in the SGs. NS1 protein was found to inhibit virus-induced SGs and DDX3 downregulation impaired virus-induced SG formation. The contribution of the different domains of DDX3 to viral protein interaction and virus-induced SG formation was also studied. While DDX3 helicase domain did not interact with NS1 and NP, it was essential for DDX3 localization in virus induced SGs. Moreover, DDX3 downregulation resulted in the increased replication of PR8 del NS1virus, accompanied by an impairment of SG induction in infected cells. Since DDX3 is reported to regulate IFNβ induction, the role of DDX3 in influenza A virus induced IFNβ induction was also examined. Using small molecule inhibitors and siRNA-mediated gene knockdown, the RIG-I pathway was identified as the major contributor of influenza induced IFNβ induction in newborn porcine tracheal epithelial (NPTr) cells. DDX3 downregulation and overexpression also showed that DDX3 has an inhibitory effect on IFNβ expression induced by both influenza infection and low molecular weight (LMW) poly I:C treatment, which is also a RIG-I ligand. RNA competition assay to identify the mechanism of DDX3-mediated inhibition, showed that RIG-I binding affinity to its ligands LMW poly I:C and influenza viral RNA (vRNA) is much higher than that of DDX3. Furthermore, DDX3 downregulation enhanced titers of the PR8 del NS1 virus, while it did not affect the titers of the wild-type strains of PR8 and SIV/SK viruses. Overall, the results show that DDX3 has an antiviral role and the SG regulatory function of DDX3 has a profound effect on virus replication than the IFNβ regulatory function.

Expressing foreign proteins in E.coli is a major challenge because they often tend to develop into unsolvable and inactive proteins. They aggregate into so called  inclusion bodies which prevent expression of the protein. This problem might be avoided by fusing the gene of the foreign protein with a soluble protein called solubility tags, which  function is to enhance the solubility of the foreign protein. This report investigates whether Sterol Carrier Protein-2 (SCP-2) could function as a solubility tag. The experiment was carried out by fusing SCP-2 to two recombinant proteins, Green fluorescent protein (GFP) and a form of chloroamphenicol acetyl transferase (CATΔ9). The gene fusion was then inserted into a pET-15 vector and transformed into  the E.coli strain BL21(DE3) to be expressed. The results obtained from Western blot and PageBlue staining indicates that SCP-2 does not enhance the solubility of GFP or CATΔ9 since neither of them was expressed.  Furthermore, previous studies have shown that GFP can in fact be expressed  usingmaltose binding protein (MBP) as a solubility tag. Unfortunately, no success has been made regarding CATΔ9. In conclusion, regarding the results from this report, SCP-2 does not function as a solubility tag. However, further studies should be carried out on SCP-2 with more experiments before rejecting the possibility to use SCP-2 as a solubility tag.

Expression of foreign proteins in host organisms usually results in the development of insoluble, inactive proteins. Further, these proteins have a tendency to form aggregates termed inclusion bodies. However, the formation of inclusion bodies can be avoided by fusing the gene encoding the foreign protein to a highly soluble protein. In this report Sterol Carrier Protein-2 (SCP-2) is reviewed as a possible solubility tag. The experiment was carried out by fusing SCP-2 to one of two i nsoluble proteins, Green fluorescent protein (GFP) or a form of chloramphenicol acetyl transferase (CAT∆9). The protein fusion was then inserted into the vector pET-15b, transformed in Escherichia coli and the yield of actively expressed protein was measured. The results obtained from this study, as evaluated by PageBlue staining and  Western blot, are indicating that SCP-2 does not improve the solubility of GFP or CAT∆9. Nonetheless, the solubility of GFP has earlier been increased by fusing it to the solubility tag maltose-binding protein (MBP).  Producing more soluble forms of CAT∆9  have also been tested but without success. Therefore the conclusion drawn from this experiment is that SCP-2 does not work as a solubility tag, however more research must be performed to conclude this with certainty.