TY - THES U1 - Dissertation / Habilitation A1 - Le, Thi Nguyen Binh T1 - Studying on protein stress response in Staphylococcus aureus N2 - Understanding of the regulatory mechanisms controlling stress gene expression of S.aureus in response to environmental stress is very essential in studying its fitness and virulence. In this work, the changes in protein expression profiles as well as the gene transcription of S.aureus after heat exposure, osmotic stress and in response to the antibiotic puromycin were studied in order to provide detailed insights into the response of S.aureus to various kinds of environmental stress under in vitro conditions, namely: (1) to investigate the global response of S.aureus to heat stress conditions using transcriptomic and proteomic analyses. (2) to study the transcriptome and proteome of S.aureus in response to antibiotic substance puromycin. (3) to define the proteome signatures of S.aureus under NaCl stress condition. (4) to complete the proteome map of cytoplasmic proteins of S.aureus by identifying proteins exclusively synthesized during the exposure to stress. Firstly, the high resolution 2-D protein gel electrophoresis technique combined with MALDI-TOF-MS and a DNA array approach were used to investigate the cellular response of S.aureus to heat stress. A switch from normal growth temperature to high temperature condition revealed complex changes in the protein expression pattern as well as the genes expression profile. The effect of puromycin stress on S.aureus cells was analyzed, using a gel-based proteomic approach and transcriptomic analyses with DNA microarrays. We compared the protein synthesis pattern as well as the transcription data of S.aureus in response to puromycin stress with that in response to heat shock. The results demonstrated that both stress conditions induced specific, overlapping and general responses. Finally, the protein expression profile of S.aureus in response to NaCl stress was analyzed with 2D gel based proteomic approach. Our proteome analyses revealed the repression of the synthesis of many enzymes belong to different metabolism pathways . In summary, the signatures for stress or starvation stimuli can be used as diagnostic tools for the prediction of the mode of action of new antibiotics or for studying the physiological state of cells grown. Expression of the respective genes under in vivo conditions could provide some ideas on the environmental signals that specifically influence the survival of S.aureus within and outside the host. N2 - In dieser Arbeit, die Veraenderungen in der Protein-Expression Profile sowie die Gen-Transkription von Staphylococcus aureus nach Hitze, osmotischen Stress und in Reaktion auf das Antibiotikum Puromycin wurden untersucht, um zu studieren die Reaktion von S.aureus zu verschiedenen Arten von Umweltbelastung unter In-vitro-Bedingungen. KW - Staphylococcus aureus KW - Proteomics KW - Stress Y2 - 2008 U6 - https://nbn-resolving.org/urn:nbn:de:gbv:9-000604-7 UN - https://nbn-resolving.org/urn:nbn:de:gbv:9-000604-7 ER -