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SYSTEMY REGULACYJNE EKSPRESJI GENÓW
U STAPHYLOCOCCUS AUREUS
Ksenia Szymanek*, Andrzej Młynarczyk, Grażyna Młynarczyk
Katedra i Zakład Mikrobiologii Lekarskiej Warszawskiego Uniwersytetu Medycznego ul. Chałubińskiego 5, 02-004 Warszawa
Wpłynęło w sierpniu 2008 r.
1. Wstęp. 2. Dwuskładnikowe systemy przekazywania sygnału (TCSTS - two component signal transduction system). 2.1. System agr. 2.1.1. Organizacja genetyczna systemu agr. 2.1.2. Struktura i dojrzewanie cząsteczki autoinduktora AIP. 2.1.3. Aktywacja przekazywania sygnału w TCSTS. 2.1.3.1. Oddziaływanie ligand-sensor w systemie quorum sensing. 2.1.3.2. Aktywacja domeny białka efektora - AgrA. 2.1.4. Region intergeniczny systemu agr. 2.1.5. RNA III. 2.1.5.1. Struktura i organizacja. 2.1.5.2. Funkcja. 2.1.6. Regulacja systemu agr. 2.1.6.1. Autoregulacja zależna od AgrA. 2.1.6.2. Regulacja zależna od SarA. 2.1.6.3. Regulacja zależna od rapItraP. 2.1.7. Zróżnicowanie i znaczenie systemu agr. 2.2. Inne systemy TCSTS uczestniczące w regulacji ekspresji genów S. aureus. 3. Inne czynniki regulacyjne ekspresji genów S. aureus, nie będące TCSTS. 4. Podsumowanie
Regulatory systems of gene expression in Staphylococcus aureus
Abstract: Staphylococcus aureus is one of the most common human pathogens. The expression of genes in S. aureus, including these encoding yirulence factors, seems to be dependent on many inner- and extracellular agents (pH, CO2, cell density, autoinducer concentration, the phase of growth). Each of these signals may actiyate a distinct cell regulatory system via a different pathway. Up to date many molecular mechanisms engaged in the global regulation of virulence factors have been identified. Sixteen of them, for example: agrA/C, saeS/R, arlS/R, srrAJB (srhS/R) lytS/R, rap/traP belong to the two-component signal transduction systems. Each of them consists of a sensor histidine kinase and a response regulator protein. These systems, including ąuorum sensing systems, are sensitive to environmental signals. The second class of global regulatory systems are proteins belonging to the SarA-family of proteins, which together with other alternative transcriptional factors, such as RNA III, MgrA, Rot, SigmaB, may determine the yirulent pheno-type by binding to the promoter regions of regulated genes. Moreover, the mechanisms of bacterial patho genesis may be modulated in the proteolytic way by ClpP protein and also at the translational level by the antisense mechanism involving RNA III molecules. Thanks to these regulatory mechanisms, bacteria are able to colonize and cause infections almost in every tissue of human body.
1. Introduction. 2. TCSTS - two component signal transduction system. 2.1. agr system. 2.1.1. Genetic organization of agr. 2.1.2. Structure and maturation of autoinducer peptide (AIP). 2.1.3. Activation of signal transduction in TCSTS. 2.1.3.1. Ligand-sensor interaction in the quorum sensing system. 2.1.3.2. Activation of response regulator domain of AgrA. 2.1.4. Intergenic region of agr. 2.1.5. RNA III. 2.1.5.1. Structure and organization. 2.1.5.2. Function. 2.1.6. Regulation of agr system. 2.1.6.1. AgrA-dependent autoregulation. 2.1.6.2. SarA-dependent regulation. 2.1.6.3. rap/traP-dependent regulation. 2.1.7. Diversity and role of agr system. 2.2. Other TCSTS mechanisms of regulation of gene expression in S. aureus. 3. Non-TCSTS mechanisms of regulation of gene expression in S. aureus. 4. Summary
Słowa kluczowe: agr, czynniki wirulencji, dwuskładnikowe systemy regulacyjne, RNA III, Staphylococcus aureus
Key words: agr, RNA III, Staphylococcus aureus, two component regulatory systems, virulence factors
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