D-alanyl-D-alanine carboxypeptidase, product of dacD gene in Francisella, belongs to penicillin binding proteins (PBPs) and is involved in remodeling of newly synthetized peptidoglycan. In E. coli, PBPs are synthetized in various growth phases and they are able to substitute each other to a certain extent. The DacD protein was found to be accumulated in fraction enriched in membrane proteins from severely attenuated dsbA deletion mutant strain. It has been presumed that the DsbA is not a virulence factor by itself but that its substrates, whose correct folding and topology are dependent on the DsbA oxidoreductase and/or isomerase activities, are the primary virulence factors. Here we demonstrate that Francisella DacD is required for intracellular replication and virulence in mice. The dacD insertion mutant strain showed higher sensitivity to acidic pH, high temperature and high osmolarity when compared to the wild-type. Eventually, transmission electron microscopy revealed differences in mutant bacteria in both the size and defects in outer membrane underlying its SDS and serum sensitivity. Taken together these results suggest DacD plays an important role in Francisella pathogenicity.

• Klíčová slova
• DacD, Francisella, carboxypeptidase, membrane defects, penicillin binding proteins, phagosomal escape, virulence,
• MeSH
• antibakteriální látky farmakologie   MeSH
• buněčná stěna metabolismus   MeSH
• Francisella tularensis účinky léků   růst a vývoj   patogenita   MeSH
• karboxypeptidasa štěpící D-Ala-D-Ala vazby serinového typu genetika   metabolismus   MeSH
• kultivované buňky MeSH
• myši inbrední BALB C MeSH
• myši MeSH
• peptidoglykan biosyntéza   MeSH
• proteindisulfidisomerasy genetika   MeSH
• proteiny vázající penicilin genetika   metabolismus   MeSH
• transmisní elektronová mikroskopie MeSH
• tularemie mikrobiologie   patologie   MeSH
• virulence genetika   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, U.S. Gov't, Non-P.H.S. MeSH
• Názvy látek
• antibakteriální látky MeSH
• karboxypeptidasa štěpící D-Ala-D-Ala vazby serinového typu MeSH
• peptidoglykan MeSH
• proteindisulfidisomerasy MeSH
• proteiny vázající penicilin MeSH

Francisella tularensis is a highly virulent intracellular pathogen with the capacity to infect a variety of hosts including humans. One of the most important proteins involved in F. tularensis virulence and pathogenesis is the protein DsbA. This protein is annotated as a lipoprotein with disulfide oxidoreductase/isomerase activity. Therefore, its interactions with different substrates, including probable virulence factors, to assist in their proper folding are anticipated. We aimed to use the immunopurification approach to find DsbA (gene locus FTS_1067) interacting partners in F. tularensis subsp. holarctica strain FSC200 and compare the identified substrates with proteins which were found in our previous comparative proteome analysis. As a result of our work two FTS_1067 substrates, D-alanyl-D-alanine carboxypeptidase family protein and HlyD family secretion protein, were identified. Bacterial two-hybrid systems were further used to test their relevance in confirming FTS_1067 protein interactions.

• Klíčová slova
• FTS_1067 protein, Francisella tularensis, bacterial two-hybrid assay, immunopurification,
• MeSH
• bakteriální proteiny genetika   metabolismus   MeSH
• faktory virulence genetika   metabolismus   MeSH
• Francisella tularensis genetika   metabolismus   patogenita   MeSH
• lipoproteiny genetika   metabolismus   MeSH
• vazba proteinů MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• bakteriální proteiny MeSH
• faktory virulence MeSH
• lipoproteiny MeSH

Francisella tularensis is the causative agent of the potentially lethal disease tularemia. Due to a low infectious dose and ease of airborne transmission, Francisella is classified as a category A biological agent. Despite the possible risk to public health, there is no safe and fully licensed vaccine. A potential vaccine candidate, an attenuated live vaccine strain, does not fulfil the criteria for general use. In this review, we will summarize existing and new candidates for live attenuated and subunit vaccines.

• MeSH
• bakteriální vakcíny imunologie   MeSH
• Francisella tularensis imunologie   MeSH
• lidé MeSH
• objevování léků trendy   MeSH
• tularemie imunologie   prevence a kontrola   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH
• Názvy látek
• bakteriální vakcíny MeSH

Francisella tularensis the etiological agent of tularaemia is one of the most infectious human pathogen known. Our knowledge about its key virulence factors has increased recently but it still remains a lot to explore. One of the described essential virulence factors is membrane lipoprotein FTS_1067 (nomenclature of F. tularensis subsp. holarctica strain FSC200) with homology to the protein family of disulphide oxidoreductases DsbA. Lipoprotein consists of two different domains: the C-terminal DsbA_Com1-like domain (DSBA-like) and the N-terminal FKBP-type peptidyl-prolyl cis/trans isomerases (FKBP_N-like). To uncover the biological role of these domains, we created bacterial strain with deletion of the DSBA-like domain. This defect in gene coding for lipoprotein FTS_1067 led to high in vivo attenuation associated with the ability to induce host protective immunity. Analyses performed with the truncated recombinant protein showed that the absence of DSBA-like domain revealed the loss of thiol/disulphide oxidoreductase activity and, additionally, confirmed the role of the FKBP_N-like domain in the FTS_1067 oligomerization and chaperone-like function. Finally, we verified that only full-length form of FTS_1067 recombinant protein possesses the isomerase activity. Based on our results, we proposed that for the correct FTS_1067 protein function both domains are needed.

• Klíčová slova
• chaperone, copper ions, oligomerization, protein disulphide isomerase, virulence factor,
• MeSH
• bakteriální proteiny genetika   metabolismus   MeSH
• faktory virulence genetika   metabolismus   MeSH
• Francisella tularensis genetika   růst a vývoj   patogenita   MeSH
• lipoproteiny genetika   metabolismus   MeSH
• membránové proteiny genetika   metabolismus   MeSH
• modely nemocí na zvířatech MeSH
• mutantní proteiny genetika   metabolismus   MeSH
• myši inbrední BALB C MeSH
• sekvenční delece MeSH
• tularemie mikrobiologie   patologie   MeSH
• virulence MeSH
• zvířata MeSH
• Check Tag
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• bakteriální proteiny MeSH
• faktory virulence MeSH
• lipoproteiny MeSH
• membránové proteiny MeSH
• mutantní proteiny MeSH