Dorota Kuczynska-Wisnik

Publications (3)10.21 Total impact

• Article: The formation of persister cells in stationary-phase cultures of Escherichia coli is associated with the aggregation of endogenous proteins.

  Daria Leszczynska, Ewelina Matuszewska, Dorota Kuczynska-Wisnik, Beata Furmanek-Blaszk, Ewa Laskowska
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  ABSTRACT: Persister cells (persisters) are transiently tolerant to antibiotics and usually constitute a small part of bacterial populations. Persisters remain dormant but are able to re-grow after antibiotic treatment. In this study we found that the frequency of persisters correlated to the level of protein aggregates accumulated in E. coli stationary-phase cultures. When 3-(N-morpholino) propanesulfonic acid or an osmolyte (trehalose, betaine, glycerol or glucose) were added to the growth medium at low concentrations, proteins were prevented from aggregation and persister formation was inhibited. On the other hand, acetate or high concentrations of osmolytes enhanced protein aggregation and the generation of persisters. We demonstrated that in the E. coli stationary-phase cultures supplemented with MOPS or a selected osmolyte, the level of protein aggregates and persister frequency were not correlated with such physiological parameters as the extent of protein oxidation, culturability, ATP level or membrane integrity. The results described here may help to understand the mechanisms underlying persister formation.
  PLoS ONE 01/2013; 8(1):e54737. · 4.09 Impact Factor
• Article: Escherichia coli heat-shock proteins IbpA and IbpB affect biofilm formation by influencing the level of extracellular indole.

  Dorota Kuczyńska-Wiśnik, Ewelina Matuszewska, Ewa Laskowska
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  ABSTRACT: The development of Escherichia coli biofilm requires the differential expression of various genes implicated in cell signalling, stress responses, motility and the synthesis of structures responsible for cell attachment. The ibpAB operon is among the stress-response genes most induced during growth of the E. coli biofilm. In this study we demonstrated, to our knowledge for the first time, that the lack of IbpAB proteins in E. coli cells inhibited the formation of biofilm at the air-liquid interface, although it allowed normal planktonic growth. We showed that ibpAB mutant cells experienced endogenous oxidative stress, which might result from a decreased catalase activity. The endogenous oxidative stress in ibpAB cells led to increased expression of tryptophanase, an enzyme which catalyses the synthesis of indole. We demonstrated that the formation of biofilm by the ibpAB mutant was delayed due to the increase in the extracellular concentration of indole, which is known to play the role of a signal molecule, inhibiting biofilm growth.
  Microbiology 10/2009; 156(Pt 1):148-57. · 3.06 Impact Factor
• Article: Escherichia coli heat-shock proteins IbpA/B are involved in resistance to oxidative stress induced by copper.

  Ewelina Matuszewska, Joanna Kwiatkowska, Dorota Kuczynska-Wisnik, Ewa Laskowska
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  ABSTRACT: The small heat-shock proteins IbpA/B are molecular chaperones that bind denatured proteins and facilitate their subsequent refolding by the ATP-dependent chaperones DnaK, DnaJ, GrpE and ClpB. In this report, we demonstrate that IbpA/B participate in the defence against copper-induced stress under aerobic conditions. In the presence of oxygen, DeltaibpA/B cells exhibit increased sensitivity to copper ions and accumulate elevated amounts of oxidized proteins, while under oxygen depletion, the DeltaibpA/B mutation has no effect on copper tolerance. This indicates that IbpA/B protect Escherichia coli cells from oxidative damage caused by copper. We show that AdhE, one of the proteins exposed to oxidation, is protected by IbpA/B against copper-mediated inactivation both in vivo and in vitro.
  Microbiology 06/2008; 154(Pt 6):1739-47. · 3.06 Impact Factor
• Article: Transcription of the ibpB Heat-Shock Gene Is under Control of ς 32- and ς 54-Promoters, a Third Regulon of Heat-Shock Response

  Dorota Kuczyńska-Wisńik, Ewa Laskowska, Alina Taylor
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  ABSTRACT: The expression of the ibpAibpB heat-shock operon of Escherichia coli was found previously not to conform to the known pattern of expression of the ς32-regulated operons because the rpoH gene mutation inactivating the ς32 protein did not abolish the ibp induction. We show here that this effect can depend partly on the ς54-promoter that is inducible by heat shock, located upstream of the ibpB, the distal gene of the operon. It may also depend on a metabolic signal, postulated by others, and possibly required for the expression of the ibpAB genes. Thus, the ibpB gene can be translated from the transcript covering the whole operon starting from the ς32-promoter and from the ibpB gene transcript starting from the ς54-promoter. These results indicate that the ibpB gene is a second member of the ς54-heat-shock regulon in E. coli besides pspA-E operon. Thus, heat-shock response involves three regulons controlled by ς32, ς24, and ς54 RNA polymerase subunits.
  Biochemical and Biophysical Research Communications - BIOCHEM BIOPHYS RES COMMUN. 01/2001; 284(1):57-64.