SpvC is a Salmonella effector with phosphothreonine lyase activity on host mitogen-activated protein kinases.

SpvC is encoded by the Salmonella virulence plasmid. We have investigated the biochemical function of SpvC and the mechanism by which it is secreted by bacteria and translocated into infected macrophages. We constructed a strain carrying a deletion in spvC and showed that the strain is attenuated for systemic virulence in mice.

Signature-tagged mutagenesis: barcoding mutants for genome-wide screens.

DNA signature tags (molecular barcodes) facilitate functional screens by identifying mutants in mixed populations that have a reduced or increased adaptation to a particular environment. Many innovative adaptations and refinements in the technology have been described since its original use with Salmonella; they have yielded a wealth of information on a broad range of biological processes--mainly in bacteria, but also in yeast and other fungi, viruses, parasites and, most recently, in mammalian cells. By combining whole-genome microarrays and comprehensive ordered libraries of mutants, high-throughput functional screens can now be achieved on a genomic scale.

Dynamin is required for F-actin assembly and pedestal formation by enteropathogenic Escherichia coli (EPEC).

After attaching to human intestinal epithelial cells, enteropathogenic Escherichia coli (EPEC) induces the formation of an actin-rich pedestal-like structure. The signalling pathway leading to pedestal formation is initiated by the bacterial protein Tir, which is inserted into the host cell plasma membrane. The domain exposed on the cell surface binds to another bacterial protein, intimin, while one of the cytoplasmic domains binds the adaptor protein Nck.

Proton motive force-dependent Hoechst 33342 transport by the ABC transporter LmrA of Lactococcus lactis.

The fluorescent compound Hoechst 33342 is a substrate for many multidrug resistance (MDR) transporters and is widely used to characterize their transport activity. We have constructed mutants of the adenosine triphosphate (ATP) binding cassette (ABC)-type MDR transporter LmrA of Lactococcus lactis that are defective in ATP hydrolysis. These mutants and wild-type LmrA exhibited an atypical behavior in the Hoechst 33342 transport assay.

What do proton motive force driven multidrug resistance transporters have in common?

The extensive progress of genome sequencing projects in recent years has demonstrated that multidrug resistance (MDR) transporters are widely spread among all domains of life. This indicates that they play crucial roles in the survival of organisms. Moreover, antibiotic and chemotherapeutic treatments have revealed that microorganisms and cancer cells may use MDR transporters to fight the cytotoxic action of drugs.

Energetics of wild-type and mutant multidrug resistance secondary transporter LmrP of Lactococcus lactis.

LmrP, a proton/multidrug antiporter of Lactococcus lactis, transports a variety of cationic substrates. Previously, two membrane-embedded acidic residues, Asp142 and Glu327, have been reported to be important for multidrug transport activity of LmrP. Here we show that neither Glu327 nor Asp142 is essential for ethidium binding but that Glu327 is a critical residue for the high affinity binding of Hoechst 33342.

Comparison of planning and using free time among students of the Faculty of Pharmacy and the Faculty of Nursing and Health Sciences.

The work presents a research of the group of third year students from two faculties of the Medical University in Lublin. The aim of the research was find out the correlation and differences in the ways of managing and using the so-called 'leisure time'; in relation to stable factors, as well as the system and the direction of studies and environmental factors, dependent on the influences of the psychosociological surrounding. 114 students of the Faculty of Pharmacy and also 55 daily and 51 extramural students of the Faculty of Nursing and Health Education were examined.

ydaG and ydbA of Lactococcus lactis encode a heterodimeric ATP-binding cassette-type multidrug transporter.

Multidrug resistance (MDR)-type transporters mediate the active extrusion of structurally and functionally dissimilar compounds from the cells, thereby rendering cells resistant to a range of drugs. The ydaG and ydbA genes of Lactococcus lactis encode two ATP-binding cassette half-transporters, which both share homology with MDR proteins such as LmrA from L. lactis or the mammalian P-glycoprotein.

Facilitated drug influx by an energy-uncoupled secondary multidrug transporter.

The majority of bacterial multidrug resistance transporters belong to the class of secondary transporters. LmrP is a proton/drug antiporter of Lactococcus lactis that extrudes positively charged lipophilic substrates from the inner leaflet of the membrane to the external medium. This study shows that LmrP is a true secondary transporter.

Non-radiative deactivation pathways of subphthalocyanine and subnaphthalocyanine dyes and of their mixture.

Subphthalocyanine and subnaphthalocyanine dyes and their mixture were investigated by means of the spectroscopic and photoelectric methods. Absorption, fluorescence, steady-state and time-resolved photothermal measurements for the dyes and their mixture were done in order to get information about the radiative and non-radiative deactivation processes as competetive processes to charge separation. It was shown that energy transfer between the dyes improved the photocurrent generation in photoelectrochemical cells (PEC) based on In(2)O(3) and SnO(2) as an electrode.

Ways of spending leisure time by the third year-students of the Faculty of Pharmacy, Medical University of Lublin.

The aim of the study was the assessment of leisure time among third-year students from the Faculty of Pharmacy of the Medical University of Lublin. It analysed quantity of time devoted to school activity and ways of spending free time. The study involved 114 students (82 women and 32 men).

The Escherichia coli multidrug transporter MdfA catalyzes both electrogenic and electroneutral transport reactions.

The resistance of cells to many drugs simultaneously (multidrug resistance) often involves the expression of membrane transporters (Mdrs); each recognizes and expels a broad spectrum of chemically unrelated drugs from the cell. The Escherichia coli Mdr transporter MdfA is able to transport differentially charged substrates in exchange for protons. This includes neutral compounds, namely chloramphenicol and thiamphenicol, and lipophilic cations such as tetraphenylphosphonium and ethidium.

[Hygiene during leisure time among third year students from the Department of Nursing and Health Sciences].

The aim of the study was the assessment of hygiene of leisure time among third year students from Faculty of Nursing and Health Science of Lublin Medical Academy. It analysed passive and active ways of spending free time. The study involved 106 students (55 stationary and 51 extramural) and it was conducted by means of questionnaire.

Multidrug transporters and antibiotic resistance in Lactococcus lactis.

The Gram-positive bacterium Lactococcus lactis produces two distinct multidrug transporters, designated LmrA and LmrP, that both confer resistance to a wide variety of cationic lipophilic cytotoxic compounds as well as to many clinically relevant antibiotics. While LmrP is a proton/drug antiporter that belongs to the major facilitator superfamily of secondary transporters, LmrA is an ATP-dependent primary transporter that belongs to the ATP-binding cassette superfamily of transport proteins. Both LmrA and LmrP function as "hydrophobic vacuum cleaners" by excreting lipophilic cationic compounds from the inner leaflet of the membrane directly into the external water phase.

Acidic residues in the lactococcal multidrug efflux pump LmrP play critical roles in transport of lipophilic cationic compounds.

The proton motive force-driven efflux pump LmrP confers multidrug resistance on Lactococcus lactis cells by extruding a wide variety of lipophilic cationic compounds from the inner leaflet of the cytoplasmic membrane to the exterior of the cell. LmrP contains one cysteine (Cys(270)), which was replaced by alanine. This cysteine-less variant was used in a cysteine scanning accessibility approach.

An ABC-type multidrug transporter of Lactococcus lactis possesses an exceptionally broad substrate specificity.

LmrA is a 590-amino acid membrane protein which confers multidrug resistance on Lactococcus lactis cells by extruding amphiphilic compounds from the inner leaflet of the cytoplasmic membrane at the expense of ATP hydrolysis. Its structural and functional characteristics place it in the P-glycoprotein cluster of the ATP-binding cassette transporter superfamily, making it the first prokaryotic multidrug transporter of this cluster. The number of compounds recognized and transported by LmrA is remarkably vast and includes many lipophilic cations as well as a record of eight classes of clinically relevant broad-spectrum antibiotics.