Basic research
The role of Lon protease in mitochondrial nucleoide dynamics

Authors: Kunová, N., Ondrovičová, G., Bauer, J., Bellová, J., Ambro, Ľ., Martináková, L., Kutejová, E., Pevala, V.

Mitochondria belong to the important organelles of eukaryotic cells, whose homeostasis disruption in human cells causes several serious diseases. We have confirmed that in yeast, the Lon protease is part of the mitochondrial nucleoid, which is essential for the maintenance of mitochondrial function. In vitro studies of the regulation level of some mitochondrial proteins by Lon protease showed that yeast proteins Mgm101a Abf2, as well as Twinkle helicase in the human nucleoid, and ribosomal protein MrpL32, are recognized and cleaved by the respective Lon protease. While the cleavage of Mgm101, Abf2 and MrpL32 is significantly affected by the presence of DNA or RNA, the cleavage of Twinkle helicase is not affected by the presence of nucleic acid. In the case of the Mgm101 protein, these studies were supplemented by in vivo experiments monitoring the level of Mgm101 in different S. cerevisiae genetic backgrounds. The studies show that the regulation of the level of the monitored proteins plays a significant role in the stabilization and dynamics of the mitochondrial nucleoid.


Projects:

1. VEGA 2/0113/14 - ATP-závislé proteázy a homeostáza mitochondrií (ATP-dependent proteases and mitochondrial homeostasis)
2. APVV-15-0375 - Posttranslačné modifikácie v mitochodriách a ich úloha v patologických procesoch (Posttranslational modifications in mitochondria and their role in pathological processes)

Publications:
KUNOVÁ, N. - ONDROVIČOVÁ, G. - BAUER, J. - BELLOVÁ, J. - AMBRO, Ľ. - MARTINÁKOVÁ, L. - KOTRASOVÁ, V. - KUTEJOVÁ, E. - PEVALA, V. The role of Lon-mediated proteolysis in the dynamics of mitochondrial nucleic acid-protein complexes. In Scientific Reports, 2017, vol. 7, art. no. 631. (2016: 4.259 - IF, Q1 - JCR, 1.692 - SJR, Q1 - SJR)

Basic research
Discovery of a unique fusion between Heme Hybrid Peroxidase Type B and a carbohydrate-binding domain in filamentous fungi

Authors: Zámocký, M., Janeček, Š., Kamlárová, A., Harichová, J.

We successfully characterized before unknown gene subfamily of hybrid heme peroxidases from the genomes of several filamentous fungi. These special oxidoreductases contain a unique fusion of an N-terminal highly conserved heme peroxidase domain with variable C-terminal saccharide binding domains (CBM 21 or CBM 34 type). Their coordinated action of peroxide bond cleavage and binding of carbohydrates derived from the plant cell wall was demonstrated for a recombinantly expressed protein from the ascomycete fungus Magnaporthe oryzae, which is considered one of the most dangerous phytopathogens. Hybrid B-type peroxidases are unique fusion proteins that can effectively protect a variety of dangerous fungal phytopathogens from the oxidative burst of the plant host, representing a fundamental defense mechanism of higher plants to destroy invading pathogens.


Projects:

1. VEGA 2/0021/14 – Fylogenomický a fyziologický výskum reakcií na oxidačný stres v termofilných a mezofilných mikroorganizmoch (Phylogenomic and physiological research of reactions to oxidative stress in thermophilic and mesophilic microorganisms)
2. VEGA 2/0146/17 – Evolúcia amylolytických enzýmov (Evolution of amylolytic enzymes)

Publications:
ZÁMOCKÝ, M. - JANEČEK, Š. - OBINGER, C. Fungal Hybrid B heme peroxidases - unique fusions of a heme peroxidase domain with a carbohydrate-binding domain. In Scientific Reports, 2017, vol. 7, art. no. 9393. (2016: 4.259 - IF, Q1 - JCR, 1.692 - SJR, Q1 - SJR)
 

Applied research
Essential oils: their antimicrobial effect and disinfection of our cultural heritage

Authors: Puškárová, A., Bučková, M., Kraková, L., Pangallo, D.

Six essential oils (oregano, thyme, clove, lavender, sage and thuja oil) showed different antibacterial and antifungal properties. The antimicrobial activity of essential oils was tested on pathogenic bacteria (Escherichia coli, Salmonella typhimurium, Yersinia enterocolitica, Staphylococcus aureus, Listeria monocytogenes and Enterococcus faecalis) and environmental bacteria (Bacillus cereus, Arthrobacter protophormiae, Pseudomonas fragi) as well as microscopic fungi (Chaetomium globosum, Penicillium chrysogenum, Cladosporium cladosporoides, Alternaria alternata and Aspergillus fumigatus). Oregano, thyme, clove and thuja oil at low concentrations showed strong antibacterial activity against all tested strains. These essential oils showed different fungistatic and fungicidal effects when testing direct contact of microorganisms as well as vapors. Essential oil vapors were also used in a specific disinfection system to remove microbial contamination on the two tested books. On September 30, 2017, at the Center for Scientific and Technical Information of the Slovak Republic, we organized a workshop entitled "The science behind essential oils".


Projects:
VEGA 2/0061/17 – Inovatívne stratégie dezinfekcie: vplyv esenciálnych olejov na mikroflóru a materiály objektov kultúrneho dedičstva (Innovative disinfection strategies: the impact of essential oils on microflora and heritage materials)
Publications:

1. PUŠKÁROVÁ, A. - BUČKOVÁ, M. - KRAKOVÁ, L. - PANGALLO, D. - KOZICS, K. The antibacterial and antifungal activity of six essential oils and their cyto/genotoxicity to human HEL 12469 cells. In Scientific Reports, 2017, vol. 7, no. 1, art. no. 8211. (2016: 4.259 - IF, Q1 - JCR, 1.692 - SJR, Q1 - SJR)
2. PIETRZAK, K. - OTLEWSKA, A. - DANIELEWICZ, D. - DYBKA, K. - PANGALLO, D. - KRAKOVÁ, L. - PUŠKÁROVÁ, A. - BUČKOVÁ, M. - SCHOLTZ, V. - ĎUROVIČ, M. - SURMA-ŚLUSARSKA, B. - DEMNEROVA, K. - GUTAROWSKA, B. Disinfection of archival documents using thyme essential oil, silver nanoparticles misting and low temperature plasma. In Journal of cultural heritage, 2017, vol. 24, p. 69-77. (2016: 1.838 - IF, Q2 - JCR, 0.582 - SJR, Q1 - SJR)

Applied research
Bee antibacterial peptide defensin-1 as an immunomodulator in the wound healing process

Authors: Majtán, J., Bučeková, M.

Peptide defensin-1 is secreted by the bee into royal jelly and honey. Defensin-1 exhibits antibacterial effects against Gram-positive bacteria, and therefore its primary role is to protect the bee brood and the bee against bacterial pathogens such as Paenibacillus larvae. Since honey and royal jelly are used in modern medicine for wound healing, in our study we focused on the characterization of its biological effects in the healing process of excisional wounds, where we elucidated its immunomodulating effects. We found that defensin-1 in its recombinant form stimulated the production of matrix metalloproteinase 9 (MMP-9) from human keratinocytes and had a positive effect on their migration and proliferation in vitro. The obtained laboratory results were supported by preclinical testing of recombinant defensin-1 in an animal model on sterile excisional wounds. Defensin-1 significantly stimulated the process of re-epithelialization of wounds and the formation of scars and therefore can find application in the regeneration of skin defects. This study confirmed that bee products are not only antibacterial products but also products with an immunomodulating effect in the management of wound healing.


Projects:
VEGA 2/0007/14: Antibakteriálne a imunomodulačné vlastnosti včelieho peptidu defenzínu-1 v procese hojenia chronických rán (Antibacterial and immunomodulatory properties of bee peptide defensin-1 in the process of chronic wound healing)
Publications:
BUČEKOVÁ, M. - SOJKA, M. - VALACHOVÁ, I. - MARTINOTTI, S. - RANZATO, E. - SZEP, Z. - MAJTAN, V. - KLAUDINY, J. - MAJTÁN, J. Bee-derived antibacterial peptide, defensin-1, promotes wound re-epithelialisation in vitro and in vivo. In Scientific Reports, 2017, vol. 7, no. 1, art. no. 7340. (2016: 4.259 - IF, Q1 - JCR, 1.692 - SJR, Q1 - SJR)
 

International research projects
Development of a biosensor for the detection of the production of cluster-specific secondary metabolites

Authors: Kormanec, J., Nováková, R.

Current advances in the sequencing of bacterial genomes have revealed that the capacity of Streptomycetes, as the most important producers of biologically active substances, is much higher than it was assumed. Their genomes contain dozens of gene clusters for various secondary metabolites, most of which are silent under laboratory conditions. Their activation can bring new effective biologically active substances. For this purpose, in cooperation with our co-workers, we developed a sensitive biosensor for the activation of these silent gene clusters. In the Streptomyces lividans strain, there is a silent cpk cluster for the antibiotic coelimycin, near which the SLIV_06715 gene for a potential repressor of the TetR family is located. Using the bpsA reporter gene we characterized, located behind a promoter negatively regulated by this repressor, we proved the activation of this gene cluster through the interaction of coelimycin with this repressor and the subsequent unblocking of the expression of this gene cluster. This biosensor will enable the detection of activated biosynthetic clusters for secondary metabolites, which will enable the discovery of new biologically active substances.


Projects:
APVV-15-0410: Syntetická biológia pre produkciu nových biologicky aktívnych látok u streptomycét (Synthetic biology for the production of new biologically active substances in Streptomycetes)
Publications:

1. SUN, Y.-Q. - BUSCHE, T. - RUCKERT, C. - PAULUS, C. - REBETS, Y. - NOVÁKOVÁ, R. - KALINOWSKI, J. - LUZHETSKYY, A. - KORMANEC, J. - SEKUROVA, O.N. - ZOTCHEV, S.B. Development of a biosensor concept to detect the production of cluster-specific secondary metabolites. In ACS Synthetic Biology, 2017, vol. 6, p. 1026–1033. (2016: 5.382 - IF, Q1 - JCR, 2.793 - SJR, Q1 - SJR)
2. REBETS, Y. - KORMANEC, J. - LUZHETSKYY, A. - BERNAERTS, K. - ANNÉ, J. Cloning and expression of metagenomic DNA in Streptomyces lividans and subsequent fermentation for optimized production. In Metagenomics : methods and Protocols. - New York : Springer, 2017, p. 99-144. (2016: 0.585 - SJR, Q3 - SJR)