Basic research
Influence of protein post-translational modifications on mitochondrial function

Authors: Keresztesová, B., Kunová, N., Bauer, J., Ondrovičová, G., Pevala, V., Kutejová, E.

Post-translational modifications of proteins represent an efficient way for cells to adapt to environmental changes and significantly modulate protein properties. Lysine succinylation has a major impact on protein function because it dramatically changes its charge. In eukaryotes, it mainly affects mitochondrial proteins, since the succinate donor, succinyl-CoA, is primarily formed in the Krebs cycle. In cooperation with the Department of Genetics of PriF UK and the Institute of Chemistry of SAV, we performed a comprehensive proteomic analysis of yeast mitochondria and detected 314 succinylated mitochondrial proteins containing 1763 new succinylation sites. The mitochondrial nucleoid, a complex of mtDNA and proteins, is a structure whose proteins are affected by succinylation. We found that Abf2, a major component of the S. cerevisiae nucleoid responsible for mtDNA packaging, can be succinylated on 13 lysines. In vitro studies have shown that succinylation of Abf2 leads to inhibition of its DNA-binding activity and reduces its sensitivity to cleavage by the ScLon protease.


Projects:

1. VEGA 02/0075/18 – Faktory ovplyvňujúce dynamiku mitochondriálneho nukleoidu (Factors influencing mitochondrial nucleoid  dynamics)
2. APVV-15-0375 – Posttranslačné modifikácie v mitochondriách a ich úloha v patologických procesoch (Posttranslational modifications in mitochondria and their role in pathological processes)
3. APVV-19-0298 – Vzájomná inerakcia proteáz, šaperónov a kináz v mitochodriách pri strese spôsobenom patologickými stavmi (Mutual interaction of proteases, shaperones and kinases in mitochondria in stress caused by pathological conditions)

Publications:

1. FRANKOVSKÝ, J.* - KERESZTESOVÁ, B.* - BELLOVÁ, J. - KUNOVÁ, N. - ČANIGOVÁ, N. - HANAKOVÁ, K. - BAUER, J. - ONDROVIČOVÁ, G. - LUKÁČOVÁ, V. - SIVÁKOVÁ, B. - ZDRÁHAL, Z. - PEVALA, V. - PROCHÁZKOVÁ, K. - NOSEK, J. - BARÁTH, P.** - KUTEJOVÁ, E.** - TOMÁŠKA, Ľ.** The yeast mitochondrial succinylome: Implications for regulation of mitochondrial nucleoids. In Journal of Biological Chemistry, 2021, vol. 297, no. 4, no. 101155 [16] p. (2020: 5.157 - IF, Q2 - JCR, 2.361 - SJR, Q1 - SJR, karentované - CCC).
2. KOTRASOVÁ, V.* - KERESZTESOVÁ, B.* - ONDROVIČOVÁ, G. - BAUER, J. - HAVALOVÁ, H. - PEVALA, V. - KUTEJOVÁ, E.** - KUNOVÁ, N** Mitochondrial kinases and the role of mitochondrial protein phosphorylation in health and disease. In Life-Basel, 2021, vol. 11, p. 82. (2020: 3.817 - IF, Q2 - JCR, 0.973 - SJR, Q1 - SJR, karentované - CCC).
3. HAVALOVÁ, H.* - ONDROVIČOVÁ, G.* - KERESZTESOVÁ, B. - BAUER, J. - PEVALA, V. - KUTEJOVÁ, E.** - KUNOVÁ, N.** Mitochondrial HSP70 chaperone system - the influence of post-translational modifications and involvement in human diseases. In International Journal of Molecular Sciences, 2021, vol. 22, no. 8077. (2020: 5.924 - IF, Q1 - JCR, 1.455 - SJR, Q1 - SJR, karentované - CCC).

Basic research
Promoter cross-recognition of nine stress sigma factor SigB homologues in Streptomyces coelicolor A3 (2)

Authors: Ševčíková, B., Řežuchová, B., Mazuráková, V., Homerová, D., Nováková, R., Fecková, Ľ., Kormanec, J.

Unlike Bacillus subtilis, Streptomyces coelicolor contains nine homologs of the sigma factor SigB, which has a major role in differentiation and response to osmotic stress. Using a heterologous two-plasmid system, we identified 24 promoters recognized by nine SigB homologs (SigBFGHIKLMN). Interestingly,  several promoters were recognized by multiple sigma factors. We verified the promoters in vivo in S. coelicolor A3(2) under conditions of osmotic stress and differentiation. All promoters showed high similarity in the -35 and -10 regions. Immunoblot analysis revealed the presence of SigB under osmotic stress conditions and SigH during morphological differentiation. Together with the phenotypic analysis of the prepared sigB and sigH mutants in S. coelicolor A3(2), these results suggest a dominant role for SigB in the osmotic stress response and a dual role for SigH in the osmotic stress response and morphological differentiation and a complex regulation of the osmotic stress response in relation to morphological differentiation in S. coelicolor.
Projects:
VEGA 2/0026/20 – Signálne kaskády regulácie sigma faktorov RNA polymerázy pri odozve na stres, bunkovej a fyziologickej diferenciácii u pôdnych baktérií rodu Streptomyces. (Signaling cascades in RNA polymerase  sigma factor regulation in response to stress, cell and physiological differentiation of soil bacteria of the genus Streptomyces.)
Publications:

1. ŠEVČÍKOVÁ, Beatrica - REŽUCHOVÁ, Bronislava - MAZURÁKOVÁ, Vladislava. - HOMEROVÁ, Dagmar - NOVÁKOVÁ, Renáta - FECKOVÁ, Ľubomíra - KORMANEC, Ján**. Cross-recognition of promoters by the nine SigB homologues present in Streptomyces coelicolor A3(2). In International Journal of Molecular Sciences, 2021, vol. 22, no. 7849. (2020: 5.924 - IF, Q1 - JCR, 1.455 - SJR, Q1 - SJR, karentované - CCC).
2. KORMANEC, Ján** - REŽUCHOVÁ, Bronislava - NOVÁKOVÁ, Renáta. Screening systems for stable markerless genomic deletions/integrations in Streptomyces species. In Antimicrobial therapies : methods and protocols. - New York : Springer-Verlag, Humana Press, 2021, p. 91-141. ISBN 978-1-0716-1358-0.

Basic research
The role of Clostridioides difficile DivIVA in the formation of the division septum membrane during cell division

Authors: Labajová, N., Barák, I.

DivIVA protein is an important part of the negative cell division regulator Min system in gram-positive bacteria. This protein was identified as a spatial regulator of cell division in the model organism Bacillus subtilis but its homologues are present in many other bacteria, including pathogenic Clostridia species. In addition to its role as a topological regulator of the Min system during bacterial cell division, DivIVA is involved in chromosome segregation during sporulation, genetic competence, and cell wall synthesis. DivIVA localizes to the regions of high membrane curvature, such as cell poles and the site of cell division. Negative curvature recognition was previously thought to be the main mechanism by which DivIVA binds to these specific sites. We have shown that Clostridioides difficile DivIVA preferentially binds to membranes containing negatively charged phospholipids, especially cardiolipin. Our observations suggest that DivIVA may play a more complex and so far unknown active role in the formation of the division septum membrane during the cell division.


Projects:

1. VEGA 2/0001/09 - Ako bunka nájde miesto asymetrického delenia počas sporulácie Bacillus subtilis. (How a cell finds a site of asymmetric division during sporulation of Bacillus subtilis.)
2. APVV-18-0104 – Asymetrické bunkové delenie počas tvorby bakteriálnej endospóry. (Asymmetric cell division during bacterial endospore formation.)

Publications:
LABAJOVÁ, Naďa** - BARANOVA, Natalia - JURÁSEK, Miroslav - VÁCHA, Robert** - LOOSE, Martin - BARÁK, Imrich**. Cardiolipin-containing lipid membranes attract the bacterial cell division protein divIVA. In International Journal of Molecular Sciences, 2021, vol. 22, no. 8350. (2020: 5.924 - IF, Q1 - JCR, 1.455 - SJR, Q1 - SJR, karentované - CCC).

Applied research
Poly (ℇ-caprolactone) encapsulated nanoparticles with essential oils with increased antimicrobial activity

Authors: Kapustová (Rusková), M., Puškárová, A., Bučková, M., Pangallo., D.

Excessive use of synthetic compounds with antimicrobial activity has led to the selection of resistant microorganisms. In this context, the use of plant essential oils (EOs) with antimicrobial activity encapsulated in ecological nanosystems could be a new and significant strategy to overcome this problem. EOs of carvacrol chemotype from Thymus capitatus and thymol and carvacrol chemotype from Origanum vulgare were encapsulated in biocompatible poly(ε-caprolactone) nanocapsules (NC). These nanosystems showed antibacterial, antifungal and antibiofilm activities against Staphylococcus aureus, Escherichia coli and Candida albicans. EO nanosuspensions were also tested against a panel of fourteen fungal strains belonging to Ascomycota and Basidiomycota phylum. In addition, cytotoxicity and genotoxicity of EO nanosuspensions were also evaluated. Our investigations demonstrate the ability of poly(ε-caprolactone) NCs loaded with thyme and oregano EOs to reduce microbial and biofilm growth. Hence they could be useful and ecological alternative in the development of new antimicrobial strategies.


Projects:
VEGA 2/0059/19 – Kombinácia nanočastíc a esenciálnych olejov na zmiernenie biologického poškodenia rôznych typov stavebných materiálov (A combination of nanoparticles and essential oils in mitigation of biological damage to various types of building materials)
Publications:

1. KAPUSTOVÁ, Magdaléna* - PUŠKÁROVÁ, Andrea - BUČKOVÁ, Mária - GRANATA, Giuseppe* - NAPOLI, Edoardo - ANNUŠOVÁ, Adriana - MESÁROŠOVÁ, Monika - KOZICS, Katarína - PANGALLO, Domenico** - GERACI, Coradda**. Biofilm inhibition by biocompatible poly(epsilon-caprolactone) nanocapsules loaded with essential oils and their cyto/genotoxicity to human keratinocyte cell line. In International Journal of Pharmaceutics, 2021, vol. 606, no. 12, art. no. 120846. (2020: 5.875 - IF, Q1 - JCR, 1.153 - SJR, Q1 - SJR, karentované - CCC).
2. KAPUSTOVÁ, Magdaléna* - GRANATA, Giuseppe* - NAPOLI, Edoardo - PUŠKÁROVÁ, Andrea - BUČKOVÁ, Mária - PANGALLO, Domenico** - GERACI, C.**. Nanoencapsulated essential oils with enhanced antifungal activity for potential application on agri-food, material and environmental fields. In Antibiotics, 2021, vol. 10, no. 31. (2020: 4.639 - IF, Q2 - JCR, 0.960 - SJR, Q1 - SJR).

International research projects
Antibacterial activity of honey as a qualitative parameter of honey linked to its biological functionality

Authors: Majtán, J., Bučeková, M., Godočíková, J., Bugárová, V.

The current valid quality parameters for honey do not take into account its unique biological functionality, especially as honey belongs to the group of so-called functional foods. In our scientific work, we characterized the influence of different types of carbohydrate sources (nectar, sucrose and invert sugar) on the overall antibacterial activity of bee-processed products. It was shown that the antibacterial activity of the honey samples was significantly higher compared to the activity of the processed solution of sucrose or invert sugar. However, we did not notice any differences in the content of the glucose oxidase enzyme or in the levels of accumulated hydrogen peroxide between individual bee-processed products. The above results show that, in addition to bee substances, botanical substances are also partly responsible for the antibacterial activity. The antibacterial activity of honey could represent a suitable parameter determining the quality of honey with regard to its biological functionality.



Projects:
VEGA 2/0004/18 – Vplyv včelieho enzýmu glukózooxidáza na antibakteriálne vlastnosti medu a charakterizácia jeho produkcie a aktivity v podhltanových žľazách včely medonosnej -Apis mellifera (Influence of bee enzyme glucose oxidase on antibacterial properties of honey and characterization of its production and activity in the pharyngeal glands of honey bee -Apis mellifera).
Publications:

1. BUGÁROVÁ, V. - GODOČÍKOVÁ, J. - BUČEKOVÁ, M. - BRODSCHNEIDER, R. - MAJTÁN, J.**. Effects of the carbohydrate sources nectar, sucrose and invert sugar on antibacterialactivity of honey and bee-processed syrups. In Antibiotics, 2021, vol. 10, no. 985. (2020: 4.639 - IF, Q2 - JCR, 0.960 - SJR, Q1 - SJR).
2. MAJTÁN, J.** - BUČEKOVÁ, M. - KAFANTARIS, I. - SZWEDA, P. - HAMMER, K. - MOSSIALOS, D. Honey antibacterial activity: A neglected aspect of honey quality assurance as functional food. In Trends in Food Science and Technology, 2021, vol. 118, p. 870-886. (2020: 12.563 - IF, Q1 - JCR, 2.676 - SJR, Q1 - SJR, karentované - CCC).