Helena Sztajer

Technische Universität Braunschweig

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Irene Wagner‐Döbler

Technische Universität Braunschweig

Jürgen Tomasch

Czech Academy of Sciences, Institute of Microbiology

Zhi-Luo Deng

Helmholtz Centre for Infection Research

Manfred Rohde

Helmholtz Centre for Infection Research

Szymon P. Szafrański

Medizinische Hochschule Hannover

Ulrich Menge

Helmholtz Centre for Infection Research

Leopold Flohé

University of Padua

Barbara Lejczak

Wrocław University of Science and Technology

Michael Jarek

Helmholtz Centre for Infection Research

Michael Reck

Helmholtz Centre for Infection Research

Cooperative Institutions

Helmholtz Centre for Infection Research

Technische Universität Braunschweig

German Center for Infection Research

University of Wrocław

Wrocław University of Science and Technology

University of Cartagena

AGH University of Krakow

Leibniz Institute DSMZ – German Collection of Microorganisms and Cell Cultures

Gesellschaft zur Förderung von Medizin-, Bio- und Umwelttechnologien

Medizinische Hochschule Hannover

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Multi-omics analysis reveals the molecular response to heat stress in a “red tide” dinoflagellate

bioRxiv (Cold Spring Harbor Laboratory) (2022)

Katherine E. Dougan Zhi-Luo Deng Lars Wöhlbrand Carsten Reuse Boyke Bunk

Abstract “Red tides” are harmful algal blooms (HABs) caused by dinoflagellate microalgae that accumulate toxins lethal to other organisms, including humans via consumption of contaminated seafood. Increasingly frequent, HABs are driven by a combination of environmental factors including nutrient enrichment, particularly in warm waters. Here, we present the de novo assembled genome (~4.75 Gbp), transcriptome, proteome, and metabolome from Prorocentrum cordatum , a globally abundant, bloom-forming dinoflagellate. Using axenic algal cultures, we studied the molecular mechanisms that underpin response to temperature stress, which is relevant to current ocean warming trends. We discovered a complementary interplay between RNA editing and exon usage that regulates the expression and functional diversity of biomolecules, reflected by reduction in photosynthesis, central metabolism, and protein synthesis. Our multi-omics analyses uncover the molecular response to heat stress in an important HAB species, which is driven by complex gene structures in a large, high-G+C genome, combined with multi-level transcriptional regulation.

Dinoflagellate

Metabolome

Proteome

10.1101/2022.07.25.501386

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Citations (7)

Bioindication of mutagenic and carcinogenic pollutants in waters of the Oława River.

PubMed (1985)

M. Pawlaczyk‐Szpilowa Helena Sztajer T. M. Traczewska

Samples of raw waters from the Oława River, chlorinated raw water, raw water filtered through activated charcoal and treated and chlorinated water before and after ozonization were examined with the use of the Ames test for potential carcinogenic activity. Positive results were obtained for raw water with Salmonella typhimurium strains TA 98 and TA 1535 and for chlorinated raw water with strain TA 1537.

Raw water

Ames test

Charcoal

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Citations (1)

The Delta Subunit of RNA Polymerase, RpoE, Is a Global Modulator ofStreptococcus mutansEnvironmental Adaptation

Journal of Bacteriology (2010)

Xiaoli Xue Jürgen Tomasch Helena Sztajer Irene Wagner‐Döbler

The delta subunit of RNA polymerase, RpoE, is widespread in low-G+C Gram-positive bacteria and is thought to play a role in enhancing transcriptional specificity by blocking RNA polymerase binding at weak promoter sites and stimulating RNA synthesis by accelerating core enzyme recycling. Despite the well-studied biochemical properties of RpoE, a role for this protein in vivo has not been defined in depth. In this study, we show that inactivation of rpoE in the human dental caries pathogen Streptococcus mutans causes impaired growth and loss of important virulence traits, including biofilm formation, resistance to antibiotics, and tolerance to environmental stresses. Complementation of the mutant with rpoE expressed in trans restored its phenotype to wild type. The luciferase fusion reporter showed that rpoE was highly transcribed throughout growth and that acid and hydrogen peroxide stresses repressed rpoE expression. Transcriptome profiling of wild-type and ΔrpoE cells in the exponential and early stationary phase of growth, under acid and hydrogen peroxide stress and under both stresses combined, revealed that genes involved in histidine synthesis, malolactic fermentation, biofilm formation, and antibiotic resistance were downregulated in the ΔrpoE mutant under all conditions. Moreover, the loss of RpoE resulted in dramatic changes in transport and metabolism of carbohydrates and amino acids. Interestingly, differential expression, mostly upregulation, of 330 noncoding regions was found. In conclusion, this study demonstrates that RpoE is an important global modulator of gene expression in S. mutans which is required for optimal growth and environmental adaptation.

Sigma factor

10.1128/jb.00653-10

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Citations (41)

Thiol-dependent peroxidases care little about homology-based assignments of function

Redox Report (2003)

Leopold Flohé Timo Jaeger Sandra Pilawa Helena Sztajer

AbstractThiol-dependent peroxidase systems are reviewed with special emphasis on their potential use as drug targets. The basic catalytic mechanism of the two major thiol-peroxidase families, the glutathione peroxidases and the peroxiredoxins, are reasonably well understood. Sequence-based predictions of substrate specificities are still unsatisfactory. GPx-type enzymes are not generally specific for GSH but may specifically react with CXXC motifs as present in thioredoxins or tryparedoxins. Inversely, the peroxiredoxin family that was believed to be specific for CXXC-type proteins, also comprises glutathione peroxidases. Since structure-based predictions of function are also limited by small data bases, the increasing number of sequences emerging from genome projects require enzymatic characterization and genetic proof of relevance before they can be classified as drug targets.

Peroxiredoxin

Homology

10.1179/135100003225002862

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Citations (28)

Characterization of mleR, a positive regulator of malolactic fermentation and part of the acid tolerance response in Streptococcus mutans

BMC Microbiology (2010)

André Lemme Helena Sztajer Irene Wagner‐Döbler

One of the key virulence determinants of Streptococcus mutans, the primary etiological agent of human dental caries, is its strong acid tolerance. The acid tolerance response (ATR) of S. mutans comprises several mechanisms that are induced at low pH and allow the cells to quickly adapt to a lethal pH environment. Malolactic fermentation (MLF) converts L-malate to L-lactate and carbon dioxide and furthermore regenerates ATP, which is used to translocate protons across the membrane. Thus, MLF may contribute to the aciduricity of S. mutans but has not been associated with the ATR so far.Here we show that the malolactic fermentation (mle) genes are under the control of acid inducible promoters which are induced within the first 30 minutes upon acid shock in the absence of malate. Thus, MLF is part of the early acid tolerance response of S. mutans. However, acidic conditions, the presence of the regulator MleR and L-malate were required to achieve maximal expression of all genes, including mleR itself. Deletion of mleR resulted in a decreased capacity to carry out MLF and impaired survival at lethal pH in the presence of L-malate. Gel retardation assays indicated the presence of multiple binding sites for MleR. Differences in the retardation patterns occurred in the presence of L-malate, thus demonstrating its role as co-inducer for transcriptional regulation.This study shows that the MLF gene cluster is part of the early acid tolerance response in S. mutans and is induced by both low pH and L-malate.

Inducer

Malic acid

10.1186/1471-2180-10-58

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Citations (47)

The effect of culture conditions on lipolytic productivity of Penicillium citrinum

Biotechnology Letters (1989)

Helena Sztajer Irena Maliszewska

Penicillium citrinum

Inducer

Carbon source

10.1007/bf01026848

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Citations (52)

Microbial Lipases in Biotechnology

De Gruyter eBooks (1988)

Helena Sztajer E. Zboińska

10.1515/9783112581766-011

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Citations (0)

Bacterial short-chain acyl-CoA oxidase: production, purification and characterization

Applied Microbiology and Biotechnology (1993)

Helena Sztajer Gabriele Wagner Rolf D. Schmid

Arthrobacter

Flavin adenine dinucleotide

Molecular mass

Acyl-CoA

Flavoprotein

10.1007/bf00164454

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Citations (5)

ATP‐sensitive association of mortalin with the IL‐1 receptor type I

BioFactors (1999)

Gudrun Sacht Regina Brigelius‐Flohé Michael Kieß Helena Sztajer Leopold Flohé

Abstract Interleukin‐1 (IL‐1) is a major proinflammatory cytokine mediating local and systemic responses of the immune system. Two types of IL‐1 receptors are known, but only the IL‐1 receptor type I initiates biological responses. Here we show that two proteins with nucleic acid binding potential and mortalin, a member of the HSP70‐family, are associated with the IL‐1 receptor type I irrespective of IL‐1 binding. The association of mortalin with the IL‐1 receptor type I is specifically reversed by ATP concentrations in the physiological range. Other nucleotides are not or much less effective. The in vitro dissociation of mortalin effects neither the receptor association nor the activity of IRAK, which initiates the IL‐1‐dependent phosphorylation cascade. The roles of the receptor‐associated proteins are therefore discussed in the context of receptor internalisation.

Association (psychology)

10.1002/biof.5520090107

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Citations (51)

Differential Binding Characteristics and Cellular Inhibition by Soluble VEGF Receptors 1 and 2

Experimental Cell Research (1998)

Wolfgang Roeckl Dalit Hecht Helena Sztajer Johannes Waltenberger Avner Yayon

Cell surface receptor

10.1006/excr.1998.4039

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Citations (135)